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2013-06-26arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or notMaarten Lankhorst
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 Molnar
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 Cross
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 Yi
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 Heo
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 Heo
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 Heo
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 Canillas
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 Heo
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 Heo
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 Heo
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 Heo
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-Hartman
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 Hogan
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>
2013-06-23perf: Drop sample rate when sampling is too slowDave Hansen
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 Torvalds
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 Lezcano
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>
2013-06-20Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
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 Torvalds
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 Torvalds
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 Torvalds
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Molnar
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 Nesterov
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 Nesterov
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 Molnar
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 Molnar
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>
2013-06-19sched: Don't mix use of typedef ctl_table and struct ctl_tableJoe Perches
Just use struct ctl_table. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1371063336.2069.22.camel@joe-AO722 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Remove WARN_ON(!sd) from init_sched_groups_power()Viresh Kumar
sd can't be NULL in init_sched_groups_power() and so checking it for NULL isn't useful. In case it is required, then also we need to rearrange the code a bit as we already accessed invalid pointer sd to get sg: sg = sd->groups. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2bbe633cd74b431c05253a8ce61fdfd5066a531b.1370948150.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Fix memory leakage in build_sched_groups()Viresh Kumar
In build_sched_groups() we don't need to call get_group() for cpus which are already covered in previous iterations. Calling get_group() would mark the group used and eventually leak it since we wouldn't connect it and not find it again to free it. This will happen only in cases where sg->cpumask contained more than one cpu (For any topology level). This patch would free sg's memory for all cpus leaving the group leader as the group isn't marked used now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/7a61e955abdcbb1dfa9fe493f11a5ec53a11ddd3.1370948150.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Use cached value of span instead of calling sched_domain_span()Viresh Kumar
In the beginning of build_sched_groups() we called sched_domain_span() and cached its return value in span. Few statements later we are calling it again to get the same pointer. Lets use the cached value instead as it hasn't changed in between. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/834ecd507071ad88aff039352dbc7e063dd996a7.1370948150.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Create for_each_sd_topology()Viresh Kumar
For loop for traversing sched_domain_topology was used at multiple placed in core.c. This patch removes code redundancy by creating for_each_sd_topology(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/e0e04542f54e9464bd9da54f5ccfe62ec6c4c0bc.1370861520.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Don't set sd->child to NULL when it is already NULLViresh Kumar
Memory for sd is allocated with kzalloc_node() which will initialize its fields with zero. In build_sched_domain() we are setting sd->child to child even if child is NULL, which isn't required. Lets do it only if child isn't NULL. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/f4753a1730051341003ad2ad29a3229c7356678e.1370861520.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Don't initialize alloc_state in build_sched_domains()Viresh Kumar
alloc_state will be overwritten by __visit_domain_allocation_hell() and so we don't actually need to initialize alloc_state. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/df57734a075cc5ad130e1ae498702e24f2529ab8.1370861520.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Optimize build_sched_domains() for saving first SD node for a cpuViresh Kumar
We are saving first scheduling domain for a cpu in build_sched_domains() by iterating over the nested sd->child list. We don't actually need to do it this way. tl will be equal to sched_domain_topology for the first iteration and so we can set *per_cpu_ptr(d.sd, i) based on that. So, save pointer to first SD while running the iteration loop over tl's. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/fc473527cbc4dfa0b8eeef2a59db74684eb59a83.1370436120.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Remove unused params of build_sched_domain()Viresh Kumar
build_sched_domain() never uses parameter struct s_data *d and so passing it is useless. Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/545e0b4536166a15b4475abcafe5ed0db4ad4a2c.1370436120.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Rename sched.c as sched/core.c in comments and DocumentationViresh Kumar
Most of the stuff from kernel/sched.c was moved to kernel/sched/core.c long time back and the comments/Documentation never got updated. I figured it out when I was going through sched-domains.txt and so thought of fixing it globally. I haven't crossed check if the stuff that is referenced in sched/core.c by all these files is still present and hasn't changed as that wasn't the motive behind this patch. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/cdff76a265326ab8d71922a1db5be599f20aad45.1370329560.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Femove the useless declaration in kernel/sched/fair.cMichael Wang
default_cfs_period(), do_sched_cfs_period_timer(), do_sched_cfs_slack_timer() already defined previously, no need to declare again. Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51AD8808.7020608@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Refine the code in unthrottle_cfs_rq()Michael Wang
Directly use rq to save some code. Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/51AD87EB.1070605@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched/rt: Simplify pull_rt_task() logic and remove .leaf_rt_rq_listKirill Tkhai
[ Peter, this is based off of some of my work, I ran it though a few tests and it passed. I also reviewed it, and added my SOB as I am somewhat a co-author to it. ] Based on the patch by Steven Rostedt from previous year: https://lkml.org/lkml/2012/4/18/517 1)Simplify pull_rt_task() logic: search in pushable tasks of dest runqueue. The only pullable tasks are the tasks which are pushable in their local rq, and no others. 2)Remove .leaf_rt_rq_list member of struct rt_rq and functions connected with it: nobody uses it since now. Signed-off-by: Kirill Tkhai <tkhai@yandex.ru> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/287571370557898@web7d.yandex.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19Merge branch 'sched/urgent' into sched/coreIngo Molnar
Merge in fixes before applying ongoing new work. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19tracing/context-tracking: Add preempt_schedule_context() for tracingSteven Rostedt
Dave Jones hit the following bug report: =============================== [ INFO: suspicious RCU usage. ] 3.10.0-rc2+ #1 Not tainted ------------------------------- include/linux/rcupdate.h:771 rcu_read_lock() used illegally while idle! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 2 locks held by cc1/63645: #0: (&rq->lock){-.-.-.}, at: [<ffffffff816b39fd>] __schedule+0xed/0x9b0 #1: (rcu_read_lock){.+.+..}, at: [<ffffffff8109d645>] cpuacct_charge+0x5/0x1f0 CPU: 1 PID: 63645 Comm: cc1 Not tainted 3.10.0-rc2+ #1 [loadavg: 40.57 27.55 13.39 25/277 64369] Hardware name: Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H, BIOS F12a 04/23/2010 0000000000000000 ffff88010f78fcf8 ffffffff816ae383 ffff88010f78fd28 ffffffff810b698d ffff88011c092548 000000000023d073 ffff88011c092500 0000000000000001 ffff88010f78fd60 ffffffff8109d7c5 ffffffff8109d645 Call Trace: [<ffffffff816ae383>] dump_stack+0x19/0x1b [<ffffffff810b698d>] lockdep_rcu_suspicious+0xfd/0x130 [<ffffffff8109d7c5>] cpuacct_charge+0x185/0x1f0 [<ffffffff8109d645>] ? cpuacct_charge+0x5/0x1f0 [<ffffffff8108dffc>] update_curr+0xec/0x240 [<ffffffff8108f528>] put_prev_task_fair+0x228/0x480 [<ffffffff816b3a71>] __schedule+0x161/0x9b0 [<ffffffff816b4721>] preempt_schedule+0x51/0x80 [<ffffffff816b4800>] ? __cond_resched_softirq+0x60/0x60 [<ffffffff816b6824>] ? retint_careful+0x12/0x2e [<ffffffff810ff3cc>] ftrace_ops_control_func+0x1dc/0x210 [<ffffffff816be280>] ftrace_call+0x5/0x2f [<ffffffff816b681d>] ? retint_careful+0xb/0x2e [<ffffffff816b4805>] ? schedule_user+0x5/0x70 [<ffffffff816b4805>] ? schedule_user+0x5/0x70 [<ffffffff816b6824>] ? retint_careful+0x12/0x2e ------------[ cut here ]------------ What happened was that the function tracer traced the schedule_user() code that tells RCU that the system is coming back from userspace, and to add the CPU back to the RCU monitoring. Because the function tracer does a preempt_disable/enable_notrace() calls the preempt_enable_notrace() checks the NEED_RESCHED flag. If it is set, then preempt_schedule() is called. But this is called before the user_exit() function can inform the kernel that the CPU is no longer in user mode and needs to be accounted for by RCU. The fix is to create a new preempt_schedule_context() that checks if the kernel is still in user mode and if so to switch it to kernel mode before calling schedule. It also switches back to user mode coming back from schedule in need be. The only user of this currently is the preempt_enable_notrace(), which is only used by the tracing subsystem. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1369423420.6828.226.camel@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19sched: Fix clear NOHZ_BALANCE_KICKVincent Guittot
I have faced a sequence where the Idle Load Balance was sometime not triggered for a while on my platform, in the following scenario: CPU 0 and CPU 1 are running tasks and CPU 2 is idle CPU 1 kicks the Idle Load Balance CPU 1 selects CPU 2 as the new Idle Load Balancer CPU 2 sets NOHZ_BALANCE_KICK for CPU 2 CPU 2 sends a reschedule IPI to CPU 2 While CPU 3 wakes up, CPU 0 or CPU 1 migrates a waking up task A on CPU 2 CPU 2 finally wakes up, runs task A and discards the Idle Load Balance task A quickly goes back to sleep (before a tick occurs on CPU 2) CPU 2 goes back to idle with NOHZ_BALANCE_KICK set Whenever CPU 2 will be selected as the ILB, no reschedule IPI will be sent because NOHZ_BALANCE_KICK is already set and no Idle Load Balance will be performed. We must wait for the sched softirq to be raised on CPU 2 thanks to another part the kernel to come back to clear NOHZ_BALANCE_KICK. The proposed solution clears NOHZ_BALANCE_KICK in schedule_ipi if we can't raise the sched_softirq for the Idle Load Balance. Change since V1: - move the clear of NOHZ_BALANCE_KICK in got_nohz_idle_kick if the ILB can't run on this CPU (as suggested by Peter) Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1370419991-13870-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19perf: Add const qualifier to perf_pmu_register's 'name' argMischa Jonker
This allows us to use pdev->name for registering a PMU device. IMO the name is not supposed to be changed anyway. Signed-off-by: Mischa Jonker <mjonker@synopsys.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1370339148-5566-1-git-send-email-mjonker@synopsys.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19perf: Fix hypervisor branch sampling permission checkStephane Eranian
Commit 2b923c8 perf/x86: Check branch sampling priv level in generic code was missing the check for the hypervisor (HV) priv level, so add it back. With this patch, we get the following correct behavior: # echo 2 >/proc/sys/kernel/perf_event_paranoid $ perf record -j any,k noploop 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid: -1 - Not paranoid at all 0 - Disallow raw tracepoint access for unpriv 1 - Disallow cpu events for unpriv 2 - Disallow kernel profiling for unpriv $ perf record -j any,hv noploop 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid: -1 - Not paranoid at all 0 - Disallow raw tracepoint access for unpriv 1 - Disallow cpu events for unpriv 2 - Disallow kernel profiling for unpriv Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Petr Matousek <pmatouse@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20130606090204.GA3725@quad Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-19Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge in the latest fixes, to avoid conflicts with ongoing work. Signed-off-by: Ingo Molnar <mingo@kernel.org>