From 546a9d8519ed137b2804a3f5a3659003039dd49c Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 19 Jun 2014 14:57:10 -0700 Subject: rcu: Export debug_init_rcu_head() and and debug_init_rcu_head() Currently, call_rcu() relies on implicit allocation and initialization for the debug-objects handling of RCU callbacks. If you hammer the kernel hard enough with Sasha's modified version of trinity, you can end up with the sl*b allocators recursing into themselves via this implicit call_rcu() allocation. This commit therefore exports the debug_init_rcu_head() and debug_rcu_head_free() functions, which permits the allocators to allocated and pre-initialize the debug-objects information, so that there no longer any need for call_rcu() to do that initialization, which in turn prevents the recursion into the memory allocators. Reported-by: Sasha Levin Suggested-by: Thomas Gleixner Signed-off-by: Paul E. McKenney Acked-by: Thomas Gleixner Looks-good-to: Christoph Lameter --- include/linux/rcupdate.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 5a75d19aa661..13bbfbde41b9 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -358,9 +358,19 @@ void wait_rcu_gp(call_rcu_func_t crf); * initialization. */ #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD +void init_rcu_head(struct rcu_head *head); +void destroy_rcu_head(struct rcu_head *head); void init_rcu_head_on_stack(struct rcu_head *head); void destroy_rcu_head_on_stack(struct rcu_head *head); #else /* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */ +static inline void init_rcu_head(struct rcu_head *head) +{ +} + +static inline void destroy_rcu_head(struct rcu_head *head) +{ +} + static inline void init_rcu_head_on_stack(struct rcu_head *head) { } -- cgit v1.2.3 From 4a81e8328d3791a4f99bf5b436d050f6dc5ffea3 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 20 Jun 2014 16:49:01 -0700 Subject: rcu: Reduce overhead of cond_resched() checks for RCU Commit ac1bea85781e (Make cond_resched() report RCU quiescent states) fixed a problem where a CPU looping in the kernel with but one runnable task would give RCU CPU stall warnings, even if the in-kernel loop contained cond_resched() calls. Unfortunately, in so doing, it introduced performance regressions in Anton Blanchard's will-it-scale "open1" test. The problem appears to be not so much the increased cond_resched() path length as an increase in the rate at which grace periods complete, which increased per-update grace-period overhead. This commit takes a different approach to fixing this bug, mainly by moving the RCU-visible quiescent state from cond_resched() to rcu_note_context_switch(), and by further reducing the check to a simple non-zero test of a single per-CPU variable. However, this approach requires that the force-quiescent-state processing send resched IPIs to the offending CPUs. These will be sent only once the grace period has reached an age specified by the boot/sysfs parameter rcutree.jiffies_till_sched_qs, or once the grace period reaches an age halfway to the point at which RCU CPU stall warnings will be emitted, whichever comes first. Reported-by: Dave Hansen Signed-off-by: Paul E. McKenney Cc: Andi Kleen Cc: Christoph Lameter Cc: Mike Galbraith Cc: Eric Dumazet Reviewed-by: Josh Triplett [ paulmck: Made rcu_momentary_dyntick_idle() as suggested by the ktest build robot. Also fixed smp_mb() comment as noted by Oleg Nesterov. ] Merge with e552592e (Reduce overhead of cond_resched() checks for RCU) Signed-off-by: Paul E. McKenney --- Documentation/kernel-parameters.txt | 6 ++ include/linux/rcupdate.h | 36 ---------- kernel/rcu/tree.c | 140 ++++++++++++++++++++++++++++-------- kernel/rcu/tree.h | 6 +- kernel/rcu/tree_plugin.h | 2 +- kernel/rcu/update.c | 18 ----- kernel/sched/core.c | 7 +- 7 files changed, 125 insertions(+), 90 deletions(-) (limited to 'include') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 6eaa9cdb7094..910c3829f81d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2785,6 +2785,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. leaf rcu_node structure. Useful for very large systems. + rcutree.jiffies_till_sched_qs= [KNL] + Set required age in jiffies for a + given grace period before RCU starts + soliciting quiescent-state help from + rcu_note_context_switch(). + rcutree.jiffies_till_first_fqs= [KNL] Set delay from grace-period initialization to first attempt to force quiescent states. diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 13bbfbde41b9..6a94cc8b1ca0 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -44,7 +44,6 @@ #include #include #include -#include #include extern int rcu_expedited; /* for sysctl */ @@ -299,41 +298,6 @@ static inline void rcu_user_hooks_switch(struct task_struct *prev, bool __rcu_is_watching(void); #endif /* #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) */ -/* - * Hooks for cond_resched() and friends to avoid RCU CPU stall warnings. - */ - -#define RCU_COND_RESCHED_LIM 256 /* ms vs. 100s of ms. */ -DECLARE_PER_CPU(int, rcu_cond_resched_count); -void rcu_resched(void); - -/* - * Is it time to report RCU quiescent states? - * - * Note unsynchronized access to rcu_cond_resched_count. Yes, we might - * increment some random CPU's count, and possibly also load the result from - * yet another CPU's count. We might even clobber some other CPU's attempt - * to zero its counter. This is all OK because the goal is not precision, - * but rather reasonable amortization of rcu_note_context_switch() overhead - * and extremely high probability of avoiding RCU CPU stall warnings. - * Note that this function has to be preempted in just the wrong place, - * many thousands of times in a row, for anything bad to happen. - */ -static inline bool rcu_should_resched(void) -{ - return raw_cpu_inc_return(rcu_cond_resched_count) >= - RCU_COND_RESCHED_LIM; -} - -/* - * Report quiscent states to RCU if it is time to do so. - */ -static inline void rcu_cond_resched(void) -{ - if (unlikely(rcu_should_resched())) - rcu_resched(); -} - /* * Infrastructure to implement the synchronize_() primitives in * TREE_RCU and rcu_barrier_() primitives in TINY_RCU. diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index f1ba77363fbb..625d0b0cd75a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -206,6 +206,70 @@ void rcu_bh_qs(int cpu) rdp->passed_quiesce = 1; } +static DEFINE_PER_CPU(int, rcu_sched_qs_mask); + +static DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { + .dynticks_nesting = DYNTICK_TASK_EXIT_IDLE, + .dynticks = ATOMIC_INIT(1), +#ifdef CONFIG_NO_HZ_FULL_SYSIDLE + .dynticks_idle_nesting = DYNTICK_TASK_NEST_VALUE, + .dynticks_idle = ATOMIC_INIT(1), +#endif /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */ +}; + +/* + * Let the RCU core know that this CPU has gone through the scheduler, + * which is a quiescent state. This is called when the need for a + * quiescent state is urgent, so we burn an atomic operation and full + * memory barriers to let the RCU core know about it, regardless of what + * this CPU might (or might not) do in the near future. + * + * We inform the RCU core by emulating a zero-duration dyntick-idle + * period, which we in turn do by incrementing the ->dynticks counter + * by two. + */ +static void rcu_momentary_dyntick_idle(void) +{ + unsigned long flags; + struct rcu_data *rdp; + struct rcu_dynticks *rdtp; + int resched_mask; + struct rcu_state *rsp; + + local_irq_save(flags); + + /* + * Yes, we can lose flag-setting operations. This is OK, because + * the flag will be set again after some delay. + */ + resched_mask = raw_cpu_read(rcu_sched_qs_mask); + raw_cpu_write(rcu_sched_qs_mask, 0); + + /* Find the flavor that needs a quiescent state. */ + for_each_rcu_flavor(rsp) { + rdp = raw_cpu_ptr(rsp->rda); + if (!(resched_mask & rsp->flavor_mask)) + continue; + smp_mb(); /* rcu_sched_qs_mask before cond_resched_completed. */ + if (ACCESS_ONCE(rdp->mynode->completed) != + ACCESS_ONCE(rdp->cond_resched_completed)) + continue; + + /* + * Pretend to be momentarily idle for the quiescent state. + * This allows the grace-period kthread to record the + * quiescent state, with no need for this CPU to do anything + * further. + */ + rdtp = this_cpu_ptr(&rcu_dynticks); + smp_mb__before_atomic(); /* Earlier stuff before QS. */ + atomic_add(2, &rdtp->dynticks); /* QS. */ + smp_mb__after_atomic(); /* Later stuff after QS. */ + break; + } + local_irq_restore(flags); +} + /* * Note a context switch. This is a quiescent state for RCU-sched, * and requires special handling for preemptible RCU. @@ -216,19 +280,12 @@ void rcu_note_context_switch(int cpu) trace_rcu_utilization(TPS("Start context switch")); rcu_sched_qs(cpu); rcu_preempt_note_context_switch(cpu); + if (unlikely(raw_cpu_read(rcu_sched_qs_mask))) + rcu_momentary_dyntick_idle(); trace_rcu_utilization(TPS("End context switch")); } EXPORT_SYMBOL_GPL(rcu_note_context_switch); -static DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = { - .dynticks_nesting = DYNTICK_TASK_EXIT_IDLE, - .dynticks = ATOMIC_INIT(1), -#ifdef CONFIG_NO_HZ_FULL_SYSIDLE - .dynticks_idle_nesting = DYNTICK_TASK_NEST_VALUE, - .dynticks_idle = ATOMIC_INIT(1), -#endif /* #ifdef CONFIG_NO_HZ_FULL_SYSIDLE */ -}; - static long blimit = 10; /* Maximum callbacks per rcu_do_batch. */ static long qhimark = 10000; /* If this many pending, ignore blimit. */ static long qlowmark = 100; /* Once only this many pending, use blimit. */ @@ -243,6 +300,13 @@ static ulong jiffies_till_next_fqs = ULONG_MAX; module_param(jiffies_till_first_fqs, ulong, 0644); module_param(jiffies_till_next_fqs, ulong, 0644); +/* + * How long the grace period must be before we start recruiting + * quiescent-state help from rcu_note_context_switch(). + */ +static ulong jiffies_till_sched_qs = HZ / 20; +module_param(jiffies_till_sched_qs, ulong, 0644); + static bool rcu_start_gp_advanced(struct rcu_state *rsp, struct rcu_node *rnp, struct rcu_data *rdp); static void force_qs_rnp(struct rcu_state *rsp, @@ -853,6 +917,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp, bool *isidle, unsigned long *maxj) { unsigned int curr; + int *rcrmp; unsigned int snap; curr = (unsigned int)atomic_add_return(0, &rdp->dynticks->dynticks); @@ -893,27 +958,43 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp, } /* - * There is a possibility that a CPU in adaptive-ticks state - * might run in the kernel with the scheduling-clock tick disabled - * for an extended time period. Invoke rcu_kick_nohz_cpu() to - * force the CPU to restart the scheduling-clock tick in this - * CPU is in this state. - */ - rcu_kick_nohz_cpu(rdp->cpu); - - /* - * Alternatively, the CPU might be running in the kernel - * for an extended period of time without a quiescent state. - * Attempt to force the CPU through the scheduler to gain the - * needed quiescent state, but only if the grace period has gone - * on for an uncommonly long time. If there are many stuck CPUs, - * we will beat on the first one until it gets unstuck, then move - * to the next. Only do this for the primary flavor of RCU. + * A CPU running for an extended time within the kernel can + * delay RCU grace periods. When the CPU is in NO_HZ_FULL mode, + * even context-switching back and forth between a pair of + * in-kernel CPU-bound tasks cannot advance grace periods. + * So if the grace period is old enough, make the CPU pay attention. + * Note that the unsynchronized assignments to the per-CPU + * rcu_sched_qs_mask variable are safe. Yes, setting of + * bits can be lost, but they will be set again on the next + * force-quiescent-state pass. So lost bit sets do not result + * in incorrect behavior, merely in a grace period lasting + * a few jiffies longer than it might otherwise. Because + * there are at most four threads involved, and because the + * updates are only once every few jiffies, the probability of + * lossage (and thus of slight grace-period extension) is + * quite low. + * + * Note that if the jiffies_till_sched_qs boot/sysfs parameter + * is set too high, we override with half of the RCU CPU stall + * warning delay. */ - if (rdp->rsp == rcu_state_p && + rcrmp = &per_cpu(rcu_sched_qs_mask, rdp->cpu); + if (ULONG_CMP_GE(jiffies, + rdp->rsp->gp_start + jiffies_till_sched_qs) || ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) { - rdp->rsp->jiffies_resched += 5; - resched_cpu(rdp->cpu); + if (!(ACCESS_ONCE(*rcrmp) & rdp->rsp->flavor_mask)) { + ACCESS_ONCE(rdp->cond_resched_completed) = + ACCESS_ONCE(rdp->mynode->completed); + smp_mb(); /* ->cond_resched_completed before *rcrmp. */ + ACCESS_ONCE(*rcrmp) = + ACCESS_ONCE(*rcrmp) + rdp->rsp->flavor_mask; + resched_cpu(rdp->cpu); /* Force CPU into scheduler. */ + rdp->rsp->jiffies_resched += 5; /* Enable beating. */ + } else if (ULONG_CMP_GE(jiffies, rdp->rsp->jiffies_resched)) { + /* Time to beat on that CPU again! */ + resched_cpu(rdp->cpu); /* Force CPU into scheduler. */ + rdp->rsp->jiffies_resched += 5; /* Re-enable beating. */ + } } return 0; @@ -3491,6 +3572,7 @@ static void __init rcu_init_one(struct rcu_state *rsp, "rcu_node_fqs_1", "rcu_node_fqs_2", "rcu_node_fqs_3" }; /* Match MAX_RCU_LVLS */ + static u8 fl_mask = 0x1; int cpustride = 1; int i; int j; @@ -3509,6 +3591,8 @@ static void __init rcu_init_one(struct rcu_state *rsp, for (i = 1; i < rcu_num_lvls; i++) rsp->level[i] = rsp->level[i - 1] + rsp->levelcnt[i - 1]; rcu_init_levelspread(rsp); + rsp->flavor_mask = fl_mask; + fl_mask <<= 1; /* Initialize the elements themselves, starting from the leaves. */ diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index bf2c1e669691..0f69a79c5b7d 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -307,6 +307,9 @@ struct rcu_data { /* 4) reasons this CPU needed to be kicked by force_quiescent_state */ unsigned long dynticks_fqs; /* Kicked due to dynticks idle. */ unsigned long offline_fqs; /* Kicked due to being offline. */ + unsigned long cond_resched_completed; + /* Grace period that needs help */ + /* from cond_resched(). */ /* 5) __rcu_pending() statistics. */ unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */ @@ -392,6 +395,7 @@ struct rcu_state { struct rcu_node *level[RCU_NUM_LVLS]; /* Hierarchy levels. */ u32 levelcnt[MAX_RCU_LVLS + 1]; /* # nodes in each level. */ u8 levelspread[RCU_NUM_LVLS]; /* kids/node in each level. */ + u8 flavor_mask; /* bit in flavor mask. */ struct rcu_data __percpu *rda; /* pointer of percu rcu_data. */ void (*call)(struct rcu_head *head, /* call_rcu() flavor. */ void (*func)(struct rcu_head *head)); @@ -563,7 +567,7 @@ static bool rcu_nocb_need_deferred_wakeup(struct rcu_data *rdp); static void do_nocb_deferred_wakeup(struct rcu_data *rdp); static void rcu_boot_init_nocb_percpu_data(struct rcu_data *rdp); static void rcu_spawn_nocb_kthreads(struct rcu_state *rsp); -static void rcu_kick_nohz_cpu(int cpu); +static void __maybe_unused rcu_kick_nohz_cpu(int cpu); static bool init_nocb_callback_list(struct rcu_data *rdp); static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq); static void rcu_sysidle_exit(struct rcu_dynticks *rdtp, int irq); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index cbc2c45265e2..02ac0fb186b8 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2404,7 +2404,7 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) * if an adaptive-ticks CPU is failing to respond to the current grace * period and has not be idle from an RCU perspective, kick it. */ -static void rcu_kick_nohz_cpu(int cpu) +static void __maybe_unused rcu_kick_nohz_cpu(int cpu) { #ifdef CONFIG_NO_HZ_FULL if (tick_nohz_full_cpu(cpu)) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 0fb691e63ce6..bc7883570530 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -350,21 +350,3 @@ static int __init check_cpu_stall_init(void) early_initcall(check_cpu_stall_init); #endif /* #ifdef CONFIG_RCU_STALL_COMMON */ - -/* - * Hooks for cond_resched() and friends to avoid RCU CPU stall warnings. - */ - -DEFINE_PER_CPU(int, rcu_cond_resched_count); - -/* - * Report a set of RCU quiescent states, for use by cond_resched() - * and friends. Out of line due to being called infrequently. - */ -void rcu_resched(void) -{ - preempt_disable(); - __this_cpu_write(rcu_cond_resched_count, 0); - rcu_note_context_switch(smp_processor_id()); - preempt_enable(); -} diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3bdf01b494fe..bc1638b33449 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4147,7 +4147,6 @@ static void __cond_resched(void) int __sched _cond_resched(void) { - rcu_cond_resched(); if (should_resched()) { __cond_resched(); return 1; @@ -4166,18 +4165,15 @@ EXPORT_SYMBOL(_cond_resched); */ int __cond_resched_lock(spinlock_t *lock) { - bool need_rcu_resched = rcu_should_resched(); int resched = should_resched(); int ret = 0; lockdep_assert_held(lock); - if (spin_needbreak(lock) || resched || need_rcu_resched) { + if (spin_needbreak(lock) || resched) { spin_unlock(lock); if (resched) __cond_resched(); - else if (unlikely(need_rcu_resched)) - rcu_resched(); else cpu_relax(); ret = 1; @@ -4191,7 +4187,6 @@ int __sched __cond_resched_softirq(void) { BUG_ON(!in_softirq()); - rcu_cond_resched(); /* BH disabled OK, just recording QSes. */ if (should_resched()) { local_bh_enable(); __cond_resched(); -- cgit v1.2.3 From 44ff0254b89079a8a95e652635e760d93196ac1f Mon Sep 17 00:00:00 2001 From: Doug Anderson Date: Thu, 5 Jun 2014 13:35:14 -0700 Subject: clk: exynos5420: Remove aclk66_peric from the clock tree description The "aclk66_peric" clock is a gate clock with a whole bunch of gates underneath it. This big gate isn't very useful to include in our clock tree. If any of the children need to be turned on then the big gate will need to be on anyway. ...and there are plenty of other "big gates" that aren't described in our clock tree, some of which shut off collections of clocks that have no relationship in the hierarchy so are hard to model. "aclk66_peric" is causing earlyprintk problems since it gets disabled as part of the boot process, so let's just remove it. Strangely (and for no good reason) this clock is exported as part of the common clock bindings. Remove it since there are no in-kernel device trees using it and no reason anyone out of tree should refer to it either. Signed-off-by: Doug Anderson Signed-off-by: Tomasz Figa --- drivers/clk/samsung/clk-exynos5420.c | 85 ++++++++++++++++++++++------------ include/dt-bindings/clock/exynos5420.h | 1 - 2 files changed, 55 insertions(+), 31 deletions(-) (limited to 'include') diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c index 9d7d7eed03fd..61eccf0dd72f 100644 --- a/drivers/clk/samsung/clk-exynos5420.c +++ b/drivers/clk/samsung/clk-exynos5420.c @@ -890,8 +890,6 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = { GATE_BUS_TOP, 9, CLK_IGNORE_UNUSED, 0), GATE(0, "aclk66_psgen", "mout_user_aclk66_psgen", GATE_BUS_TOP, 10, CLK_IGNORE_UNUSED, 0), - GATE(CLK_ACLK66_PERIC, "aclk66_peric", "mout_user_aclk66_peric", - GATE_BUS_TOP, 11, CLK_IGNORE_UNUSED, 0), GATE(0, "aclk266_isp", "mout_user_aclk266_isp", GATE_BUS_TOP, 13, 0, 0), GATE(0, "aclk166", "mout_user_aclk166", @@ -994,34 +992,61 @@ static struct samsung_gate_clock exynos5x_gate_clks[] __initdata = { SRC_MASK_FSYS, 24, CLK_SET_RATE_PARENT, 0), /* PERIC Block */ - GATE(CLK_UART0, "uart0", "aclk66_peric", GATE_IP_PERIC, 0, 0, 0), - GATE(CLK_UART1, "uart1", "aclk66_peric", GATE_IP_PERIC, 1, 0, 0), - GATE(CLK_UART2, "uart2", "aclk66_peric", GATE_IP_PERIC, 2, 0, 0), - GATE(CLK_UART3, "uart3", "aclk66_peric", GATE_IP_PERIC, 3, 0, 0), - GATE(CLK_I2C0, "i2c0", "aclk66_peric", GATE_IP_PERIC, 6, 0, 0), - GATE(CLK_I2C1, "i2c1", "aclk66_peric", GATE_IP_PERIC, 7, 0, 0), - GATE(CLK_I2C2, "i2c2", "aclk66_peric", GATE_IP_PERIC, 8, 0, 0), - GATE(CLK_I2C3, "i2c3", "aclk66_peric", GATE_IP_PERIC, 9, 0, 0), - GATE(CLK_USI0, "usi0", "aclk66_peric", GATE_IP_PERIC, 10, 0, 0), - GATE(CLK_USI1, "usi1", "aclk66_peric", GATE_IP_PERIC, 11, 0, 0), - GATE(CLK_USI2, "usi2", "aclk66_peric", GATE_IP_PERIC, 12, 0, 0), - GATE(CLK_USI3, "usi3", "aclk66_peric", GATE_IP_PERIC, 13, 0, 0), - GATE(CLK_I2C_HDMI, "i2c_hdmi", "aclk66_peric", GATE_IP_PERIC, 14, 0, 0), - GATE(CLK_TSADC, "tsadc", "aclk66_peric", GATE_IP_PERIC, 15, 0, 0), - GATE(CLK_SPI0, "spi0", "aclk66_peric", GATE_IP_PERIC, 16, 0, 0), - GATE(CLK_SPI1, "spi1", "aclk66_peric", GATE_IP_PERIC, 17, 0, 0), - GATE(CLK_SPI2, "spi2", "aclk66_peric", GATE_IP_PERIC, 18, 0, 0), - GATE(CLK_I2S1, "i2s1", "aclk66_peric", GATE_IP_PERIC, 20, 0, 0), - GATE(CLK_I2S2, "i2s2", "aclk66_peric", GATE_IP_PERIC, 21, 0, 0), - GATE(CLK_PCM1, "pcm1", "aclk66_peric", GATE_IP_PERIC, 22, 0, 0), - GATE(CLK_PCM2, "pcm2", "aclk66_peric", GATE_IP_PERIC, 23, 0, 0), - GATE(CLK_PWM, "pwm", "aclk66_peric", GATE_IP_PERIC, 24, 0, 0), - GATE(CLK_SPDIF, "spdif", "aclk66_peric", GATE_IP_PERIC, 26, 0, 0), - GATE(CLK_USI4, "usi4", "aclk66_peric", GATE_IP_PERIC, 28, 0, 0), - GATE(CLK_USI5, "usi5", "aclk66_peric", GATE_IP_PERIC, 30, 0, 0), - GATE(CLK_USI6, "usi6", "aclk66_peric", GATE_IP_PERIC, 31, 0, 0), - - GATE(CLK_KEYIF, "keyif", "aclk66_peric", GATE_BUS_PERIC, 22, 0, 0), + GATE(CLK_UART0, "uart0", "mout_user_aclk66_peric", + GATE_IP_PERIC, 0, 0, 0), + GATE(CLK_UART1, "uart1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 1, 0, 0), + GATE(CLK_UART2, "uart2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 2, 0, 0), + GATE(CLK_UART3, "uart3", "mout_user_aclk66_peric", + GATE_IP_PERIC, 3, 0, 0), + GATE(CLK_I2C0, "i2c0", "mout_user_aclk66_peric", + GATE_IP_PERIC, 6, 0, 0), + GATE(CLK_I2C1, "i2c1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 7, 0, 0), + GATE(CLK_I2C2, "i2c2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 8, 0, 0), + GATE(CLK_I2C3, "i2c3", "mout_user_aclk66_peric", + GATE_IP_PERIC, 9, 0, 0), + GATE(CLK_USI0, "usi0", "mout_user_aclk66_peric", + GATE_IP_PERIC, 10, 0, 0), + GATE(CLK_USI1, "usi1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 11, 0, 0), + GATE(CLK_USI2, "usi2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 12, 0, 0), + GATE(CLK_USI3, "usi3", "mout_user_aclk66_peric", + GATE_IP_PERIC, 13, 0, 0), + GATE(CLK_I2C_HDMI, "i2c_hdmi", "mout_user_aclk66_peric", + GATE_IP_PERIC, 14, 0, 0), + GATE(CLK_TSADC, "tsadc", "mout_user_aclk66_peric", + GATE_IP_PERIC, 15, 0, 0), + GATE(CLK_SPI0, "spi0", "mout_user_aclk66_peric", + GATE_IP_PERIC, 16, 0, 0), + GATE(CLK_SPI1, "spi1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 17, 0, 0), + GATE(CLK_SPI2, "spi2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 18, 0, 0), + GATE(CLK_I2S1, "i2s1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 20, 0, 0), + GATE(CLK_I2S2, "i2s2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 21, 0, 0), + GATE(CLK_PCM1, "pcm1", "mout_user_aclk66_peric", + GATE_IP_PERIC, 22, 0, 0), + GATE(CLK_PCM2, "pcm2", "mout_user_aclk66_peric", + GATE_IP_PERIC, 23, 0, 0), + GATE(CLK_PWM, "pwm", "mout_user_aclk66_peric", + GATE_IP_PERIC, 24, 0, 0), + GATE(CLK_SPDIF, "spdif", "mout_user_aclk66_peric", + GATE_IP_PERIC, 26, 0, 0), + GATE(CLK_USI4, "usi4", "mout_user_aclk66_peric", + GATE_IP_PERIC, 28, 0, 0), + GATE(CLK_USI5, "usi5", "mout_user_aclk66_peric", + GATE_IP_PERIC, 30, 0, 0), + GATE(CLK_USI6, "usi6", "mout_user_aclk66_peric", + GATE_IP_PERIC, 31, 0, 0), + + GATE(CLK_KEYIF, "keyif", "mout_user_aclk66_peric", + GATE_BUS_PERIC, 22, 0, 0), /* PERIS Block */ GATE(CLK_CHIPID, "chipid", "aclk66_psgen", diff --git a/include/dt-bindings/clock/exynos5420.h b/include/dt-bindings/clock/exynos5420.h index 97dcb89d37d3..14e1c8f9640c 100644 --- a/include/dt-bindings/clock/exynos5420.h +++ b/include/dt-bindings/clock/exynos5420.h @@ -63,7 +63,6 @@ #define CLK_SCLK_MPHY_IXTAL24 161 /* gate clocks */ -#define CLK_ACLK66_PERIC 256 #define CLK_UART0 257 #define CLK_UART1 258 #define CLK_UART2 259 -- cgit v1.2.3 From 4e26445faad366d67d7723622bf6a60a6f0f5993 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 30 Jun 2014 11:50:28 +0800 Subject: kernfs: introduce kernfs_pin_sb() kernfs_pin_sb() tries to get a refcnt of the superblock. This will be used by cgroupfs. v2: - make kernfs_pin_sb() return the superblock. - drop kernfs_drop_sb(). tj: Updated the comment a bit. [ This is a prerequisite for a bugfix. ] Cc: # 3.15 Acked-by: Greg Kroah-Hartman Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- fs/kernfs/mount.c | 30 ++++++++++++++++++++++++++++++ include/linux/kernfs.h | 1 + 2 files changed, 31 insertions(+) (limited to 'include') diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index d171b98a6cdd..f973ae9b05f1 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -211,6 +211,36 @@ void kernfs_kill_sb(struct super_block *sb) kernfs_put(root_kn); } +/** + * kernfs_pin_sb: try to pin the superblock associated with a kernfs_root + * @kernfs_root: the kernfs_root in question + * @ns: the namespace tag + * + * Pin the superblock so the superblock won't be destroyed in subsequent + * operations. This can be used to block ->kill_sb() which may be useful + * for kernfs users which dynamically manage superblocks. + * + * Returns NULL if there's no superblock associated to this kernfs_root, or + * -EINVAL if the superblock is being freed. + */ +struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns) +{ + struct kernfs_super_info *info; + struct super_block *sb = NULL; + + mutex_lock(&kernfs_mutex); + list_for_each_entry(info, &root->supers, node) { + if (info->ns == ns) { + sb = info->sb; + if (!atomic_inc_not_zero(&info->sb->s_active)) + sb = ERR_PTR(-EINVAL); + break; + } + } + mutex_unlock(&kernfs_mutex); + return sb; +} + void __init kernfs_init(void) { kernfs_node_cache = kmem_cache_create("kernfs_node_cache", diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 17aa1cce6f8e..20f493564917 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -304,6 +304,7 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, struct kernfs_root *root, unsigned long magic, bool *new_sb_created, const void *ns); void kernfs_kill_sb(struct super_block *sb); +struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns); void kernfs_init(void); -- cgit v1.2.3 From 7f502361531e9eecb396cf99bdc9e9a59f7ebd7f Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 30 Jun 2014 01:26:23 -0700 Subject: ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix We have two different ways to handle changes to sk->sk_dst First way (used by TCP) assumes socket lock is owned by caller, and use no extra lock : __sk_dst_set() & __sk_dst_reset() Another way (used by UDP) uses sk_dst_lock because socket lock is not always taken. Note that sk_dst_lock is not softirq safe. These ways are not inter changeable for a given socket type. ipv4_sk_update_pmtu(), added in linux-3.8, added a race, as it used the socket lock as synchronization, but users might be UDP sockets. Instead of converting sk_dst_lock to a softirq safe version, use xchg() as we did for sk_rx_dst in commit e47eb5dfb296b ("udp: ipv4: do not use sk_dst_lock from softirq context") In a follow up patch, we probably can remove sk_dst_lock, as it is only used in IPv6. Signed-off-by: Eric Dumazet Cc: Steffen Klassert Fixes: 9cb3a50c5f63e ("ipv4: Invalidate the socket cached route on pmtu events if possible") Signed-off-by: David S. Miller --- include/net/sock.h | 12 ++++++------ net/ipv4/route.c | 15 ++++++++------- 2 files changed, 14 insertions(+), 13 deletions(-) (limited to 'include') diff --git a/include/net/sock.h b/include/net/sock.h index 173cae485de1..c556fd9b05ac 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1768,9 +1768,11 @@ __sk_dst_set(struct sock *sk, struct dst_entry *dst) static inline void sk_dst_set(struct sock *sk, struct dst_entry *dst) { - spin_lock(&sk->sk_dst_lock); - __sk_dst_set(sk, dst); - spin_unlock(&sk->sk_dst_lock); + struct dst_entry *old_dst; + + sk_tx_queue_clear(sk); + old_dst = xchg(&sk->sk_dst_cache, dst); + dst_release(old_dst); } static inline void @@ -1782,9 +1784,7 @@ __sk_dst_reset(struct sock *sk) static inline void sk_dst_reset(struct sock *sk) { - spin_lock(&sk->sk_dst_lock); - __sk_dst_reset(sk); - spin_unlock(&sk->sk_dst_lock); + sk_dst_set(sk, NULL); } struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 082239ffe34a..3162ea923ded 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1010,7 +1010,7 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) const struct iphdr *iph = (const struct iphdr *) skb->data; struct flowi4 fl4; struct rtable *rt; - struct dst_entry *dst; + struct dst_entry *odst = NULL; bool new = false; bh_lock_sock(sk); @@ -1018,16 +1018,17 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) if (!ip_sk_accept_pmtu(sk)) goto out; - rt = (struct rtable *) __sk_dst_get(sk); + odst = sk_dst_get(sk); - if (sock_owned_by_user(sk) || !rt) { + if (sock_owned_by_user(sk) || !odst) { __ipv4_sk_update_pmtu(skb, sk, mtu); goto out; } __build_flow_key(&fl4, sk, iph, 0, 0, 0, 0, 0); - if (!__sk_dst_check(sk, 0)) { + rt = (struct rtable *)odst; + if (odst->obsolete && odst->ops->check(odst, 0) == NULL) { rt = ip_route_output_flow(sock_net(sk), &fl4, sk); if (IS_ERR(rt)) goto out; @@ -1037,8 +1038,7 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) __ip_rt_update_pmtu((struct rtable *) rt->dst.path, &fl4, mtu); - dst = dst_check(&rt->dst, 0); - if (!dst) { + if (!dst_check(&rt->dst, 0)) { if (new) dst_release(&rt->dst); @@ -1050,10 +1050,11 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu) } if (new) - __sk_dst_set(sk, &rt->dst); + sk_dst_set(sk, &rt->dst); out: bh_unlock_sock(sk); + dst_release(odst); } EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu); -- cgit v1.2.3 From 330d282216d6e4d845a21b72572dc4df4122e8fa Mon Sep 17 00:00:00 2001 From: Zhengyu He Date: Tue, 1 Jul 2014 12:11:47 -0700 Subject: core: fix typo in percpu read_mostly section This fixes a typo that named the read_mostly section of percpu as readmostly. It works fine with SMP because the linker script specifies .data..percpu..readmostly. However, UP kernel builds don't have percpu sections defined and the non-percpu version of the section is called data..read_mostly, so .data..readmostly will float around and may break things unexpectedly. Looking at the original change that introduced data..percpu..readmostly (commit c957ef2c59e952803766ddc22e89981ab534606f), it looks like this was the original intention. Tested: Built UP kernel and confirmed the sections got merged. - Before the patch: $ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly' 38 .data..read_mostly 00004418 0000000000000000 0000000000000000 00431ac0 2**6 50 .data..readmostly 00000014 0000000000000000 0000000000000000 00444000 2**3 - After the patch: $ objdump -h vmlinux.o | grep '\.data\.\.read.*mostly' 38 .data..read_mostly 00004438 0000000000000000 0000000000000000 00431ac0 2**6 Signed-off-by: Zhengyu He Signed-off-by: Filipe Brandenburger Signed-off-by: Tejun Heo --- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/percpu-defs.h | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 471ba48c7ae4..c1c0b0cf39b4 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -693,7 +693,7 @@ . = ALIGN(PAGE_SIZE); \ *(.data..percpu..page_aligned) \ . = ALIGN(cacheline); \ - *(.data..percpu..readmostly) \ + *(.data..percpu..read_mostly) \ . = ALIGN(cacheline); \ *(.data..percpu) \ *(.data..percpu..shared_aligned) \ diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index a5fc7d01aad6..dec01d6c3f80 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -146,10 +146,10 @@ * Declaration/definition used for per-CPU variables that must be read mostly. */ #define DECLARE_PER_CPU_READ_MOSTLY(type, name) \ - DECLARE_PER_CPU_SECTION(type, name, "..readmostly") + DECLARE_PER_CPU_SECTION(type, name, "..read_mostly") #define DEFINE_PER_CPU_READ_MOSTLY(type, name) \ - DEFINE_PER_CPU_SECTION(type, name, "..readmostly") + DEFINE_PER_CPU_SECTION(type, name, "..read_mostly") /* * Intermodule exports for per-CPU variables. sparse forgets about -- cgit v1.2.3 From b6220ad66bcd4a50737eb3c08e9466aa44f3bc98 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 24 Jun 2014 18:05:29 -0700 Subject: sched: Fix compiler warnings Commit 143e1e28cb (sched: Rework sched_domain topology definition) introduced a number of functions with a return value of 'const int'. gcc doesn't know what to do with that and, if the kernel is compiled with W=1, complains with the following warnings whenever sched.h is included. include/linux/sched.h:875:25: warning: type qualifiers ignored on function return type include/linux/sched.h:882:25: warning: type qualifiers ignored on function return type include/linux/sched.h:889:25: warning: type qualifiers ignored on function return type include/linux/sched.h:1002:21: warning: type qualifiers ignored on function return type Commits fb2aa855 (sched, ARM: Create a dedicated scheduler topology table) and 607b45e9a (sched, powerpc: Create a dedicated topology table) introduce the same warning in the arm and powerpc code. Drop 'const' from the function declarations to fix the problem. The fix for all three patches has to be applied together to avoid compilation failures for the affected architectures. Acked-by: Vincent Guittot Acked-by: Benjamin Herrenschmidt Signed-off-by: Guenter Roeck Cc: Russell King Cc: Paul Mackerras Cc: Dietmar Eggemann Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1403658329-13196-1-git-send-email-linux@roeck-us.net Signed-off-by: Ingo Molnar --- arch/arm/kernel/topology.c | 2 +- arch/powerpc/kernel/smp.c | 2 +- include/linux/sched.h | 8 ++++---- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'include') diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 9d853189028b..e35d880f9773 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -275,7 +275,7 @@ void store_cpu_topology(unsigned int cpuid) cpu_topology[cpuid].socket_id, mpidr); } -static inline const int cpu_corepower_flags(void) +static inline int cpu_corepower_flags(void) { return SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN; } diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 51a3ff78838a..1007fb802e6b 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -747,7 +747,7 @@ int setup_profiling_timer(unsigned int multiplier) #ifdef CONFIG_SCHED_SMT /* cpumask of CPUs with asymetric SMT dependancy */ -static const int powerpc_smt_flags(void) +static int powerpc_smt_flags(void) { int flags = SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES; diff --git a/include/linux/sched.h b/include/linux/sched.h index 306f4f0c987a..0376b054a0d0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -872,21 +872,21 @@ enum cpu_idle_type { #define SD_NUMA 0x4000 /* cross-node balancing */ #ifdef CONFIG_SCHED_SMT -static inline const int cpu_smt_flags(void) +static inline int cpu_smt_flags(void) { return SD_SHARE_CPUCAPACITY | SD_SHARE_PKG_RESOURCES; } #endif #ifdef CONFIG_SCHED_MC -static inline const int cpu_core_flags(void) +static inline int cpu_core_flags(void) { return SD_SHARE_PKG_RESOURCES; } #endif #ifdef CONFIG_NUMA -static inline const int cpu_numa_flags(void) +static inline int cpu_numa_flags(void) { return SD_NUMA; } @@ -999,7 +999,7 @@ void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms); bool cpus_share_cache(int this_cpu, int that_cpu); typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); -typedef const int (*sched_domain_flags_f)(void); +typedef int (*sched_domain_flags_f)(void); #define SDTL_OVERLAP 0x01 -- cgit v1.2.3 From d9daa24720891a88bedb93928f57767da96e5c80 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Sat, 28 Jun 2014 01:23:35 +0200 Subject: net: fix circular dependency in of_mdio code Commit 86f6cf4127 (net: of_mdio: add of_mdiobus_link_phydev()) introduced a circular dependency between libphy and of_mdio. depmod: ERROR: /kernel/drivers/net/phy/libphy.ko in dependency cycle! depmod: ERROR: /kernel/drivers/of/of_mdio.ko in dependency cycle! The problem is that of_mdio.c references &mdio_bus_type and libphy now references of_mdiobus_link_phydev. Fix this by not exporting of_mdiobus_link_phydev() from of_mdio.ko. Make it a static function in mdio_bus.c instead. Signed-off-by: Daniel Mack Reported-by: Jeff Mahoney Fixes: 86f6cf4127 (net: of_mdio: add of_mdiobus_link_phydev()) Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/phy/mdio_bus.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ drivers/of/of_mdio.c | 34 ---------------------------------- include/linux/of_mdio.h | 8 -------- 3 files changed, 44 insertions(+), 42 deletions(-) (limited to 'include') diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 2e58aa54484c..4eaadcfcb0fe 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -187,6 +187,50 @@ struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np) return d ? to_mii_bus(d) : NULL; } EXPORT_SYMBOL(of_mdio_find_bus); + +/* Walk the list of subnodes of a mdio bus and look for a node that matches the + * phy's address with its 'reg' property. If found, set the of_node pointer for + * the phy. This allows auto-probed pyh devices to be supplied with information + * passed in via DT. + */ +static void of_mdiobus_link_phydev(struct mii_bus *mdio, + struct phy_device *phydev) +{ + struct device *dev = &phydev->dev; + struct device_node *child; + + if (dev->of_node || !mdio->dev.of_node) + return; + + for_each_available_child_of_node(mdio->dev.of_node, child) { + int addr; + int ret; + + ret = of_property_read_u32(child, "reg", &addr); + if (ret < 0) { + dev_err(dev, "%s has invalid PHY address\n", + child->full_name); + continue; + } + + /* A PHY must have a reg property in the range [0-31] */ + if (addr >= PHY_MAX_ADDR) { + dev_err(dev, "%s PHY address %i is too large\n", + child->full_name, addr); + continue; + } + + if (addr == phydev->addr) { + dev->of_node = child; + return; + } + } +} +#else /* !IS_ENABLED(CONFIG_OF_MDIO) */ +static inline void of_mdiobus_link_phydev(struct mii_bus *mdio, + struct phy_device *phydev) +{ +} #endif /** diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c index a3bf2122a8d5..401b2453da45 100644 --- a/drivers/of/of_mdio.c +++ b/drivers/of/of_mdio.c @@ -182,40 +182,6 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) } EXPORT_SYMBOL(of_mdiobus_register); -/** - * of_mdiobus_link_phydev - Find a device node for a phy - * @mdio: pointer to mii_bus structure - * @phydev: phydev for which the of_node pointer should be set - * - * Walk the list of subnodes of a mdio bus and look for a node that matches the - * phy's address with its 'reg' property. If found, set the of_node pointer for - * the phy. This allows auto-probed pyh devices to be supplied with information - * passed in via DT. - */ -void of_mdiobus_link_phydev(struct mii_bus *mdio, - struct phy_device *phydev) -{ - struct device *dev = &phydev->dev; - struct device_node *child; - - if (dev->of_node || !mdio->dev.of_node) - return; - - for_each_available_child_of_node(mdio->dev.of_node, child) { - int addr; - - addr = of_mdio_parse_addr(&mdio->dev, child); - if (addr < 0) - continue; - - if (addr == phydev->addr) { - dev->of_node = child; - return; - } - } -} -EXPORT_SYMBOL(of_mdiobus_link_phydev); - /* Helper function for of_phy_find_device */ static int of_phy_match(struct device *dev, void *phy_np) { diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h index a70c9493d55a..d449018d0726 100644 --- a/include/linux/of_mdio.h +++ b/include/linux/of_mdio.h @@ -25,9 +25,6 @@ struct phy_device *of_phy_attach(struct net_device *dev, extern struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np); -extern void of_mdiobus_link_phydev(struct mii_bus *mdio, - struct phy_device *phydev); - #else /* CONFIG_OF */ static inline int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) { @@ -63,11 +60,6 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np) { return NULL; } - -static inline void of_mdiobus_link_phydev(struct mii_bus *mdio, - struct phy_device *phydev) -{ -} #endif /* CONFIG_OF */ #if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY) -- cgit v1.2.3 From 5925a0555bdaf0b396a84318cbc21ba085f6c0d3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 2 Jul 2014 02:39:38 -0700 Subject: net: fix sparse warning in sk_dst_set() sk_dst_cache has __rcu annotation, so we need a cast to avoid following sparse error : include/net/sock.h:1774:19: warning: incorrect type in initializer (different address spaces) include/net/sock.h:1774:19: expected struct dst_entry [noderef] *__ret include/net/sock.h:1774:19: got struct dst_entry *dst Signed-off-by: Eric Dumazet Reported-by: kbuild test robot Fixes: 7f502361531e ("ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix") Signed-off-by: David S. Miller --- include/net/sock.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/sock.h b/include/net/sock.h index c556fd9b05ac..156350745700 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1771,7 +1771,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst) struct dst_entry *old_dst; sk_tx_queue_clear(sk); - old_dst = xchg(&sk->sk_dst_cache, dst); + old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); dst_release(old_dst); } -- cgit v1.2.3 From 35f6f45368632f21bd27559c44dbb1cab51d8947 Mon Sep 17 00:00:00 2001 From: Amir Vadai Date: Sun, 29 Jun 2014 11:54:55 +0300 Subject: net/mlx4_en: Don't use irq_affinity_notifier to track changes in IRQ affinity map IRQ affinity notifier can only have a single notifier - cpu_rmap notifier. Can't use it to track changes in IRQ affinity map. Detect IRQ affinity changes by comparing CPU to current IRQ affinity map during NAPI poll thread. CC: Thomas Gleixner CC: Ben Hutchings Fixes: 2eacc23 ("net/mlx4_core: Enforce irq affinity changes immediatly") Signed-off-by: Amir Vadai Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/cq.c | 2 - drivers/net/ethernet/mellanox/mlx4/en_cq.c | 4 ++ drivers/net/ethernet/mellanox/mlx4/en_rx.c | 16 +++++-- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 6 --- drivers/net/ethernet/mellanox/mlx4/eq.c | 69 ++++------------------------ drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 + include/linux/mlx4/device.h | 4 +- 7 files changed, 28 insertions(+), 74 deletions(-) (limited to 'include') diff --git a/drivers/net/ethernet/mellanox/mlx4/cq.c b/drivers/net/ethernet/mellanox/mlx4/cq.c index 80f725228f5b..56022d647837 100644 --- a/drivers/net/ethernet/mellanox/mlx4/cq.c +++ b/drivers/net/ethernet/mellanox/mlx4/cq.c @@ -294,8 +294,6 @@ int mlx4_cq_alloc(struct mlx4_dev *dev, int nent, init_completion(&cq->free); cq->irq = priv->eq_table.eq[cq->vector].irq; - cq->irq_affinity_change = false; - return 0; err_radix: diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c index 4b2130760eed..1213cc71348c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c @@ -128,6 +128,10 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq, mlx4_warn(mdev, "Failed assigning an EQ to %s, falling back to legacy EQ's\n", name); } + + cq->irq_desc = + irq_to_desc(mlx4_eq_get_irq(mdev->dev, + cq->vector)); } } else { cq->vector = (cq->ring + 1 + priv->port) % diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index d2d415732d99..96724170308a 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -40,6 +40,7 @@ #include #include #include +#include #include "mlx4_en.h" @@ -896,16 +897,25 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget) /* If we used up all the quota - we're probably not done yet... */ if (done == budget) { + int cpu_curr; + const struct cpumask *aff; + INC_PERF_COUNTER(priv->pstats.napi_quota); - if (unlikely(cq->mcq.irq_affinity_change)) { - cq->mcq.irq_affinity_change = false; + + cpu_curr = smp_processor_id(); + aff = irq_desc_get_irq_data(cq->irq_desc)->affinity; + + if (unlikely(!cpumask_test_cpu(cpu_curr, aff))) { + /* Current cpu is not according to smp_irq_affinity - + * probably affinity changed. need to stop this NAPI + * poll, and restart it on the right CPU + */ napi_complete(napi); mlx4_en_arm_cq(priv, cq); return 0; } } else { /* Done for now */ - cq->mcq.irq_affinity_change = false; napi_complete(napi); mlx4_en_arm_cq(priv, cq); } diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index 8be7483f8236..ac3dead3792c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -474,15 +474,9 @@ int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget) /* If we used up all the quota - we're probably not done yet... */ if (done < budget) { /* Done for now */ - cq->mcq.irq_affinity_change = false; napi_complete(napi); mlx4_en_arm_cq(priv, cq); return done; - } else if (unlikely(cq->mcq.irq_affinity_change)) { - cq->mcq.irq_affinity_change = false; - napi_complete(napi); - mlx4_en_arm_cq(priv, cq); - return 0; } return budget; } diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c index d954ec1eac17..2a004b347e1d 100644 --- a/drivers/net/ethernet/mellanox/mlx4/eq.c +++ b/drivers/net/ethernet/mellanox/mlx4/eq.c @@ -53,11 +53,6 @@ enum { MLX4_EQ_ENTRY_SIZE = 0x20 }; -struct mlx4_irq_notify { - void *arg; - struct irq_affinity_notify notify; -}; - #define MLX4_EQ_STATUS_OK ( 0 << 28) #define MLX4_EQ_STATUS_WRITE_FAIL (10 << 28) #define MLX4_EQ_OWNER_SW ( 0 << 24) @@ -1088,57 +1083,6 @@ static void mlx4_unmap_clr_int(struct mlx4_dev *dev) iounmap(priv->clr_base); } -static void mlx4_irq_notifier_notify(struct irq_affinity_notify *notify, - const cpumask_t *mask) -{ - struct mlx4_irq_notify *n = container_of(notify, - struct mlx4_irq_notify, - notify); - struct mlx4_priv *priv = (struct mlx4_priv *)n->arg; - struct radix_tree_iter iter; - void **slot; - - radix_tree_for_each_slot(slot, &priv->cq_table.tree, &iter, 0) { - struct mlx4_cq *cq = (struct mlx4_cq *)(*slot); - - if (cq->irq == notify->irq) - cq->irq_affinity_change = true; - } -} - -static void mlx4_release_irq_notifier(struct kref *ref) -{ - struct mlx4_irq_notify *n = container_of(ref, struct mlx4_irq_notify, - notify.kref); - kfree(n); -} - -static void mlx4_assign_irq_notifier(struct mlx4_priv *priv, - struct mlx4_dev *dev, int irq) -{ - struct mlx4_irq_notify *irq_notifier = NULL; - int err = 0; - - irq_notifier = kzalloc(sizeof(*irq_notifier), GFP_KERNEL); - if (!irq_notifier) { - mlx4_warn(dev, "Failed to allocate irq notifier. irq %d\n", - irq); - return; - } - - irq_notifier->notify.irq = irq; - irq_notifier->notify.notify = mlx4_irq_notifier_notify; - irq_notifier->notify.release = mlx4_release_irq_notifier; - irq_notifier->arg = priv; - err = irq_set_affinity_notifier(irq, &irq_notifier->notify); - if (err) { - kfree(irq_notifier); - irq_notifier = NULL; - mlx4_warn(dev, "Failed to set irq notifier. irq %d\n", irq); - } -} - - int mlx4_alloc_eq_table(struct mlx4_dev *dev) { struct mlx4_priv *priv = mlx4_priv(dev); @@ -1409,8 +1353,6 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap, continue; /*we dont want to break here*/ } - mlx4_assign_irq_notifier(priv, dev, - priv->eq_table.eq[vec].irq); eq_set_ci(&priv->eq_table.eq[vec], 1); } @@ -1427,6 +1369,14 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap, } EXPORT_SYMBOL(mlx4_assign_eq); +int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec) +{ + struct mlx4_priv *priv = mlx4_priv(dev); + + return priv->eq_table.eq[vec].irq; +} +EXPORT_SYMBOL(mlx4_eq_get_irq); + void mlx4_release_eq(struct mlx4_dev *dev, int vec) { struct mlx4_priv *priv = mlx4_priv(dev); @@ -1438,9 +1388,6 @@ void mlx4_release_eq(struct mlx4_dev *dev, int vec) Belonging to a legacy EQ*/ mutex_lock(&priv->msix_ctl.pool_lock); if (priv->msix_ctl.pool_bm & 1ULL << i) { - irq_set_affinity_notifier( - priv->eq_table.eq[vec].irq, - NULL); free_irq(priv->eq_table.eq[vec].irq, &priv->eq_table.eq[vec]); priv->msix_ctl.pool_bm &= ~(1ULL << i); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index 0e15295bedd6..624e1939e9ee 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -343,6 +343,7 @@ struct mlx4_en_cq { #define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD) spinlock_t poll_lock; /* protects from LLS/napi conflicts */ #endif /* CONFIG_NET_RX_BUSY_POLL */ + struct irq_desc *irq_desc; }; struct mlx4_en_port_profile { diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index b12f4bbd064c..35b51e7af886 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -578,8 +578,6 @@ struct mlx4_cq { u32 cons_index; u16 irq; - bool irq_affinity_change; - __be32 *set_ci_db; __be32 *arm_db; int arm_sn; @@ -1167,6 +1165,8 @@ int mlx4_assign_eq(struct mlx4_dev *dev, char *name, struct cpu_rmap *rmap, int *vector); void mlx4_release_eq(struct mlx4_dev *dev, int vec); +int mlx4_eq_get_irq(struct mlx4_dev *dev, int vec); + int mlx4_get_phys_port_id(struct mlx4_dev *dev); int mlx4_wol_read(struct mlx4_dev *dev, u64 *config, int port); int mlx4_wol_write(struct mlx4_dev *dev, u64 config, int port); -- cgit v1.2.3 From 48bc03433cfdcac7a3bbb233d5c9f95297a0f5ab Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Sun, 29 Jun 2014 13:10:18 +0200 Subject: ieee802154: reassembly: fix possible buffer overflow The max_dsize attribute in ctl_table for lowpan_frags_ns_ctl_table is configured with integer accessing methods. This patch change the max_dsize attribute to int to avoid a possible buffer overflow. Signed-off-by: Alexander Aring Signed-off-by: David S. Miller --- include/net/netns/ieee802154_6lowpan.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/net/netns/ieee802154_6lowpan.h b/include/net/netns/ieee802154_6lowpan.h index 079030c853d8..e2070960bac0 100644 --- a/include/net/netns/ieee802154_6lowpan.h +++ b/include/net/netns/ieee802154_6lowpan.h @@ -16,7 +16,7 @@ struct netns_sysctl_lowpan { struct netns_ieee802154_lowpan { struct netns_sysctl_lowpan sysctl; struct netns_frags frags; - u16 max_dsize; + int max_dsize; }; #endif -- cgit v1.2.3 From 0b9f7d93ca6109048a4eb06332b666b6e29df4fe Mon Sep 17 00:00:00 2001 From: Aaron Lu Date: Mon, 7 Jul 2014 15:43:51 +0800 Subject: ACPI / i915: ignore firmware requests for backlight change Some Thinkpad laptops' firmware will initiate a backlight level change request through operation region on the events of AC plug/unplug, but since we are not using firmware's interface to do the backlight setting on these affected laptops, we do not want the firmware to use some arbitrary value from its ASL variable to set the backlight level on AC plug/unplug either. Link: https://bugzilla.kernel.org/show_bug.cgi?id=76491 Link: https://bugzilla.kernel.org/show_bug.cgi?id=77091 Reported-and-tested-by: Igor Gnatenko Reported-and-tested-by: Anton Gubarkov Signed-off-by: Aaron Lu Acked-by: Jani Nikula Signed-off-by: Rafael J. Wysocki --- drivers/acpi/video.c | 3 ++- drivers/gpu/drm/i915/intel_opregion.c | 9 +++++++++ include/acpi/video.h | 2 ++ 3 files changed, 13 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index fb9ffe9adc64..5bb1278e9324 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -241,13 +241,14 @@ static bool acpi_video_use_native_backlight(void) return use_native_backlight_dmi; } -static bool acpi_video_verify_backlight_support(void) +bool acpi_video_verify_backlight_support(void) { if (acpi_osi_is_win8() && acpi_video_use_native_backlight() && backlight_device_registered(BACKLIGHT_RAW)) return false; return acpi_video_backlight_support(); } +EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support); /* backlight device sysfs support */ static int acpi_video_get_brightness(struct backlight_device *bd) diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index 2e2c71fcc9ed..4f6b53998d79 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -403,6 +403,15 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp) DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp); + /* + * If the acpi_video interface is not supposed to be used, don't + * bother processing backlight level change requests from firmware. + */ + if (!acpi_video_verify_backlight_support()) { + DRM_DEBUG_KMS("opregion backlight request ignored\n"); + return 0; + } + if (!(bclp & ASLE_BCLP_VALID)) return ASLC_BACKLIGHT_FAILED; diff --git a/include/acpi/video.h b/include/acpi/video.h index ea4c7bbded4d..843ef1adfbfa 100644 --- a/include/acpi/video.h +++ b/include/acpi/video.h @@ -22,6 +22,7 @@ extern void acpi_video_unregister(void); extern void acpi_video_unregister_backlight(void); extern int acpi_video_get_edid(struct acpi_device *device, int type, int device_id, void **edid); +extern bool acpi_video_verify_backlight_support(void); #else static inline int acpi_video_register(void) { return 0; } static inline void acpi_video_unregister(void) { return; } @@ -31,6 +32,7 @@ static inline int acpi_video_get_edid(struct acpi_device *device, int type, { return -ENODEV; } +static inline bool acpi_video_verify_backlight_support(void) { return false; } #endif #endif -- cgit v1.2.3 From c0fb262bf226a5c943e4309662353d5fb905310a Mon Sep 17 00:00:00 2001 From: Arun Kumar K Date: Fri, 11 Jul 2014 08:03:59 +0900 Subject: clk: exynos5420: Add IDs for clocks used in PD mfc Adds IDs for MUX clocks to be used by power domain for MFC for doing re-parenting while pd on/off. Signed-off-by: Arun Kumar K Signed-off-by: Shaik Ameer Basha Acked-by: Tomasz Figa Signed-off-by: Kukjin Kim --- drivers/clk/samsung/clk-exynos5420.c | 6 ++++-- include/dt-bindings/clock/exynos5420.h | 2 ++ 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/clk/samsung/clk-exynos5420.c b/drivers/clk/samsung/clk-exynos5420.c index 9d7d7eed03fd..f74f882f7f29 100644 --- a/drivers/clk/samsung/clk-exynos5420.c +++ b/drivers/clk/samsung/clk-exynos5420.c @@ -631,7 +631,8 @@ static struct samsung_mux_clock exynos5x_mux_clks[] __initdata = { SRC_TOP4, 16, 1), MUX(0, "mout_user_aclk266", mout_user_aclk266_p, SRC_TOP4, 20, 1), MUX(0, "mout_user_aclk166", mout_user_aclk166_p, SRC_TOP4, 24, 1), - MUX(0, "mout_user_aclk333", mout_user_aclk333_p, SRC_TOP4, 28, 1), + MUX(CLK_MOUT_USER_ACLK333, "mout_user_aclk333", mout_user_aclk333_p, + SRC_TOP4, 28, 1), MUX(0, "mout_user_aclk400_disp1", mout_user_aclk400_disp1_p, SRC_TOP5, 0, 1), @@ -684,7 +685,8 @@ static struct samsung_mux_clock exynos5x_mux_clks[] __initdata = { SRC_TOP11, 12, 1), MUX(0, "mout_sw_aclk266", mout_sw_aclk266_p, SRC_TOP11, 20, 1), MUX(0, "mout_sw_aclk166", mout_sw_aclk166_p, SRC_TOP11, 24, 1), - MUX(0, "mout_sw_aclk333", mout_sw_aclk333_p, SRC_TOP11, 28, 1), + MUX(CLK_MOUT_SW_ACLK333, "mout_sw_aclk333", mout_sw_aclk333_p, + SRC_TOP11, 28, 1), MUX(0, "mout_sw_aclk400_disp1", mout_sw_aclk400_disp1_p, SRC_TOP12, 4, 1), diff --git a/include/dt-bindings/clock/exynos5420.h b/include/dt-bindings/clock/exynos5420.h index 97dcb89d37d3..3fc08ff24fa9 100644 --- a/include/dt-bindings/clock/exynos5420.h +++ b/include/dt-bindings/clock/exynos5420.h @@ -203,6 +203,8 @@ #define CLK_MOUT_G3D 641 #define CLK_MOUT_VPLL 642 #define CLK_MOUT_MAUDIO0 643 +#define CLK_MOUT_USER_ACLK333 644 +#define CLK_MOUT_SW_ACLK333 645 /* divider clocks */ #define CLK_DOUT_PIXEL 768 -- cgit v1.2.3 From 9ecf07a1d8f70f72ec99a0f102c8aa24609d84f4 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sat, 12 Jul 2014 22:36:44 +0200 Subject: neigh: sysctl - simplify address calculation of gc_* variables The code in neigh_sysctl_register() relies on a specific layout of struct neigh_table, namely that the 'gc_*' variables are directly following the 'parms' member in a specific order. The code, though, expresses this in the most ugly way. Get rid of the ugly casts and use the 'tbl' pointer to get a handle to the table. This way we can refer to the 'gc_*' variables directly. Similarly seen in the grsecurity patch, written by Brad Spengler. Signed-off-by: Mathias Krause Cc: Brad Spengler Signed-off-by: David S. Miller --- include/net/neighbour.h | 1 - net/core/neighbour.c | 9 +++++---- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 7277caf3743d..47f425464f84 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -203,7 +203,6 @@ struct neigh_table { void (*proxy_redo)(struct sk_buff *skb); char *id; struct neigh_parms parms; - /* HACK. gc_* should follow parms without a gap! */ int gc_interval; int gc_thresh1; int gc_thresh2; diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 32d872eec7f5..559890b0f0a2 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -3059,11 +3059,12 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0, sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL])); } else { + struct neigh_table *tbl = p->tbl; dev_name_source = "default"; - t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1); - t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1; - t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2; - t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = (int *)(p + 1) + 3; + t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = &tbl->gc_interval; + t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1; + t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2; + t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3; } if (handler) { -- cgit v1.2.3 From 046a619d8e9746fa4c0e29e8c6b78e16efc008a8 Mon Sep 17 00:00:00 2001 From: Jason Low Date: Mon, 14 Jul 2014 10:27:48 -0700 Subject: locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node() Currently, the per-cpu nodes structure for the cancellable MCS spinlock is named "optimistic_spin_queue". However, in a follow up patch in the series we will be introducing a new structure that serves as the new "handle" for the lock. It would make more sense if that structure is named "optimistic_spin_queue". Additionally, since the current use of the "optimistic_spin_queue" structure are "nodes", it might be better if we rename them to "node" anyway. This preparatory patch renames all current "optimistic_spin_queue" to "optimistic_spin_node". Signed-off-by: Jason Low Signed-off-by: Peter Zijlstra Cc: Scott Norton Cc: "Paul E. McKenney" Cc: Dave Chinner Cc: Waiman Long Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Andrew Morton Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Tim Chen Cc: Konrad Rzeszutek Wilk Cc: Aswin Chandramouleeswaran Cc: Linus Torvalds Cc: Chris Mason Cc: Heiko Carstens Cc: Josef Bacik Link: http://lkml.kernel.org/r/1405358872-3732-2-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar --- include/linux/mutex.h | 4 ++-- include/linux/rwsem.h | 4 ++-- kernel/locking/mcs_spinlock.c | 24 ++++++++++++------------ kernel/locking/mcs_spinlock.h | 8 ++++---- 4 files changed, 20 insertions(+), 20 deletions(-) (limited to 'include') diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 11692dea18aa..885f3f56a77f 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -46,7 +46,7 @@ * - detects multi-task circular deadlocks and prints out all affected * locks and tasks (and only those tasks) */ -struct optimistic_spin_queue; +struct optimistic_spin_node; struct mutex { /* 1: unlocked, 0: locked, negative: locked, possible waiters */ atomic_t count; @@ -56,7 +56,7 @@ struct mutex { struct task_struct *owner; #endif #ifdef CONFIG_MUTEX_SPIN_ON_OWNER - struct optimistic_spin_queue *osq; /* Spinner MCS lock */ + struct optimistic_spin_node *osq; /* Spinner MCS lock */ #endif #ifdef CONFIG_DEBUG_MUTEXES const char *name; diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 8d79708146aa..ba3f108ddea1 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -16,7 +16,7 @@ #include -struct optimistic_spin_queue; +struct optimistic_spin_node; struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK @@ -33,7 +33,7 @@ struct rw_semaphore { * if the owner is running on the cpu. */ struct task_struct *owner; - struct optimistic_spin_queue *osq; /* spinner MCS lock */ + struct optimistic_spin_node *osq; /* spinner MCS lock */ #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; diff --git a/kernel/locking/mcs_spinlock.c b/kernel/locking/mcs_spinlock.c index 838dc9e00669..e9866f70e828 100644 --- a/kernel/locking/mcs_spinlock.c +++ b/kernel/locking/mcs_spinlock.c @@ -14,18 +14,18 @@ * called from interrupt context and we have preemption disabled while * spinning. */ -static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_queue, osq_node); +static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node); /* * Get a stable @node->next pointer, either for unlock() or unqueue() purposes. * Can return NULL in case we were the last queued and we updated @lock instead. */ -static inline struct optimistic_spin_queue * -osq_wait_next(struct optimistic_spin_queue **lock, - struct optimistic_spin_queue *node, - struct optimistic_spin_queue *prev) +static inline struct optimistic_spin_node * +osq_wait_next(struct optimistic_spin_node **lock, + struct optimistic_spin_node *node, + struct optimistic_spin_node *prev) { - struct optimistic_spin_queue *next = NULL; + struct optimistic_spin_node *next = NULL; for (;;) { if (*lock == node && cmpxchg(lock, node, prev) == node) { @@ -59,10 +59,10 @@ osq_wait_next(struct optimistic_spin_queue **lock, return next; } -bool osq_lock(struct optimistic_spin_queue **lock) +bool osq_lock(struct optimistic_spin_node **lock) { - struct optimistic_spin_queue *node = this_cpu_ptr(&osq_node); - struct optimistic_spin_queue *prev, *next; + struct optimistic_spin_node *node = this_cpu_ptr(&osq_node); + struct optimistic_spin_node *prev, *next; node->locked = 0; node->next = NULL; @@ -149,10 +149,10 @@ unqueue: return false; } -void osq_unlock(struct optimistic_spin_queue **lock) +void osq_unlock(struct optimistic_spin_node **lock) { - struct optimistic_spin_queue *node = this_cpu_ptr(&osq_node); - struct optimistic_spin_queue *next; + struct optimistic_spin_node *node = this_cpu_ptr(&osq_node); + struct optimistic_spin_node *next; /* * Fast path for the uncontended case. diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index a2dbac4aca6b..c99dc0052f49 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -118,12 +118,12 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) * mutex_lock()/rwsem_down_{read,write}() etc. */ -struct optimistic_spin_queue { - struct optimistic_spin_queue *next, *prev; +struct optimistic_spin_node { + struct optimistic_spin_node *next, *prev; int locked; /* 1 if lock acquired */ }; -extern bool osq_lock(struct optimistic_spin_queue **lock); -extern void osq_unlock(struct optimistic_spin_queue **lock); +extern bool osq_lock(struct optimistic_spin_node **lock); +extern void osq_unlock(struct optimistic_spin_node **lock); #endif /* __LINUX_MCS_SPINLOCK_H */ -- cgit v1.2.3 From 90631822c5d307b5410500806e8ac3e63928aa3e Mon Sep 17 00:00:00 2001 From: Jason Low Date: Mon, 14 Jul 2014 10:27:49 -0700 Subject: locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead The cancellable MCS spinlock is currently used to queue threads that are doing optimistic spinning. It uses per-cpu nodes, where a thread obtaining the lock would access and queue the local node corresponding to the CPU that it's running on. Currently, the cancellable MCS lock is implemented by using pointers to these nodes. In this patch, instead of operating on pointers to the per-cpu nodes, we store the CPU numbers in which the per-cpu nodes correspond to in atomic_t. A similar concept is used with the qspinlock. By operating on the CPU # of the nodes using atomic_t instead of pointers to those nodes, this can reduce the overhead of the cancellable MCS spinlock by 32 bits (on 64 bit systems). Signed-off-by: Jason Low Signed-off-by: Peter Zijlstra Cc: Scott Norton Cc: "Paul E. McKenney" Cc: Dave Chinner Cc: Waiman Long Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Andrew Morton Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Tim Chen Cc: Konrad Rzeszutek Wilk Cc: Aswin Chandramouleeswaran Cc: Linus Torvalds Cc: Chris Mason Cc: Heiko Carstens Cc: Josef Bacik Link: http://lkml.kernel.org/r/1405358872-3732-3-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar --- include/linux/mutex.h | 4 ++-- include/linux/osq_lock.h | 19 ++++++++++++++++++ include/linux/rwsem.h | 7 +++---- kernel/locking/mcs_spinlock.c | 46 ++++++++++++++++++++++++++++++++++++------- kernel/locking/mcs_spinlock.h | 5 +++-- kernel/locking/mutex.c | 2 +- kernel/locking/rwsem-xadd.c | 2 +- 7 files changed, 68 insertions(+), 17 deletions(-) create mode 100644 include/linux/osq_lock.h (limited to 'include') diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 885f3f56a77f..42aa9b9ecd5f 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -17,6 +17,7 @@ #include #include #include +#include /* * Simple, straightforward mutexes with strict semantics: @@ -46,7 +47,6 @@ * - detects multi-task circular deadlocks and prints out all affected * locks and tasks (and only those tasks) */ -struct optimistic_spin_node; struct mutex { /* 1: unlocked, 0: locked, negative: locked, possible waiters */ atomic_t count; @@ -56,7 +56,7 @@ struct mutex { struct task_struct *owner; #endif #ifdef CONFIG_MUTEX_SPIN_ON_OWNER - struct optimistic_spin_node *osq; /* Spinner MCS lock */ + struct optimistic_spin_queue osq; /* Spinner MCS lock */ #endif #ifdef CONFIG_DEBUG_MUTEXES const char *name; diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h new file mode 100644 index 000000000000..b001682bf7cb --- /dev/null +++ b/include/linux/osq_lock.h @@ -0,0 +1,19 @@ +#ifndef __LINUX_OSQ_LOCK_H +#define __LINUX_OSQ_LOCK_H + +/* + * An MCS like lock especially tailored for optimistic spinning for sleeping + * lock implementations (mutex, rwsem, etc). + */ + +#define OSQ_UNLOCKED_VAL (0) + +struct optimistic_spin_queue { + /* + * Stores an encoded value of the CPU # of the tail node in the queue. + * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL. + */ + atomic_t tail; +}; + +#endif diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index ba3f108ddea1..9fdcdd03507d 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -13,10 +13,9 @@ #include #include #include - #include +#include -struct optimistic_spin_node; struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK @@ -33,7 +32,7 @@ struct rw_semaphore { * if the owner is running on the cpu. */ struct task_struct *owner; - struct optimistic_spin_node *osq; /* spinner MCS lock */ + struct optimistic_spin_queue osq; /* spinner MCS lock */ #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; @@ -70,7 +69,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ LIST_HEAD_INIT((name).wait_list), \ NULL, /* owner */ \ - NULL /* mcs lock */ \ + { ATOMIC_INIT(OSQ_UNLOCKED_VAL) } /* osq */ \ __RWSEM_DEP_MAP_INIT(name) } #else #define __RWSEM_INITIALIZER(name) \ diff --git a/kernel/locking/mcs_spinlock.c b/kernel/locking/mcs_spinlock.c index e9866f70e828..32fc16c0a545 100644 --- a/kernel/locking/mcs_spinlock.c +++ b/kernel/locking/mcs_spinlock.c @@ -16,19 +16,45 @@ */ static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node); +/* + * We use the value 0 to represent "no CPU", thus the encoded value + * will be the CPU number incremented by 1. + */ +static inline int encode_cpu(int cpu_nr) +{ + return cpu_nr + 1; +} + +static inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val) +{ + int cpu_nr = encoded_cpu_val - 1; + + return per_cpu_ptr(&osq_node, cpu_nr); +} + /* * Get a stable @node->next pointer, either for unlock() or unqueue() purposes. * Can return NULL in case we were the last queued and we updated @lock instead. */ static inline struct optimistic_spin_node * -osq_wait_next(struct optimistic_spin_node **lock, +osq_wait_next(struct optimistic_spin_queue *lock, struct optimistic_spin_node *node, struct optimistic_spin_node *prev) { struct optimistic_spin_node *next = NULL; + int curr = encode_cpu(smp_processor_id()); + int old; + + /* + * If there is a prev node in queue, then the 'old' value will be + * the prev node's CPU #, else it's set to OSQ_UNLOCKED_VAL since if + * we're currently last in queue, then the queue will then become empty. + */ + old = prev ? prev->cpu : OSQ_UNLOCKED_VAL; for (;;) { - if (*lock == node && cmpxchg(lock, node, prev) == node) { + if (atomic_read(&lock->tail) == curr && + atomic_cmpxchg(&lock->tail, curr, old) == curr) { /* * We were the last queued, we moved @lock back. @prev * will now observe @lock and will complete its @@ -59,18 +85,23 @@ osq_wait_next(struct optimistic_spin_node **lock, return next; } -bool osq_lock(struct optimistic_spin_node **lock) +bool osq_lock(struct optimistic_spin_queue *lock) { struct optimistic_spin_node *node = this_cpu_ptr(&osq_node); struct optimistic_spin_node *prev, *next; + int curr = encode_cpu(smp_processor_id()); + int old; node->locked = 0; node->next = NULL; + node->cpu = curr; - node->prev = prev = xchg(lock, node); - if (likely(prev == NULL)) + old = atomic_xchg(&lock->tail, curr); + if (old == OSQ_UNLOCKED_VAL) return true; + prev = decode_cpu(old); + node->prev = prev; ACCESS_ONCE(prev->next) = node; /* @@ -149,15 +180,16 @@ unqueue: return false; } -void osq_unlock(struct optimistic_spin_node **lock) +void osq_unlock(struct optimistic_spin_queue *lock) { struct optimistic_spin_node *node = this_cpu_ptr(&osq_node); struct optimistic_spin_node *next; + int curr = encode_cpu(smp_processor_id()); /* * Fast path for the uncontended case. */ - if (likely(cmpxchg(lock, node, NULL) == node)) + if (likely(atomic_cmpxchg(&lock->tail, curr, OSQ_UNLOCKED_VAL) == curr)) return; /* diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h index c99dc0052f49..74356dc0ce29 100644 --- a/kernel/locking/mcs_spinlock.h +++ b/kernel/locking/mcs_spinlock.h @@ -121,9 +121,10 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node) struct optimistic_spin_node { struct optimistic_spin_node *next, *prev; int locked; /* 1 if lock acquired */ + int cpu; /* encoded CPU # value */ }; -extern bool osq_lock(struct optimistic_spin_node **lock); -extern void osq_unlock(struct optimistic_spin_node **lock); +extern bool osq_lock(struct optimistic_spin_queue *lock); +extern void osq_unlock(struct optimistic_spin_queue *lock); #endif /* __LINUX_MCS_SPINLOCK_H */ diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index bc73d33c6760..d9b313906caa 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -60,7 +60,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) INIT_LIST_HEAD(&lock->wait_list); mutex_clear_owner(lock); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER - lock->osq = NULL; + atomic_set(&lock->osq.tail, OSQ_UNLOCKED_VAL); #endif debug_mutex_init(lock, name, key); diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index c40c7d28661d..b77a6230bbf6 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -84,7 +84,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, INIT_LIST_HEAD(&sem->wait_list); #ifdef CONFIG_SMP sem->owner = NULL; - sem->osq = NULL; + atomic_set(&sem->osq.tail, OSQ_UNLOCKED_VAL); #endif } -- cgit v1.2.3 From 4d9d951e6b5df85ccfca2c5bd8b4f5c71d256b65 Mon Sep 17 00:00:00 2001 From: Jason Low Date: Mon, 14 Jul 2014 10:27:50 -0700 Subject: locking/spinlocks/mcs: Introduce and use init macro and function for osq locks Currently, we initialize the osq lock by directly setting the lock's values. It would be preferable if we use an init macro to do the initialization like we do with other locks. This patch introduces and uses a macro and function for initializing the osq lock. Signed-off-by: Jason Low Signed-off-by: Peter Zijlstra Cc: Scott Norton Cc: "Paul E. McKenney" Cc: Dave Chinner Cc: Waiman Long Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Andrew Morton Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Tim Chen Cc: Konrad Rzeszutek Wilk Cc: Aswin Chandramouleeswaran Cc: Linus Torvalds Cc: Chris Mason Cc: Josef Bacik Link: http://lkml.kernel.org/r/1405358872-3732-4-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar --- include/linux/osq_lock.h | 8 ++++++++ include/linux/rwsem.h | 2 +- kernel/locking/mutex.c | 2 +- kernel/locking/rwsem-xadd.c | 2 +- 4 files changed, 11 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h index b001682bf7cb..90230d5811c5 100644 --- a/include/linux/osq_lock.h +++ b/include/linux/osq_lock.h @@ -16,4 +16,12 @@ struct optimistic_spin_queue { atomic_t tail; }; +/* Init macro and function. */ +#define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) } + +static inline void osq_lock_init(struct optimistic_spin_queue *lock) +{ + atomic_set(&lock->tail, OSQ_UNLOCKED_VAL); +} + #endif diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 9fdcdd03507d..25cd9aa2f3d7 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -69,7 +69,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ LIST_HEAD_INIT((name).wait_list), \ NULL, /* owner */ \ - { ATOMIC_INIT(OSQ_UNLOCKED_VAL) } /* osq */ \ + OSQ_LOCK_UNLOCKED /* osq */ \ __RWSEM_DEP_MAP_INIT(name) } #else #define __RWSEM_INITIALIZER(name) \ diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index d9b313906caa..acca2c1a3c5e 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -60,7 +60,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) INIT_LIST_HEAD(&lock->wait_list); mutex_clear_owner(lock); #ifdef CONFIG_MUTEX_SPIN_ON_OWNER - atomic_set(&lock->osq.tail, OSQ_UNLOCKED_VAL); + osq_lock_init(&lock->osq); #endif debug_mutex_init(lock, name, key); diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index b77a6230bbf6..7190592c2645 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -84,7 +84,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, INIT_LIST_HEAD(&sem->wait_list); #ifdef CONFIG_SMP sem->owner = NULL; - atomic_set(&sem->osq.tail, OSQ_UNLOCKED_VAL); + osq_lock_init(&sem->osq); #endif } -- cgit v1.2.3 From 13b9a962a2594ee880c5d50d7f70964da1d4fe5a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 16 Jul 2014 14:54:55 +0200 Subject: locking/rwsem: Rename 'activity' to 'count' There are two definitions of struct rw_semaphore, one in linux/rwsem.h and one in linux/rwsem-spinlock.h. For some reason they have different names for the initial field. This makes it impossible to use C99 named initialization for __RWSEM_INITIALIZER() -- or we have to duplicate that entire thing along with the structure definitions. The simpler patch is renaming the rwsem-spinlock variant to match the regular rwsem. This allows us to switch to C99 named initialization. Signed-off-by: Peter Zijlstra Cc: Linus Torvalds Link: http://lkml.kernel.org/n/tip-bmrZolsbGmautmzrerog27io@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/rwsem-spinlock.h | 8 ++++---- kernel/locking/rwsem-spinlock.c | 28 ++++++++++++++-------------- 2 files changed, 18 insertions(+), 18 deletions(-) (limited to 'include') diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h index d5b13bc07a0b..561e8615528d 100644 --- a/include/linux/rwsem-spinlock.h +++ b/include/linux/rwsem-spinlock.h @@ -15,13 +15,13 @@ #ifdef __KERNEL__ /* * the rw-semaphore definition - * - if activity is 0 then there are no active readers or writers - * - if activity is +ve then that is the number of active readers - * - if activity is -1 then there is one active writer + * - if count is 0 then there are no active readers or writers + * - if count is +ve then that is the number of active readers + * - if count is -1 then there is one active writer * - if wait_list is not empty, then there are processes waiting for the semaphore */ struct rw_semaphore { - __s32 activity; + __s32 count; raw_spinlock_t wait_lock; struct list_head wait_list; #ifdef CONFIG_DEBUG_LOCK_ALLOC diff --git a/kernel/locking/rwsem-spinlock.c b/kernel/locking/rwsem-spinlock.c index 9be8a9144978..2c93571162cb 100644 --- a/kernel/locking/rwsem-spinlock.c +++ b/kernel/locking/rwsem-spinlock.c @@ -26,7 +26,7 @@ int rwsem_is_locked(struct rw_semaphore *sem) unsigned long flags; if (raw_spin_trylock_irqsave(&sem->wait_lock, flags)) { - ret = (sem->activity != 0); + ret = (sem->count != 0); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); } return ret; @@ -46,7 +46,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, debug_check_no_locks_freed((void *)sem, sizeof(*sem)); lockdep_init_map(&sem->dep_map, name, key, 0); #endif - sem->activity = 0; + sem->count = 0; raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); } @@ -95,7 +95,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) waiter = list_entry(next, struct rwsem_waiter, list); } while (waiter->type != RWSEM_WAITING_FOR_WRITE); - sem->activity += woken; + sem->count += woken; out: return sem; @@ -126,9 +126,9 @@ void __sched __down_read(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - if (sem->activity >= 0 && list_empty(&sem->wait_list)) { + if (sem->count >= 0 && list_empty(&sem->wait_list)) { /* granted */ - sem->activity++; + sem->count++; raw_spin_unlock_irqrestore(&sem->wait_lock, flags); goto out; } @@ -170,9 +170,9 @@ int __down_read_trylock(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - if (sem->activity >= 0 && list_empty(&sem->wait_list)) { + if (sem->count >= 0 && list_empty(&sem->wait_list)) { /* granted */ - sem->activity++; + sem->count++; ret = 1; } @@ -206,7 +206,7 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) * itself into sleep and waiting for system woke it or someone * else in the head of the wait list up. */ - if (sem->activity == 0) + if (sem->count == 0) break; set_task_state(tsk, TASK_UNINTERRUPTIBLE); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); @@ -214,7 +214,7 @@ void __sched __down_write_nested(struct rw_semaphore *sem, int subclass) raw_spin_lock_irqsave(&sem->wait_lock, flags); } /* got the lock */ - sem->activity = -1; + sem->count = -1; list_del(&waiter.list); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); @@ -235,9 +235,9 @@ int __down_write_trylock(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - if (sem->activity == 0) { + if (sem->count == 0) { /* got the lock */ - sem->activity = -1; + sem->count = -1; ret = 1; } @@ -255,7 +255,7 @@ void __up_read(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - if (--sem->activity == 0 && !list_empty(&sem->wait_list)) + if (--sem->count == 0 && !list_empty(&sem->wait_list)) sem = __rwsem_wake_one_writer(sem); raw_spin_unlock_irqrestore(&sem->wait_lock, flags); @@ -270,7 +270,7 @@ void __up_write(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - sem->activity = 0; + sem->count = 0; if (!list_empty(&sem->wait_list)) sem = __rwsem_do_wake(sem, 1); @@ -287,7 +287,7 @@ void __downgrade_write(struct rw_semaphore *sem) raw_spin_lock_irqsave(&sem->wait_lock, flags); - sem->activity = 1; + sem->count = 1; if (!list_empty(&sem->wait_list)) sem = __rwsem_do_wake(sem, 0); -- cgit v1.2.3 From ce069fc920e5734558b3d9cbef1ab06cf01ee793 Mon Sep 17 00:00:00 2001 From: Jason Low Date: Mon, 14 Jul 2014 10:27:52 -0700 Subject: locking/rwsem: Reduce the size of struct rw_semaphore Recent optimistic spinning additions to rwsem provide significant performance benefits on many workloads on large machines. The cost of it was increasing the size of the rwsem structure by up to 128 bits. However, now that the previous patches in this series bring the overhead of struct optimistic_spin_queue to 32 bits, this patch reorders some fields in struct rw_semaphore such that we can reduce the overhead of the rwsem structure by 64 bits (on 64 bit systems). The extra overhead required for rwsem optimistic spinning would now be up to 8 additional bytes instead of up to 16 bytes. Additionally, the size of rwsem would now be more in line with mutexes. Signed-off-by: Jason Low Signed-off-by: Peter Zijlstra Cc: Scott Norton Cc: "Paul E. McKenney" Cc: Dave Chinner Cc: Waiman Long Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Andrew Morton Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Tim Chen Cc: Konrad Rzeszutek Wilk Cc: Aswin Chandramouleeswaran Cc: Linus Torvalds Cc: Chris Mason Cc: Josef Bacik Link: http://lkml.kernel.org/r/1405358872-3732-6-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar --- include/linux/rwsem.h | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 25cd9aa2f3d7..716807f0eb2d 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -24,15 +24,15 @@ struct rw_semaphore; /* All arch specific implementations share the same struct */ struct rw_semaphore { long count; - raw_spinlock_t wait_lock; struct list_head wait_list; + raw_spinlock_t wait_lock; #ifdef CONFIG_SMP + struct optimistic_spin_queue osq; /* spinner MCS lock */ /* * Write owner. Used as a speculative check to see * if the owner is running on the cpu. */ struct task_struct *owner; - struct optimistic_spin_queue osq; /* spinner MCS lock */ #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; @@ -64,21 +64,18 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) #endif #if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) -#define __RWSEM_INITIALIZER(name) \ - { RWSEM_UNLOCKED_VALUE, \ - __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ - LIST_HEAD_INIT((name).wait_list), \ - NULL, /* owner */ \ - OSQ_LOCK_UNLOCKED /* osq */ \ - __RWSEM_DEP_MAP_INIT(name) } +#define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL #else -#define __RWSEM_INITIALIZER(name) \ - { RWSEM_UNLOCKED_VALUE, \ - __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \ - LIST_HEAD_INIT((name).wait_list) \ - __RWSEM_DEP_MAP_INIT(name) } +#define __RWSEM_OPT_INIT(lockname) #endif +#define __RWSEM_INITIALIZER(name) \ + { .count = RWSEM_UNLOCKED_VALUE, \ + .wait_list = LIST_HEAD_INIT((name).wait_list), \ + .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(name.wait_lock) \ + __RWSEM_OPT_INIT(name) \ + __RWSEM_DEP_MAP_INIT(name) } + #define DECLARE_RWSEM(name) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name) -- cgit v1.2.3 From 5db6c6fefb1ca0e81e3bd6dd8998bf51c453d823 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Fri, 11 Jul 2014 14:00:06 -0700 Subject: locking/rwsem: Add CONFIG_RWSEM_SPIN_ON_OWNER Just like with mutexes (CONFIG_MUTEX_SPIN_ON_OWNER), encapsulate the dependencies for rwsem optimistic spinning. No logical changes here as it continues to depend on both SMP and the XADD algorithm variant. Signed-off-by: Davidlohr Bueso Acked-by: Jason Low [ Also make it depend on ARCH_SUPPORTS_ATOMIC_RMW. ] Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1405112406-13052-2-git-send-email-davidlohr@hp.com Cc: aswin@hp.com Cc: Chris Mason Cc: Davidlohr Bueso Cc: Josef Bacik Cc: Linus Torvalds Cc: Waiman Long Signed-off-by: Ingo Molnar Signed-off-by: Ingo Molnar --- include/linux/rwsem.h | 6 ++++-- kernel/Kconfig.locks | 4 ++++ kernel/locking/rwsem-xadd.c | 4 ++-- kernel/locking/rwsem.c | 2 +- 4 files changed, 11 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 716807f0eb2d..035d3c57fc8a 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -14,7 +14,9 @@ #include #include #include +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER #include +#endif struct rw_semaphore; @@ -26,7 +28,7 @@ struct rw_semaphore { long count; struct list_head wait_list; raw_spinlock_t wait_lock; -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER struct optimistic_spin_queue osq; /* spinner MCS lock */ /* * Write owner. Used as a speculative check to see @@ -63,7 +65,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem) # define __RWSEM_DEP_MAP_INIT(lockname) #endif -#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK) +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER #define __RWSEM_OPT_INIT(lockname) , .osq = OSQ_LOCK_UNLOCKED, .owner = NULL #else #define __RWSEM_OPT_INIT(lockname) diff --git a/kernel/Kconfig.locks b/kernel/Kconfig.locks index 81907941d921..76768ee812b2 100644 --- a/kernel/Kconfig.locks +++ b/kernel/Kconfig.locks @@ -227,6 +227,10 @@ config MUTEX_SPIN_ON_OWNER def_bool y depends on SMP && !DEBUG_MUTEXES && ARCH_SUPPORTS_ATOMIC_RMW +config RWSEM_SPIN_ON_OWNER + def_bool y + depends on SMP && RWSEM_XCHGADD_ALGORITHM && ARCH_SUPPORTS_ATOMIC_RMW + config ARCH_USE_QUEUE_RWLOCK bool diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 7190592c2645..a2391ac135c8 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -82,7 +82,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, sem->count = RWSEM_UNLOCKED_VALUE; raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER sem->owner = NULL; osq_lock_init(&sem->osq); #endif @@ -262,7 +262,7 @@ static inline bool rwsem_try_write_lock(long count, struct rw_semaphore *sem) return false; } -#ifdef CONFIG_SMP +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* * Try to acquire write lock before the writer has been put on wait queue. */ diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 42f806de49d4..e2d3bc7f03b4 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -12,7 +12,7 @@ #include -#if defined(CONFIG_SMP) && defined(CONFIG_RWSEM_XCHGADD_ALGORITHM) +#ifdef CONFIG_RWSEM_SPIN_ON_OWNER static inline void rwsem_set_owner(struct rw_semaphore *sem) { sem->owner = current; -- cgit v1.2.3 From 2b1987a9f1e6250c962ca13820d3c69817879266 Mon Sep 17 00:00:00 2001 From: Brian W Hart Date: Fri, 27 Jun 2014 16:09:39 -0500 Subject: cpufreq: make table sentinel macros unsigned to match use MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 5eeaf1f18973 (cpufreq: Fix build error on some platforms that use cpufreq_for_each_*) moved function cpufreq_next_valid() to a public header. Warnings are now generated when objects including that header are built with -Wsign-compare (as an out-of-tree module might be): .../include/linux/cpufreq.h: In function ‘cpufreq_next_valid’: .../include/linux/cpufreq.h:519:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ((*pos)->frequency != CPUFREQ_TABLE_END) ^ .../include/linux/cpufreq.h:520:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID) ^ Constants CPUFREQ_ENTRY_INVALID and CPUFREQ_TABLE_END are signed, but are used with unsigned member 'frequency' of cpufreq_frequency_table. Update the macro definitions to be explicitly unsigned to match their use. This also corrects potentially wrong behavior of clk_rate_table_iter() if unsigned long is wider than usigned int. Fixes: 5eeaf1f18973 (cpufreq: Fix build error on some platforms that use cpufreq_for_each_*) Signed-off-by: Brian W Hart Reviewed-by: Simon Horman Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index ec4112d257bc..8f8ae95c6e27 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -482,8 +482,8 @@ extern struct cpufreq_governor cpufreq_gov_conservative; *********************************************************************/ /* Special Values of .frequency field */ -#define CPUFREQ_ENTRY_INVALID ~0 -#define CPUFREQ_TABLE_END ~1 +#define CPUFREQ_ENTRY_INVALID ~0u +#define CPUFREQ_TABLE_END ~1u /* Special Values of .flags field */ #define CPUFREQ_BOOST_FREQ (1 << 0) -- cgit v1.2.3