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2013-06-27sched: Change cfs_rq load avg to unsigned longAlex Shi3-8/+5
Since the 'u64 runnable_load_avg, blocked_load_avg' in cfs_rq struct are smaller than 'unsigned long' cfs_rq->load.weight. We don't need u64 vaiables to describe them. unsigned long is more efficient and convenience. Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Paul Turner <pjt@google.com> Tested-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-10-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Consider runnable load average in move_tasks()Alex Shi1-9/+9
Aside from using runnable load average in background, move_tasks is also the key function in load balance. We need consider the runnable load average in it in order to make it an apple to apple load comparison. Morten had caught a div u64 bug on ARM, thanks! Thanks-to: Morten Rasmussen <morten.rasmussen@arm.com> Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-8-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Compute runnable load avg in cpu_load and cpu_avg_load_per_taskAlex Shi2-4/+18
They are the base values in load balance, update them with rq runnable load average, then the load balance will consider runnable load avg naturally. We also try to include the blocked_load_avg as cpu load in balancing, but that cause kbuild performance drop 6% on every Intel machine, and aim7/oltp drop on some of 4 CPU sockets machines. Or only add blocked_load_avg into get_rq_runable_load, hackbench still drop a little on NHM EX. Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-7-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Update cpu load after task_tickAlex Shi1-1/+1
To get the latest runnable info, we need do this cpuload update after task_tick. Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-6-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Fix sleep time double accounting in enqueue entityAlex Shi1-1/+7
The woken migrated task will __synchronize_entity_decay(se); in migrate_task_rq_fair, then it needs to set `se->avg.last_runnable_update -= (-se->avg.decay_count) << 20' before update_entity_load_avg, in order to avoid sleep time is updated twice for se.avg.load_avg_contrib in both __syncchronize and update_entity_load_avg. However if the sleeping task is woken up from the same cpu, it miss the last_runnable_update before update_entity_load_avg(se, 0, 1), then the sleep time was used twice in both functions. So we need to remove the double sleep time accounting. Paul also contributed some code comments in this commit. Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-5-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Set an initial value of runnable avg for new forked taskAlex Shi3-4/+28
We need to initialize the se.avg.{decay_count, load_avg_contrib} for a new forked task. Otherwise random values of above variables cause a mess when a new task is enqueued: enqueue_task_fair enqueue_entity enqueue_entity_load_avg and make fork balancing imbalance due to incorrect load_avg_contrib. Further more, Morten Rasmussen notice some tasks were not launched at once after created. So Paul and Peter suggest giving a start value for new task runnable avg time same as sched_slice(). PeterZ said: > So the 'problem' is that our running avg is a 'floating' average; ie. it > decays with time. Now we have to guess about the future of our newly > spawned task -- something that is nigh impossible seeing these CPU > vendors keep refusing to implement the crystal ball instruction. > > So there's two asymptotic cases we want to deal well with; 1) the case > where the newly spawned program will be 'nearly' idle for its lifetime; > and 2) the case where its cpu-bound. > > Since we have to guess, we'll go for worst case and assume its > cpu-bound; now we don't want to make the avg so heavy adjusting to the > near-idle case takes forever. We want to be able to quickly adjust and > lower our running avg. > > Now we also don't want to make our avg too light, such that it gets > decremented just for the new task not having had a chance to run yet -- > even if when it would run, it would be more cpu-bound than not. > > So what we do is we make the initial avg of the same duration as that we > guess it takes to run each task on the system at least once -- aka > sched_slice(). > > Of course we can defeat this with wakeup/fork bombs, but in the 'normal' > case it should be good enough. Paul also contributed most of the code comments in this commit. Signed-off-by: Alex Shi <alex.shi@intel.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Reviewed-by: Paul Turner <pjt@google.com> [peterz; added explanation of sched_slice() usage] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-4-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27sched: Move a few runnable tg variables into CONFIG_SMPAlex Shi1-0/+2
The following 2 variables are only used under CONFIG_SMP, so its better to move their definiation into CONFIG_SMP too. atomic64_t load_avg; atomic_t runnable_avg; Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371694737-29336-3-git-send-email-alex.shi@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-27Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for ↵Alex Shi3-36/+7
load-tracking" Remove CONFIG_FAIR_GROUP_SCHED that covers the runnable info, then we can use runnable load variables. Also remove 2 CONFIG_FAIR_GROUP_SCHED setting which is not in reverted patch(introduced in 9ee474f), but also need to revert. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51CA76A3.3050207@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-26Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Three small fixlets" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot() hw_breakpoint: Fix cpu check in task_bp_pinned(cpu) kprobes: Fix arch_prepare_kprobe to handle copy insn failures
2013-06-26cgroup: always use RCU accessors for protected accessesTejun Heo1-9/+12
kernel/cgroup.c still has places where a RCU pointer is set and accessed directly without going through RCU_INIT_POINTER() or rcu_dereference_protected(). They're all properly protected accesses so nothing is broken but it leads to spurious sparse RCU address space warnings. Substitute direct accesses with RCU_INIT_POINTER() and rcu_dereference_protected(). Note that %true is specified as the extra condition for all derference updates. This isn't ideal as all it does is suppressing warning without actually policing synchronization rules; however, most are scheduled to be removed pretty soon along with css_id itself, so no reason to be more elaborate. Combined with the previous changes, this removes all RCU related sparse warnings from cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by; Li Zefan <lizefan@huawei.com>
2013-06-26cgroup: fix RCU accesses around task->cgroupsTejun Heo1-11/+13
There are several places in kernel/cgroup.c where task->cgroups is accessed and modified without going through proper RCU accessors. None is broken as they're all lock protected accesses; however, this still triggers sparse RCU address space warnings. * Consistently use task_css_set() for task->cgroups dereferencing. * Use RCU_INIT_POINTER() to clear task->cgroups to &init_css_set on exit. * Remove unnecessary rcu_dereference_raw() from cset->subsys[] dereference in cgroup_exit(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-26cgroup: grab cgroup_mutex in drop_parsed_module_refcounts()Tejun Heo1-5/+5
This isn't strictly necessary as all subsystems specified in @subsys_mask are guaranteed to be pinned; however, it does spuriously trigger lockdep warning. Let's grab cgroup_mutex around it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-26cgroup: fix cgroupfs_root early destruction pathTejun Heo1-3/+19
cgroupfs_root used to have ->actual_subsys_mask in addition to ->subsys_mask. a8a648c4ac ("cgroup: remove cgroup->actual_subsys_mask") removed it noting that the subsys_mask is essentially temporary and doesn't belong in cgroupfs_root; however, the patch made it impossible to tell whether a cgroupfs_root actually has the subsystems bound or just have the bits set leading to the following BUG when trying to mount with subsystems which are already mounted elsewhere. kernel BUG at kernel/cgroup.c:1038! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC ... CPU: 1 PID: 7973 Comm: mount Tainted: G W 3.10.0-rc7-next-20130625-sasha-00011-g1c1dc0e #1105 task: ffff880fc0ae8000 ti: ffff880fc0b9a000 task.ti: ffff880fc0b9a000 RIP: 0010:[<ffffffff81249b29>] [<ffffffff81249b29>] rebind_subsystems+0x409/0x5f0 ... Call Trace: [<ffffffff8124bd4f>] cgroup_kill_sb+0xff/0x210 [<ffffffff813d21af>] deactivate_locked_super+0x4f/0x90 [<ffffffff8124f3b3>] cgroup_mount+0x673/0x6e0 [<ffffffff81257169>] cpuset_mount+0xd9/0x110 [<ffffffff813d2580>] mount_fs+0xb0/0x2d0 [<ffffffff81404afd>] vfs_kern_mount+0xbd/0x180 [<ffffffff814070b5>] do_new_mount+0x145/0x2c0 [<ffffffff814085d6>] do_mount+0x356/0x3c0 [<ffffffff8140873d>] SyS_mount+0xfd/0x140 [<ffffffff854eb600>] tracesys+0xdd/0xe2 We still want rebind_subsystems() to take added/removed masks, so let's fix it by marking whether a cgroupfs_root has finished binding or not. Also, document what's going on around ->subsys_mask initialization so that similar mistakes aren't repeated. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-26mutex: Add w/w mutex slowpath debuggingDaniel Vetter1-3/+41
Injects EDEADLK conditions at pseudo-random interval, with exponential backoff up to UINT_MAX (to ensure that every lock operation still completes in a reasonable time). This way we can test the wound slowpath even for ww mutex users where contention is never expected, and the ww deadlock avoidance algorithm is only needed for correctness against malicious userspace. An example would be protecting kernel modesetting properties, which thanks to single-threaded X isn't really expected to contend, ever. I've looked into using the CONFIG_FAULT_INJECTION infrastructure, but decided against it for two reasons: - EDEADLK handling is mandatory for ww mutex users and should never affect the outcome of a syscall. This is in contrast to -ENOMEM injection. So fine configurability isn't required. - The fault injection framework only allows to set a simple probability for failure. Now the probability that a ww mutex acquire stage with N locks will never complete (due to too many injected EDEADLK backoffs) is zero. But the expected number of ww_mutex_lock operations for the completely uncontended case would be O(exp(N)). The per-acuiqire ctx exponential backoff solution choosen here only results in O(log N) overhead due to injection and so O(log N * N) lock operations. This way we can fail with high probability (and so have good test coverage even for fancy backoff and lock acquisition paths) without running into patalogical cases. Note that EDEADLK will only ever be injected when we managed to acquire the lock. This prevents any behaviour changes for users which rely on the EALREADY semantics. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130620113117.4001.21681.stgit@patser Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-26mutex: Add support for wound/wait style locksMaarten Lankhorst1-16/+302
Wound/wait mutexes are used when other multiple lock acquisitions of a similar type can be done in an arbitrary order. The deadlock handling used here is called wait/wound in the RDBMS literature: The older tasks waits until it can acquire the contended lock. The younger tasks needs to back off and drop all the locks it is currently holding, i.e. the younger task is wounded. For full documentation please read Documentation/ww-mutex-design.txt. References: https://lwn.net/Articles/548909/ Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Acked-by: Rob Clark <robdclark@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/51C8038C.9000106@canonical.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-26arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or notMaarten Lankhorst1-18/+14
This will allow me to call functions that have multiple arguments if fastpath fails. This is required to support ticket mutexes, because they need to be able to pass an extra argument to the fail function. Originally I duplicated the functions, by adding __mutex_fastpath_lock_retval_arg. This ended up being just a duplication of the existing function, so a way to test if fastpath was called ended up being better. This also cleaned up the reservation mutex patch some by being able to call an atomic_set instead of atomic_xchg, and making it easier to detect if the wrong unlock function was previously used. Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: dri-devel@lists.freedesktop.org Cc: linaro-mm-sig@lists.linaro.org Cc: robclark@gmail.com Cc: rostedt@goodmis.org Cc: daniel@ffwll.ch Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20130620113105.4001.83929.stgit@patser Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-26Merge tag 'please-pull-mce-bitmap-comment' of ↵Ingo Molnar10-106/+275
git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras Pull MCE updates from Tony Luck: "Better comments so we understand our existing machine check bank bitmaps - prelude to adding another bitmap soon." Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-25futex: Use freezable blocking callColin Cross1-1/+2
Avoid waking up every thread sleeping in a futex_wait call during suspend and resume by calling a freezable blocking call. Previous patches modified the freezer to avoid sending wakeups to threads that are blocked in freezable blocking calls. This call was selected to be converted to a freezable call because it doesn't hold any locks or release any resources when interrupted that might be needed by another freezing task or a kernel driver during suspend, and is a common site where idle userspace tasks are blocked. Signed-off-by: Colin Cross <ccross@android.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: arve@android.com Cc: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Darren Hart <dvhart@linux.intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/1367458508-9133-8-git-send-email-ccross@android.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-25futex: Take hugepages into account when generating futex_keyZhang Yi1-1/+2
The futex_keys of process shared futexes are generated from the page offset, the mapping host and the mapping index of the futex user space address. This should result in an unique identifier for each futex. Though this is not true when futexes are located in different subpages of an hugepage. The reason is, that the mapping index for all those futexes evaluates to the index of the base page of the hugetlbfs mapping. So a futex at offset 0 of the hugepage mapping and another one at offset PAGE_SIZE of the same hugepage mapping have identical futex_keys. This happens because the futex code blindly uses page->index. Steps to reproduce the bug: 1. Map a file from hugetlbfs. Initialize pthread_mutex1 at offset 0 and pthread_mutex2 at offset PAGE_SIZE of the hugetlbfs mapping. The mutexes must be initialized as PTHREAD_PROCESS_SHARED because PTHREAD_PROCESS_PRIVATE mutexes are not affected by this issue as their keys solely depend on the user space address. 2. Lock mutex1 and mutex2 3. Create thread1 and in the thread function lock mutex1, which results in thread1 blocking on the locked mutex1. 4. Create thread2 and in the thread function lock mutex2, which results in thread2 blocking on the locked mutex2. 5. Unlock mutex2. Despite the fact that mutex2 got unlocked, thread2 still blocks on mutex2 because the futex_key points to mutex1. To solve this issue we need to take the normal page index of the page which contains the futex into account, if the futex is in an hugetlbfs mapping. In other words, we calculate the normal page mapping index of the subpage in the hugetlbfs mapping. Mappings which are not based on hugetlbfs are not affected and still use page->index. Thanks to Mel Gorman who provided a patch for adding proper evaluation functions to the hugetlbfs code to avoid exposing hugetlbfs specific details to the futex code. [ tglx: Massaged changelog ] Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> Tested-by: Ma Chenggong <ma.chenggong@zte.com.cn> Reviewed-by: 'Mel Gorman' <mgorman@suse.de> Acked-by: 'Darren Hart' <dvhart@linux.intel.com> Cc: 'Peter Zijlstra' <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/000101ce71a6%24a83c5880%24f8b50980%24@com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-25cgroup: reserve ID 0 for dummy_root and 1 for unified hierarchyTejun Heo1-4/+6
Before 1a57423166 ("cgroup: make hierarchy_id use cyclic idr"), hierarchy IDs were allocated from 0. As the dummy hierarchy was always the one first initialized, it got assigned 0 and all other hierarchies from 1. The patch accidentally changed the minimum useable ID to 2. Let's restore ID 0 for dummy_root and while at it reserve 1 for unified hierarchy. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Cc: stable@vger.kernel.org
2013-06-25cgroup: implement for_each_[builtin_]subsys()Tejun Heo1-76/+71
There are quite a few places where all loaded [builtin] subsys are iterated. Implement for_each_[builtin_]subsys() and replace manual iterations with those to simplify those places a bit. The new iterators automatically skip NULL subsystems. This shouldn't cause any functional difference. Iteration loops which scan all subsystems and then skipping modular ones explicitly are converted to use for_each_builtin_subsys(). While at it, reorder variable declarations and adjust whitespaces a bit in the affected functions. v2: Add lockdep_assert_held() in for_each_subsys() and add comments about synchronization as suggested by Li. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-25cgroup: move init_css_set initialization inside cgroup_mutexTejun Heo1-4/+4
cgroup_init() was doing init_css_set initialization outside cgroup_mutex, which is fine but we want to add lockdep annotation on subsystem iterations and cgroup_init() will trigger it spuriously. Move init_css_set initialization inside cgroup_mutex. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-25irqdomain: Use irq_get_trigger_type() to get IRQ flagsJavier Martinez Canillas1-1/+1
Use irq_get_trigger_type() to get the IRQ trigger type flags instead calling irqd_get_trigger_type(irq_desc_get_irq_data(virq)) Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Acked-by: Grant Likely <grant.likely@linaro.org> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@linux-mips.org Link: http://lkml.kernel.org/r/1371228049-27080-8-git-send-email-javier.martinez@collabora.co.uk Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-24cgroup: s/for_each_subsys()/for_each_root_subsys()/Tejun Heo1-25/+22
for_each_subsys() walks over subsystems attached to a hierarchy and we're gonna add iterators which walk over all available subsystems. Rename for_each_subsys() to for_each_root_subsys() so that it's more appropriately named and for_each_subsys() can be used to iterate all subsystems. While at it, remove unnecessary underbar prefix from macro arguments, put them inside parentheses, and adjust indentation for the two for_each_*() macros. This patch is purely cosmetic. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-24cgroup: clean up find_css_set() and friendsTejun Heo1-21/+17
find_css_set() passes uninitialized on-stack template[] array to find_existing_css_set() which sets the entries for all subsystems. Passing around an uninitialized array is a bit icky and we want to introduce an iterator which only iterates loaded subsystems. Let's initialize it on definition. While at it, also make the following cosmetic cleanups. * Convert to proper /** comments. * Reorder variable declarations. * Replace comment on synchronization with lockdep_assert_held(). This patch doesn't make any functional differences. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-24cgroup: remove cgroup->actual_subsys_maskTejun Heo1-10/+12
cgroup curiously has two subsystem masks, ->subsys_mask and ->actual_subsys_mask. The latter only exists because the new target subsys_mask is passed into rebind_subsystems() via @root>subsys_mask. rebind_subsystems() needs to know what the current mask is to decide how to reach the target mask so ->actual_subsys_mask is used as the temp location to remember the current state. Adding a temporary field to a permanent data structure is rather silly and can be misleading. Update rebind_subsystems() to take @added_mask and @removed_mask instead and remove @root->actual_subsys_mask. This patch shouldn't introduce any behavior changes. v2: Comment and description updated as suggested by Li. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-24cgroup: prefix global variables with "cgroup_"Tejun Heo1-76/+77
Global variable names in kernel/cgroup.c are asking for trouble - subsys, roots, rootnode and so on. Rename them to have "cgroup_" prefix. * s/subsys/cgroup_subsys/ * s/rootnode/cgroup_dummy_root/ * s/dummytop/cgroup_cummy_top/ * s/roots/cgroup_roots/ * s/root_count/cgroup_root_count/ This patch is purely cosmetic. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2013-06-24Merge 3.10-rc7 into driver-core-nextGreg Kroah-Hartman10-106/+275
We want the firmware merge fixes, and other bits, in here now. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-24genirq: Irqchip: document gcflags arg of irq_alloc_domain_generic_chipsJames Hogan1-0/+1
Commit 088f40b7b027dad6519712ff224a5798dd62a204 ("genirq: Generic chip: Add linear irq domain support") missed kerneldoc for the gcflags argument of irq_alloc_domain_generic_chips(). Add it now. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Link: http://lkml.kernel.org/r/1371564513-4327-1-git-send-email-james.hogan@imgtec.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-24PM / QoS: Add pm_qos_request tracepointsSahara1-0/+5
Adds tracepoints to pm_qos_add_request, pm_qos_update_request, pm_qos_remove_request, and pm_qos_update_request_timeout. It's useful for checking pm_qos_class, value, and timeout_us. Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-24PM / QoS: Add pm_qos_update_target/flags tracepointsSahara1-0/+3
This patch adds tracepoints to pm_qos_update_target and pm_qos_update_flags. It's useful for checking pm qos action, previous value and current value. Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-23perf: Drop sample rate when sampling is too slowDave Hansen2-4/+97
This patch keeps track of how long perf's NMI handler is taking, and also calculates how many samples perf can take a second. If the sample length times the expected max number of samples exceeds a configurable threshold, it drops the sample rate. This way, we don't have a runaway sampling process eating up the CPU. This patch can tend to drop the sample rate down to level where perf doesn't work very well. *BUT* the alternative is that my system hangs because it spends all of its time handling NMIs. I'll take a busted performance tool over an entire system that's busted and undebuggable any day. BTW, my suspicion is that there's still an underlying bug here. Using the HPET instead of the TSC is definitely a contributing factor, but I suspect there are some other things going on. But, I can't go dig down on a bug like that with my machine hanging all the time. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> [ Prettified it a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-21Merge branch 'x86/urgent' of ↵Linus Torvalds1-10/+11
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "This series fixes a couple of build failures, and fixes MTRR cleanup and memory setup on very specific memory maps. Finally, it fixes triggering backtraces on all CPUs, which was inadvertently disabled on x86." * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/efi: Fix dummy variable buffer allocation x86: Fix trigger_all_cpu_backtrace() implementation x86: Fix section mismatch on load_ucode_ap x86: fix build error and kconfig for ia32_emulation and binfmt range: Do not add new blank slot with add_range_with_merge x86, mtrr: Fix original mtrr range get for mtrr_cleanup
2013-06-21tick: Fix tick_broadcast_pending_mask not clearedDaniel Lezcano1-2/+5
The recent modification in the cpuidle framework consolidated the timer broadcast code across the different drivers by setting a new flag in the idle state. It tells the cpuidle core code to enter/exit the broadcast mode for the cpu when entering a deep idle state. The broadcast timer enter/exit is no longer handled by the back-end driver. This change made the local interrupt to be enabled *before* calling CLOCK_EVENT_NOTIFY_EXIT. On a tegra114, a four cores system, when the flag has been introduced in the driver, the following warning appeared: WARNING: at kernel/time/tick-broadcast.c:578 tick_broadcast_oneshot_control CPU: 2 PID: 0 Comm: swapper/2 Not tainted 3.10.0-rc3-next-20130529+ #15 [<c00667f8>] (tick_broadcast_oneshot_control+0x1a4/0x1d0) from [<c0065cd0>] (tick_notify+0x240/0x40c) [<c0065cd0>] (tick_notify+0x240/0x40c) from [<c0044724>] (notifier_call_chain+0x44/0x84) [<c0044724>] (notifier_call_chain+0x44/0x84) from [<c0044828>] (raw_notifier_call_chain+0x18/0x20) [<c0044828>] (raw_notifier_call_chain+0x18/0x20) from [<c00650cc>] (clockevents_notify+0x28/0x170) [<c00650cc>] (clockevents_notify+0x28/0x170) from [<c033f1f0>] (cpuidle_idle_call+0x11c/0x168) [<c033f1f0>] (cpuidle_idle_call+0x11c/0x168) from [<c000ea94>] (arch_cpu_idle+0x8/0x38) [<c000ea94>] (arch_cpu_idle+0x8/0x38) from [<c005ea80>] (cpu_startup_entry+0x60/0x134) [<c005ea80>] (cpu_startup_entry+0x60/0x134) from [<804fe9a4>] (0x804fe9a4) I don't have the hardware, so I wasn't able to reproduce the warning but after looking a while at the code, I deduced the following: 1. the CPU2 enters a deep idle state and sets the broadcast timer 2. the timer expires, the tick_handle_oneshot_broadcast function is called, setting the tick_broadcast_pending_mask and waking up the idle cpu CPU2 3. the CPU2 exits idle handles the interrupt and then invokes tick_broadcast_oneshot_control with CLOCK_EVENT_NOTIFY_EXIT which runs the following code: [...] if (dev->next_event.tv64 == KTIME_MAX) goto out; if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_pending_mask)) goto out; [...] So if there is no next event scheduled for CPU2, we fulfil the first condition and jump out without clearing the tick_broadcast_pending_mask. 4. CPU2 goes to deep idle again and calls tick_broadcast_oneshot_control with CLOCK_NOTIFY_EVENT_ENTER but with the tick_broadcast_pending_mask set for CPU2, triggering the warning. The issue only surfaced due to the modifications of the cpuidle framework, which resulted in interrupts being enabled before the call to the clockevents code. If the call happens before interrupts have been enabled, the warning cannot trigger, because there is still the event pending which caused the broadcast timer expiry. Move the check for the next event below the check for the pending bit, so the pending bit gets cleared whether an event is scheduled on the cpu or not. [ tglx: Massaged changelog ] Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reported-and-tested-by: Joseph Lo <josephl@nvidia.com> Cc: Stephen Warren <swarren@nvidia.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/r/1371485735-31249-1-git-send-email-daniel.lezcano@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-21PM / Sleep: Print last wakeup source on failed wakeup_count writeJulius Werner1-0/+2
Commit a938da06 introduced a useful little log message to tell users/debuggers which wakeup source aborted a suspend. However, this message is only printed if the abort happens during the in-kernel suspend path (after writing /sys/power/state). The full specification of the /sys/power/wakeup_count facility allows user-space power managers to double-check if wakeups have already happened before it actually tries to suspend (e.g. while it was running user-space pre-suspend hooks), by writing the last known wakeup_count value to /sys/power/wakeup_count. This patch changes the sysfs handler for that node to also print said log message if that write fails, so that we can figure out the offending wakeup source for both kinds of suspend aborts. Signed-off-by: Julius Werner <jwerner@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-21PM / QoS: correct the valid range of pm_qos_classSahara1-3/+3
The valid start index for pm_qos_array is not 0, but PM_QOS_CPU_DMA_LATENCY. There is a null_pm_qos at index 0 of pm_qos_array. However, null_pm_qos is not created as misc device so that inclusion of 0 index for checking pm_qos_class especially for file operations is not proper here. [rjw: Changelog, a bit] Signed-off-by: Sahara <keun-o.park@windriver.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-20Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2-4/+57
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Two smaller fixes - plus a context tracking tracing fix that is a bit bigger" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tracing/context-tracking: Add preempt_schedule_context() for tracing sched: Fix clear NOHZ_BALANCE_KICK sched/x86: Construct all sibling maps if smt
2013-06-20Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds3-82/+185
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Four fixes. The mmap ones are unfortunately larger than desired - fuzzing uncovered bugs that needed perf context life time management changes to fix properly" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86: Fix broken PEBS-LL support on SNB-EP/IVB-EP perf: Fix mmap() accounting hole perf: Fix perf mmap bugs kprobes: Fix to free gone and unused optprobes
2013-06-20Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds1-0/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull cpu idle fixes from Thomas Gleixner: - Add a missing irq enable. Fallout of the idle conversion - Fix stackprotector wreckage caused by the idle conversion * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: idle: Enable interrupts in the weak arch_cpu_idle() implementation idle: Add the stack canary init to cpu_startup_entry()
2013-06-20Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds5-10/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: - Fix inconstinant clock usage in virtual time accounting - Fix a build error in KVM caused by the NOHZ work - Remove a pointless timekeeping duty assignment which breaks NOHZ - Use a proper notifier return value to avoid random behaviour * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick: Remove useless timekeeping duty attribution to broadcast source nohz: Fix notifier return val that enforce timekeeping kvm: Move guest entry/exit APIs to context_tracking vtime: Use consistent clocks among nohz accounting
2013-06-20hw_breakpoint: Introduce "struct bp_cpuinfo"Oleg Nesterov1-33/+36
This patch simply moves all per-cpu variables into the new single per-cpu "struct bp_cpuinfo". To me this looks more logical and clean, but this can also simplify the further potential changes. In particular, I do not think this memory should be per-cpu, it is never used "locally". After this change it is trivial to turn it into, say, bootmem[nr_cpu_ids]. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155020.GA6350@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify *register_wide_hw_breakpoint()Oleg Nesterov1-23/+11
1. register_wide_hw_breakpoint() can use unregister_ if failure, no need to duplicate the code. 2. "struct perf_event **pevent" adds the unnecesary lever of indirection and complication, use per_cpu(*cpu_events, cpu). Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155018.GA6347@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Introduce cpumask_of_bp()Oleg Nesterov1-26/+17
Add the trivial helper which simply returns cpumask_of() or cpu_possible_mask depending on bp->cpu. Change fetch_bp_busy_slots() and toggle_bp_slot() to always do for_each_cpu(cpumask_of_bp) to simplify the code and avoid the code duplication. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155015.GA6340@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() pathsOleg Nesterov1-12/+8
Change toggle_bp_slot() to make "weight" negative if !enable. This way we can always use "+ weight" without additional "if (enable)" check and toggle_bp_task_slot() no longer needs this arg. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155013.GA6337@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() pathsOleg Nesterov1-24/+16
The enable/disable logic in toggle_bp_slot() is not symmetrical and imho very confusing. "old_count" in toggle_bp_task_slot() is actually new_count because this bp was already removed from the list. Change toggle_bp_slot() to always call list_add/list_del after toggle_bp_task_slot(). This way old_idx is task_bp_pinned() and this entry should be decremented, new_idx is +/-weight and we need to increment this element. The code/logic looks obvious. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20130620155011.GA6330@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20Merge branch 'perf/urgent' into perf/coreIngo Molnar1-3/+3
Merge in two hw_breakpoint fixes, before applying another 5. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot()Oleg Nesterov1-2/+2
fetch_bp_busy_slots() and toggle_bp_slot() use for_each_online_cpu(), this is obviously wrong wrt cpu_up() or cpu_down(), we can over/under account the per-cpu numbers. For example: # echo 0 >> /sys/devices/system/cpu/cpu1/online # perf record -e mem:0x10 -p 1 & # echo 1 >> /sys/devices/system/cpu/cpu1/online # perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10 -C1 -a & # taskset -p 0x2 1 triggers the same WARN_ONCE("Can't find any breakpoint slot") in arch_install_hw_breakpoint(). Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20130620155009.GA6327@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-20hw_breakpoint: Fix cpu check in task_bp_pinned(cpu)Oleg Nesterov1-1/+1
trinity fuzzer triggered WARN_ONCE("Can't find any breakpoint slot") in arch_install_hw_breakpoint() but the problem is not arch-specific. The problem is, task_bp_pinned(cpu) checks "cpu == iter->cpu" but this doesn't account the "all cpus" events with iter->cpu < 0. This means that, say, register_user_hw_breakpoint(tsk) can happily create the arbitrary number > HBP_NUM of breakpoints which can not be activated. toggle_bp_task_slot() is equally wrong by the same reason and nr_task_bp_pinned[] can have negative entries. Simple test: # perl -e 'sleep 1 while 1' & # perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10,mem:0x10 -p `pidof perl` Before this patch this triggers the same problem/WARN_ON(), after the patch it correctly fails with -ENOSPC. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20130620155006.GA6324@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19Merge tag 'please-pull-einj' of ↵Ingo Molnar1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/ras Pull miscellaneous fixes for ACPI EINJ (error injection) code, from Tony Luck. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19Merge branch 'rcu/next' of ↵Ingo Molnar7-1208/+154
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: "The major changes for this series are: 1. Simplify RCU's grace-period and callback processing based on the new numbering for callbacks. These were posted to LKML at https://lkml.org/lkml/2013/5/20/330. 2. Documentation updates. These were posted to LKML at https://lkml.org/lkml/2013/5/20/348. 3. Miscellaneous fixes, including converting a few remaining printk() calls to pr_*(). These were posted to LKML at https://lkml.org/lkml/2013/5/20/324. 4. SRCU-related changes and fixes. These were posted to LKML at https://lkml.org/lkml/2013/5/20/425. 5. Removal of TINY_PREEMPT_RCU in favor of TREE_PREEMPT_RCU for single-CPU low-latency systems. These were posted to LKML at https://lkml.org/lkml/2013/5/20/427." Signed-off-by: Ingo Molnar <mingo@kernel.org>
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