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2011-01-13kernel: clean up USE_GENERIC_SMP_HELPERSAmerigo Wang1-19/+0
For arch which needs USE_GENERIC_SMP_HELPERS, it has to select USE_GENERIC_SMP_HELPERS, rather than leaving a choice to user, since they don't provide their own implementions. Also, move on_each_cpu() to kernel/smp.c, it is strange to put it in kernel/softirq.c. For arch which doesn't use USE_GENERIC_SMP_HELPERS, e.g. blackfin, only on_each_cpu() is compiled. Signed-off-by: Amerigo Wang <amwang@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-07Merge branch 'for-2.6.38' of ↵Linus Torvalds1-21/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits) gameport: use this_cpu_read instead of lookup x86: udelay: Use this_cpu_read to avoid address calculation x86: Use this_cpu_inc_return for nmi counter x86: Replace uses of current_cpu_data with this_cpu ops x86: Use this_cpu_ops to optimize code vmstat: User per cpu atomics to avoid interrupt disable / enable irq_work: Use per cpu atomics instead of regular atomics cpuops: Use cmpxchg for xchg to avoid lock semantics x86: this_cpu_cmpxchg and this_cpu_xchg operations percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support percpu,x86: relocate this_cpu_add_return() and friends connector: Use this_cpu operations xen: Use this_cpu_inc_return taskstats: Use this_cpu_ops random: Use this_cpu_inc_return fs: Use this_cpu_inc_return in buffer.c highmem: Use this_cpu_xx_return() operations vmstat: Use this_cpu_inc_return for vm statistics x86: Support for this_cpu_add, sub, dec, inc_return percpu: Generic support for this_cpu_add, sub, dec, inc_return ... Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c} as per Tejun.
2011-01-07sched: Constify function scope static struct sched_param usagePeter Zijlstra1-1/+1
Function-scope statics are discouraged because they are easily overlooked and can cause subtle bugs/races due to their global (non-SMP safe) nature. Linus noticed that we did this for sched_param - at minimum make the const. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: Message-ID: <AANLkTinotRxScOHEb0HgFgSpGPkq_6jKTv5CfvnQM=ee@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-12-17core: Replace __get_cpu_var with __this_cpu_read if not used for an address.Christoph Lameter1-21/+21
__get_cpu_var() can be replaced with this_cpu_read and will then use a single read instruction with implied address calculation to access the correct per cpu instance. However, the address of a per cpu variable passed to __this_cpu_read() cannot be determined (since it's an implied address conversion through segment prefixes). Therefore apply this only to uses of __get_cpu_var where the address of the variable is not used. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hughd@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2010-11-18Merge commit 'v2.6.37-rc2' into sched/coreIngo Molnar1-8/+10
Merge reason: Move to a .37-rc base. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-27Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds1-7/+9
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits) perf python scripting: Add futex-contention script perf python scripting: Fixup cut'n'paste error in sctop script perf scripting: Shut up 'perf record' final status perf record: Remove newline character from perror() argument perf python scripting: Support fedora 11 (audit 1.7.17) perf python scripting: Improve the syscalls-by-pid script perf python scripting: print the syscall name on sctop perf python scripting: Improve the syscalls-counts script perf python scripting: Improve the failed-syscalls-by-pid script kprobes: Remove redundant text_mutex lock in optimize x86/oprofile: Fix uninitialized variable use in debug printk tracing: Fix 'faild' -> 'failed' typo perf probe: Fix format specified for Dwarf_Off parameter perf trace: Fix detection of script extension perf trace: Use $PERF_EXEC_PATH in canned report scripts perf tools: Document event modifiers perf tools: Remove direct slang.h include perf_events: Fix for transaction recovery in group_sched_in() perf_events: Revert: Fix transaction recovery in group_sched_in() perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations ...
2010-10-23Merge branch 'perf/core' of ↵Ingo Molnar1-7/+9
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent
2010-10-23sched: Make sched_param argument static in sched_setscheduler() callersKOSAKI Motohiro1-1/+3
Andrew Morton pointed out almost all sched_setscheduler() callers are using fixed parameters and can be converted to static. It reduces runtime memory use a little. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: James Morris <jmorris@namei.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-23Merge branches 'softirq-for-linus', 'x86-debug-for-linus', ↵Linus Torvalds1-1/+1
'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: softirqs: Make wakeup_softirqd static * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, asm: Restore parentheses around one pushl_cfi argument x86, asm: Fix ancient-GAS workaround x86, asm: Fix CFI macro invocations to deal with shortcomings in gas * 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA * 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: HPET force enable for CX700 / VIA Epia LT * 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, setup: Use string copy operation to optimze copy in kernel compression * 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, UV: Use allocated buffer in tlb_uv.c:tunables_read() * 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
2010-10-21Merge branch 'irq-core-for-linus' of ↵Linus Torvalds1-6/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (96 commits) apic, x86: Use BIOS settings for IBS and MCE threshold interrupt LVT offsets apic, x86: Check if EILVT APIC registers are available (AMD only) x86: ioapic: Call free_irte only if interrupt remapping enabled arm: Use ARCH_IRQ_INIT_FLAGS genirq, ARM: Fix boot on ARM platforms genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build x86: Switch sparse_irq allocations to GFP_KERNEL genirq: Switch sparse_irq allocator to GFP_KERNEL genirq: Make sparse_lock a mutex x86: lguest: Use new irq allocator genirq: Remove the now unused sparse irq leftovers genirq: Sanitize dynamic irq handling genirq: Remove arch_init_chip_data() x86: xen: Sanitise sparse_irq handling x86: Use sane enumeration x86: uv: Clean up the direct access to irq_desc x86: Make io_apic.c local functions static genirq: Remove irq_2_iommu x86: Speed up the irq_remapped check in hot pathes intr_remap: Simplify the code further ... Fix up trivial conflicts in arch/x86/Kconfig
2010-10-21tracing: Cleanup the convoluted softirq tracepointsThomas Gleixner1-7/+9
With the addition of trace_softirq_raise() the softirq tracepoint got even more convoluted. Why the tracepoints take two pointers to assign an integer is beyond my comprehension. But adding an extra case which treats the first pointer as an unsigned long when the second pointer is NULL including the back and forth type casting is just horrible. Convert the softirq tracepoints to take a single unsigned int argument for the softirq vector number and fix the call sites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1010191428560.6815@localhost6.localdomain6> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: mathieu.desnoyers@efficios.com Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org>
2010-10-18sched: Call tick_check_idle before __irq_enterVenkatesh Pallipadi1-3/+9
When CPU is idle and on first interrupt, irq_enter calls tick_check_idle() to notify interruption from idle. But, there is a problem if this call is done after __irq_enter, as all routines in __irq_enter may find stale time due to yet to be done tick_check_idle. Specifically, trace calls in __irq_enter when they use global clock and also account_system_vtime change in this patch as it wants to use sched_clock_cpu() to do proper irq timing. But, tick_check_idle was moved after __irq_enter intentionally to prevent problem of unneeded ksoftirqd wakeups by the commit ee5f80a: irq: call __irq_enter() before calling the tick_idle_check Impact: avoid spurious ksoftirqd wakeups Moving tick_check_idle() before __irq_enter and wrapping it with local_bh_enable/disable would solve both the problems. Fixed-by: Yong Zhang <yong.zhang0@gmail.com> Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-9-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Add a PF flag for ksoftirqd identificationVenkatesh Pallipadi1-0/+1
To account softirq time cleanly in scheduler, we need to identify whether softirq is invoked in ksoftirqd context or softirq at hardirq tail context. Add PF_KSOFTIRQD for that purpose. As all PF flag bits are currently taken, create space by moving one of the infrequently used bits (PF_THREAD_BOUND) down in task_struct to be along with some other state fields. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-4-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-18sched: Fix softirq time accountingVenkatesh Pallipadi1-17/+34
Peter Zijlstra found a bug in the way softirq time is accounted in VIRT_CPU_ACCOUNTING on this thread: http://lkml.indiana.edu/hypermail//linux/kernel/1009.2/01366.html The problem is, softirq processing uses local_bh_disable internally. There is no way, later in the flow, to differentiate between whether softirq is being processed or is it just that bh has been disabled. So, a hardirq when bh is disabled results in time being wrongly accounted as softirq. Looking at the code a bit more, the problem exists in !VIRT_CPU_ACCOUNTING as well. As account_system_time() in normal tick based accouting also uses softirq_count, which will be set even when not in softirq with bh disabled. Peter also suggested solution of using 2*SOFTIRQ_OFFSET as irq count for local_bh_{disable,enable} and using just SOFTIRQ_OFFSET while softirq processing. The patch below does that and adds API in_serving_softirq() which returns whether we are currently processing softirq or not. Also changes one of the usages of softirq_count in net/sched/cls_cgroup.c to in_serving_softirq. Looks like many usages of in_softirq really want in_serving_softirq. Those changes can be made individually on a case by case basis. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-2-git-send-email-venki@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Remove arch_init_chip_data()Thomas Gleixner1-5/+0
This function should have not been there in the first place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-10-12genirq: Query arch for number of early descriptorsThomas Gleixner1-1/+3
sparse irq sets up NR_IRQS_LEGACY irq descriptors and archs then go ahead and allocate more. Use the unused return value of arch_probe_nr_irqs() to let the architecture return the number of early allocations. Fix up all users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@elte.hu>
2010-09-22softirqs: Make wakeup_softirqd staticThomas Gleixner1-1/+1
No users outside of kernel/softirq.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-06-04kernel/: fix BUG_ON checks for cpu notifier callbacks direct callAkinobu Mita1-1/+1
The commit 80b5184cc537718122e036afe7e62d202b70d077 ("kernel/: convert cpu notifier to return encapsulate errno value") changed the return value of cpu notifier callbacks. Those callbacks don't return NOTIFY_BAD on failures anymore. But there are a few callbacks which are called directly at init time and checking the return value. I forgot to change BUG_ON checking by the direct callers in the commit. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27kernel/: convert cpu notifier to return encapsulate errno valueAkinobu Mita1-1/+1
By the previous modification, the cpu notifier can return encapsulate errno value. This converts the cpu notifiers for kernel/*.c Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-10rcu: refactor RCU's context-switch handlingPaul E. McKenney1-1/+1
The addition of preemptible RCU to treercu resulted in a bit of confusion and inefficiency surrounding the handling of context switches for RCU-sched and for RCU-preempt. For RCU-sched, a context switch is a quiescent state, pure and simple, just like it always has been. For RCU-preempt, a context switch is in no way a quiescent state, but special handling is required when a task blocks in an RCU read-side critical section. However, the callout from the scheduler and the outer loop in ksoftirqd still calls something named rcu_sched_qs(), whose name is no longer accurate. Furthermore, when rcu_check_callbacks() notes an RCU-sched quiescent state, it ends up unnecessarily (though harmlessly, aside from the performance hit) enqueuing the current task if it happens to be running in an RCU-preempt read-side critical section. This not only increases the maximum latency of scheduler_tick(), it also needlessly increases the overhead of the next outermost rcu_read_unlock() invocation. This patch addresses this situation by separating the notion of RCU's context-switch handling from that of RCU-sched's quiescent states. The context-switch handling is covered by rcu_note_context_switch() in general and by rcu_preempt_note_context_switch() for preemptible RCU. This permits rcu_sched_qs() to handle quiescent states and only quiescent states. It also reduces the maximum latency of scheduler_tick(), though probably by much less than a microsecond. Finally, it means that tasks within preemptible-RCU read-side critical sections avoid incurring the overhead of queuing unless there really is a context switch. Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org>
2010-02-03hrtimer, softirq: Fix hrtimer->softirq trampolinePeter Zijlstra1-10/+5
hrtimers callbacks are always done from hardirq context, either the jiffy tick interrupt or the hrtimer device interrupt. [ there is currently one exception that can still call a hrtimer callback from softirq, but even in that case this will still work correctly. ] Reported-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Yury Polyanskiy <ypolyans@princeton.edu> Tested-by: Wei Yongjun <yjwei@cn.fujitsu.com> Acked-by: David S. Miller <davem@davemloft.net> LKML-Reference: <1265120401.24455.306.camel@laptop> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-12-14Merge branch 'for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits) m68k: rename global variable vmalloc_end to m68k_vmalloc_end percpu: add missing per_cpu_ptr_to_phys() definition for UP percpu: Fix kdump failure if booted with percpu_alloc=page percpu: make misc percpu symbols unique percpu: make percpu symbols in ia64 unique percpu: make percpu symbols in powerpc unique percpu: make percpu symbols in x86 unique percpu: make percpu symbols in xen unique percpu: make percpu symbols in cpufreq unique percpu: make percpu symbols in oprofile unique percpu: make percpu symbols in tracer unique percpu: make percpu symbols under kernel/ and mm/ unique percpu: remove some sparse warnings percpu: make alloc_percpu() handle array types vmalloc: fix use of non-existent percpu variable in put_cpu_var() this_cpu: Use this_cpu_xx in trace_functions_graph.c this_cpu: Use this_cpu_xx for ftrace this_cpu: Use this_cpu_xx in nmi handling this_cpu: Use this_cpu operations in RCU this_cpu: Use this_cpu ops for VM statistics ... Fix up trivial (famous last words) global per-cpu naming conflicts in arch/x86/kvm/svm.c mm/slab.c
2009-11-02rcu: Cleanup: balance rcu_irq_enter()/rcu_irq_exit() callsLai Jiangshan1-1/+1
Currently, rcu_irq_exit() is invoked only for CONFIG_NO_HZ, while rcu_irq_enter() is invoked unconditionally. This patch moves rcu_irq_exit() out from under CONFIG_NO_HZ so that the calls are balanced. This patch has no effect on the behavior of the kernel because both rcu_irq_enter() and rcu_irq_exit() are empty for !CONFIG_NO_HZ, but the code is easier to understand if the calls are obviously balanced in all cases. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12567428891605-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-29percpu: make percpu symbols under kernel/ and mm/ uniqueTejun Heo1-2/+2
This patch updates percpu related symbols under kernel/ and mm/ such that percpu symbols are unique and don't clash with local symbols. This serves two purposes of decreasing the possibility of global percpu symbol collision and allowing dropping per_cpu__ prefix from percpu symbols. * kernel/lockdep.c: s/lock_stats/cpu_lock_stats/ * kernel/sched.c: s/init_rq_rt/init_rt_rq_var/ (any better idea?) s/sched_group_cpus/sched_groups/ * kernel/softirq.c: s/ksoftirqd/run_ksoftirqd/a * kernel/softlockup.c: s/(*)_timestamp/softlockup_\1_ts/ s/watchdog_task/softlockup_watchdog/ s/timestamp/ts/ for local variables * kernel/time/timer_stats: s/lookup_lock/tstats_lookup_lock/ * mm/slab.c: s/reap_work/slab_reap_work/ s/reap_node/slab_reap_node/ * mm/vmstat.c: local variable changed to avoid collision with vmstat_work Partly based on Rusty Russell's "alloc_percpu: rename percpu vars which cause name clashes" patch. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: (slab/vmstat) Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de>
2009-09-17softirq: add BLOCK_IOPOLL to softirq_to_nameLi Zefan1-1/+1
With BLOCK_IOPOLL_SOFTIRQ added, softirq_to_name[] and show_softirq_name() needs to be updated. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4AB20398.8070209@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-08-23rcu: Renamings to increase RCU clarityPaul E. McKenney1-2/+2
Make RCU-sched, RCU-bh, and RCU-preempt be underlying implementations, with "RCU" defined in terms of one of the three. Update the outdated rcu_qsctr_inc() names, as these functions no longer increment anything. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746132696-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-22softirq: introduce tasklet_hrtimer infrastructurePeter Zijlstra1-1/+63
commit ca109491f (hrtimer: removing all ur callback modes) moved all hrtimer callbacks into hard interrupt context when high resolution timers are active. That breaks code which relied on the assumption that the callback happens in softirq context. Provide a generic infrastructure which combines tasklets and hrtimers together to provide an in-softirq hrtimer experience. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: torvalds@linux-foundation.org Cc: kaber@trash.net Cc: David Miller <davem@davemloft.net> LKML-Reference: <1248265724.27058.1366.camel@twins> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-06-18softirq: introduce statistics for softirqKeika Kobayashi1-0/+1
Statistics for softirq doesn't exist. It will be helpful like statistics for interrupts. This patch introduces counting the number of softirq, which will be exported in /proc/softirqs. When softirq handler consumes much CPU time, /proc/stat is like the following. $ while :; do cat /proc/stat | head -n1 ; sleep 10 ; done cpu 88 0 408 739665 583 28 2 0 0 cpu 450 0 1090 740970 594 28 1294 0 0 ^^^^ softirq In such a situation, /proc/softirqs shows us which softirq handler is invoked. We can see the increase rate of softirqs. <before> $ cat /proc/softirqs CPU0 CPU1 CPU2 CPU3 HI 0 0 0 0 TIMER 462850 462805 462782 462718 NET_TX 0 0 0 365 NET_RX 2472 2 2 40 BLOCK 0 0 381 1164 TASKLET 0 0 0 224 SCHED 462654 462689 462698 462427 RCU 3046 2423 3367 3173 <after> $ cat /proc/softirqs CPU0 CPU1 CPU2 CPU3 HI 0 0 0 0 TIMER 463361 465077 465056 464991 NET_TX 53 0 1 365 NET_RX 3757 2 2 40 BLOCK 0 0 398 1170 TASKLET 0 0 0 224 SCHED 463074 464318 464612 463330 RCU 3505 2948 3947 3673 When CPU TIME of softirq is high, the rates of increase is the following. TIMER : 220/sec : CPU1-3 NET_TX : 5/sec : CPU0 NET_RX : 120/sec : CPU0 SCHED : 40-200/sec : all CPU RCU : 45-58/sec : all CPU The rates of increase in an idle mode is the following. TIMER : 250/sec SCHED : 250/sec RCU : 2/sec It seems many softirqs for receiving packets and rcu are invoked. This gives us help for checking system. Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> Reviewed-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-13tasklets: new tasklet scheduling functionVegard Nossum1-0/+11
Rationale: kmemcheck needs to be able to schedule a tasklet without touching any dynamically allocated memory _at_ _all_ (since that would lead to a recursive page fault). This tasklet is used for writing the error reports to the kernel log. The new scheduling function avoids touching any other tasklets by inserting the new tasklist as the head of the "tasklet_hi" list instead of on the tail. Also don't wake up the softirq thread lest the scheduler access some tracked memory and we go down with a recursive page fault. In this case, we'd better just wait for the maximum time of 1/HZ for the message to appear. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-10Merge branch 'tracing-for-linus' of ↵Linus Torvalds1-4/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (244 commits) Revert "x86, bts: reenable ptrace branch trace support" tracing: do not translate event helper macros in print format ftrace/documentation: fix typo in function grapher name tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK tracing: add protection around module events unload tracing: add trace_seq_vprint interface tracing: fix the block trace points print size tracing/events: convert block trace points to TRACE_EVENT() ring-buffer: fix ret in rb_add_time_stamp ring-buffer: pass in lockdep class key for reader_lock tracing: add annotation to what type of stack trace is recorded tracing: fix multiple use of __print_flags and __print_symbolic tracing/events: fix output format of user stack tracing/events: fix output format of kernel stack tracing/trace_stack: fix the number of entries in the header ring-buffer: discard timestamps that are at the start of the buffer ring-buffer: try to discard unneeded timestamps ring-buffer: fix bug in ring_buffer_discard_commit ftrace: do not profile functions when disabled tracing: make trace pipe recognize latency format flag ...
2009-05-07Merge branch 'linus' into tracing/coreIngo Molnar1-2/+2
Merge reason: tracing/core was on a .30-rc1 base and was missing out on on a handful of tracing fixes present in .30-rc5-almost. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-29tracing: fix build failure on s390Heiko Carstens1-0/+2
"tracing: create automated trace defines" causes this compile error on s390, as reported by Sachin Sant against linux-next: kernel/built-in.o: In function `__do_softirq': (.text+0x1c680): undefined reference to `__tracepoint_softirq_entry' This happens because the definitions of the softirq tracepoints were moved from kernel/softirq.c to kernel/irq/handle.c. Since s390 doesn't support generic hardirqs handle.c doesn't get compiled and the definitions are missing. So move the tracepoints to softirq.c again. [ Impact: fix build failure on s390 ] Reported-by: Sachin Sant <sachinp@in.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: fweisbec@gmail.com LKML-Reference: <20090429135139.5fac79b8@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28x86/irq: change irq_desc_alloc() to take node instead of cpuYinghai Lu1-1/+1
This simplifies the node awareness of the code. All our allocators only deal with a NUMA node ID locality not with CPU ids anyway - so there's no need to maintain (and transform) a CPU id all across the IRq layer. v2: keep move_irq_desc related [ Impact: cleanup, prepare IRQ code to be NUMA-aware ] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> LKML-Reference: <49F65536.2020300@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-17kernel/softirq.c: fix sparse warningH Hartley Sweeten1-2/+2
Fix sparse warning in kernel/softirq.c. warning: do-while statement is not a compound statement Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> LKML-Reference: <BD79186B4FD85F4B8E60E381CAEE1909015F9033@mi8nycmail19.Mi8.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-14tracing/events: move trace point headers into include/trace/eventsSteven Rostedt1-1/+1
Impact: clean up Create a sub directory in include/trace called events to keep the trace point headers in their own separate directory. Only headers that declare trace points should be defined in this directory. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-14tracing: create automated trace definesSteven Rostedt1-3/+0
This patch lowers the number of places a developer must modify to add new tracepoints. The current method to add a new tracepoint into an existing system is to write the trace point macro in the trace header with one of the macros TRACE_EVENT, TRACE_FORMAT or DECLARE_TRACE, then they must add the same named item into the C file with the macro DEFINE_TRACE(name) and then add the trace point. This change cuts out the needing to add the DEFINE_TRACE(name). Every file that uses the tracepoint must still include the trace/<type>.h file, but the one C file must also add a define before the including of that file. #define CREATE_TRACE_POINTS #include <trace/mytrace.h> This will cause the trace/mytrace.h file to also produce the C code necessary to implement the trace point. Note, if more than one trace/<type>.h is used to create the C code it is best to list them all together. #define CREATE_TRACE_POINTS #include <trace/foo.h> #include <trace/bar.h> #include <trace/fido.h> Thanks to Mathieu Desnoyers and Christoph Hellwig for coming up with the cleaner solution of the define above the includes over my first design to have the C code include a "special" header. This patch converts sched, irq and lockdep and skb to use this new method. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Zhao Lei <zhaolei@cn.fujitsu.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-04-06Merge branch 'locking-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: add stack dumps to asserts hrtimer: fix rq->lock inversion (again)
2009-04-05Merge branch 'tracing-for-linus' of ↵Linus Torvalds1-3/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits) tracing, net: fix net tree and tracing tree merge interaction tracing, powerpc: fix powerpc tree and tracing tree interaction ring-buffer: do not remove reader page from list on ring buffer free function-graph: allow unregistering twice trace: make argument 'mem' of trace_seq_putmem() const tracing: add missing 'extern' keywords to trace_output.h tracing: provide trace_seq_reserve() blktrace: print out BLK_TN_MESSAGE properly blktrace: extract duplidate code blktrace: fix memory leak when freeing struct blk_io_trace blktrace: fix blk_probes_ref chaos blktrace: make classic output more classic blktrace: fix off-by-one bug blktrace: fix the original blktrace blktrace: fix a race when creating blk_tree_root in debugfs blktrace: fix timestamp in binary output tracing, Text Edit Lock: cleanup tracing: filter fix for TRACE_EVENT_FORMAT events ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release() x86: kretprobe-booster interrupt emulation code fix ... Fix up trivial conflicts in arch/parisc/include/asm/ftrace.h include/linux/memory.h kernel/extable.c kernel/module.c
2009-04-03Merge branch 'ipi-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: s390: remove arch specific smp_send_stop() panic: clean up kernel/panic.c panic, smp: provide smp_send_stop() wrapper on UP too panic: decrease oops_in_progress only after having done the panic generic-ipi: eliminate WARN_ON()s during oops/panic generic-ipi: cleanups generic-ipi: remove CSD_FLAG_WAIT generic-ipi: remove kmalloc() generic IPI: simplify barriers and locking
2009-03-31hrtimer: fix rq->lock inversion (again)Peter Zijlstra1-1/+1
It appears I inadvertly introduced rq->lock recursion to the hrtimer_start() path when I delegated running already expired timers to softirq context. This patch fixes it by introducing a __hrtimer_start_range_ns() method that will not use raise_softirq_irqoff() but __raise_softirq_irqoff() which avoids the wakeup. It then also changes schedule() to check for pending softirqs and do the wakeup then, I'm not quite sure I like this last bit, nor am I convinced its really needed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org LKML-Reference: <20090313112301.096138802@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-31Merge branch 'linus' into locking-for-linusIngo Molnar1-0/+5
Conflicts: lib/Kconfig.debug
2009-03-27Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2Ingo Molnar1-0/+5
Conflicts: arch/parisc/kernel/irq.c arch/x86/include/asm/fixmap_64.h arch/x86/include/asm/setup.h kernel/irq/handle.c Semantic merge: arch/x86/include/asm/fixmap.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-13Merge branch 'x86/core' into core/ipiIngo Molnar1-0/+5
2009-03-13softirq: no need to have SOFTIRQ in softirq nameSteven Rostedt1-3/+2
Impact: clean up It is redundant to have 'SOFTIRQ' in the softirq names. Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12tracing: tracepoints for softirq entry/exit - tracepointsJason Baron1-1/+6
Introduce softirq entry/exit tracepoints. These are useful for augmenting existing tracers, and to figure out softirq frequencies and timings. [ s/irq_softirq_/softirq_/ for trace point names and Fixed printf format in TRACE_FORMAT macro - Steven Rostedt ] LKML-Reference: <20090312183603.GC3352@redhat.com> Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-12tracing: tracepoints for softirq entry/exit - add softirq-to-name arrayJason Baron1-1/+8
Create a 'softirq_to_name' array, which is indexed by softirq #, so that we can easily convert between the softirq index # and its name, in order to get more meaningful output messages. LKML-Reference: <20090312183336.GB3352@redhat.com> Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-03-13Merge branch 'linus' into core/ipiIngo Molnar1-0/+1
2009-03-13Merge branch 'core/locking' into tracing/ftraceIngo Molnar1-2/+2
2009-03-13locking: rename trace_softirq_[enter|exit] => lockdep_softirq_[enter|exit]Ingo Molnar1-2/+2
Impact: cleanup The naming clashes with upcoming softirq tracepoints, so rename the APIs to lockdep_*(). Requested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-10Merge branches 'tracing/doc', 'tracing/ftrace', 'tracing/printk' and 'linus' ↵Ingo Molnar1-0/+1
into tracing/core
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