aboutsummaryrefslogtreecommitdiff
path: root/kernel
AgeCommit message (Collapse)AuthorFilesLines
2011-06-15Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Check if lowest_mask is initialized in find_lowest_rq() sched: Fix need_resched() when checking peempt
2011-06-15gcov: disable CONFIG_CONSTRUCTORS when not needed by CONFIG_GCOV_KERNELJosh Triplett1-1/+2
CONFIG_CONSTRUCTORS controls support for running constructor functions at kernel init time. According to commit b99b87f70c7785ab ("kernel: constructor support"), gcov (CONFIG_GCOV_KERNEL) needs this. However, CONFIG_CONSTRUCTORS currently defaults to y, with no option to disable it, and CONFIG_GCOV_KERNEL depends on it. Instead, default it to n and have CONFIG_GCOV_KERNEL select it, so that the normal case of CONFIG_GCOV_KERNEL=n will result in CONFIG_CONSTRUCTORS=n. Observed in the short list of =y values in a minimal kernel configuration. Signed-off-by: Josh Triplett <[email protected]> Acked-by: WANG Cong <[email protected]> Acked-by: Peter Oberparleiter <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-06-15memcg: clear mm->owner when last possible owner leavesKAMEZAWA Hiroyuki1-16/+15
The following crash was reported: > Call Trace: > [<ffffffff81139792>] mem_cgroup_from_task+0x15/0x17 > [<ffffffff8113a75a>] __mem_cgroup_try_charge+0x148/0x4b4 > [<ffffffff810493f3>] ? need_resched+0x23/0x2d > [<ffffffff814cbf43>] ? preempt_schedule+0x46/0x4f > [<ffffffff8113afe8>] mem_cgroup_charge_common+0x9a/0xce > [<ffffffff8113b6d1>] mem_cgroup_newpage_charge+0x5d/0x5f > [<ffffffff81134024>] khugepaged+0x5da/0xfaf > [<ffffffff81078ea0>] ? __init_waitqueue_head+0x4b/0x4b > [<ffffffff81133a4a>] ? add_mm_counter.constprop.5+0x13/0x13 > [<ffffffff81078625>] kthread+0xa8/0xb0 > [<ffffffff814d13e8>] ? sub_preempt_count+0xa1/0xb4 > [<ffffffff814d5664>] kernel_thread_helper+0x4/0x10 > [<ffffffff814ce858>] ? retint_restore_args+0x13/0x13 > [<ffffffff8107857d>] ? __init_kthread_worker+0x5a/0x5a What happens is that khugepaged tries to charge a huge page against an mm whose last possible owner has already exited, and the memory controller crashes when the stale mm->owner is used to look up the cgroup to charge. mm->owner has never been set to NULL with the last owner going away, but nobody cared until khugepaged came along. Even then it wasn't a problem because the final mmput() on an mm was forced to acquire and release mmap_sem in write-mode, preventing an exiting owner to go away while the mmap_sem was held, and until "692e0b3 mm: thp: optimize memcg charge in khugepaged", the memory cgroup charge was protected by mmap_sem in read-mode. Instead of going back to relying on the mmap_sem to enforce lifetime of a task, this patch ensures that mm->owner is properly set to NULL when the last possible owner is exiting, which the memory controller can handle just fine. [[email protected]: tweak comments] Signed-off-by: Hugh Dickins <[email protected]> Signed-off-by: KAMEZAWA Hiroyuki <[email protected]> Signed-off-by: Johannes Weiner <[email protected]> Reported-by: Hugh Dickins <[email protected]> Reported-by: Dave Jones <[email protected]> Reviewed-by: Andrea Arcangeli <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-06-15sched: Check if lowest_mask is initialized in find_lowest_rq()Steven Rostedt1-0/+4
On system boot up, the lowest_mask is initialized with an early_initcall(). But RT tasks may wake up on other early_initcall() callers before the lowest_mask is initialized, causing a system crash. Commit "d72bce0e67 rcu: Cure load woes" was the first commit to wake up RT tasks in early init. Before this commit this bug should not happen. Reported-by: Andrew Theurer <[email protected]> Tested-by: Andrew Theurer <[email protected]> Tested-by: Paul E. McKenney <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-06-15sched: Fix need_resched() when checking peemptHillf Danton1-1/+1
The RT preempt check tests the wrong task if NEED_RESCHED is set. It currently checks the local CPU task. It is supposed to check the task that is running on the runqueue we are about to wake another task on. Signed-off-by: Hillf Danton <[email protected]> Reviewed-by: Yong Zhang <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-06-14signal.c: fix kernel-doc notationRandy Dunlap1-1/+1
Fix kernel-doc warnings in signal.c: Warning(kernel/signal.c:2374): No description found for parameter 'nset' Warning(kernel/signal.c:2374): Excess function parameter 'set' description in 'sys_rt_sigprocmask' Signed-off-by: Randy Dunlap <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-06-13Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2-3/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs kprobes/trace: Fix kprobe selftest for gcc 4.6 ftrace: Fix possible undefined return code oprofile, dcookies: Fix possible circular locking dependency oprofile: Fix locking dependency in sync_start() oprofile: Free potentially owned tasks in case of errors oprofile, x86: Add comments to IBS LVT offset initialization
2011-06-10genirq: Prevent potential NULL dereference in irq_set_irq_wake()Jesper Juhl1-0/+3
In kernel/irq/manage.c::irq_set_irq_wake() we call irq_get_desc_buslock() which may return NULL, but the code dereferences the result unconditionally. irq_set_irq_wake() has lots of callers - I checked a few and I couldn't find anything that guarantees that they won't call it with some input that will cause irq_get_desc_buslock() to return NULL, so I think it's a good thing to test and -EINVAL was the most sane error code in this situation that I could think of. Not all callers test the return value of irq_set_irq_wake(), but those that do take != 0 to mean error as far as I can see, so they should be fine. I guess those that don't test actually should, but that's a different issue. Signed-off-by: Jesper Juhl <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-08Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2-18/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix comments in include/linux/perf_event.h perf: Comment /proc/sys/kernel/perf_event_paranoid to be part of user ABI perf python: Fix argument name list of read_on_cpu() perf evlist: Don't die if sample_{id_all|type} is invalid perf python: Use exception to propagate errors perf evlist: Remove dependency on debug routines perf, cgroups: Fix up for new API
2011-06-07Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds4-25/+50
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Ensure we locate the passed IRQ in irq_alloc_descs() genirq: Fix descriptor init on non-sparse IRQs irq: Handle spurios irq detection for threaded irqs genirq: Print threaded handler in spurious debug output
2011-06-07Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2-10/+25
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix/clarify set_task_cpu() locking rules lockdep: Fix lock_is_held() on recursion sched: Fix schedstat.nr_wakeups_migrate sched: Fix cross-cpu clock sync on remote wakeups
2011-06-07ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqsSteven Rostedt1-0/+7
Revert the commit that removed the disabling of interrupts around the initial modifying of mcount callers to nops, and update the comment. The original comment was outdated and stated that the interrupts were being disabled to prevent kstop machine, which was required with the old ftrace daemon, but was no longer the case. What the comment failed to mention was that interrupts needed to be disabled to keep interrupts from preempting the modifying of the code and then executing the code that was partially modified. Revert the commit and update the comment. Reported-by: Richard W.M. Jones <[email protected]> Tested-by: Richard W.M. Jones <[email protected]> Signed-off-by: Steven Rostedt <[email protected]>
2011-06-07kprobes/trace: Fix kprobe selftest for gcc 4.6Steven Rostedt1-2/+6
With gcc 4.6, the self test kprobe function: kprobe_trace_selftest_target() is optimized such that kallsyms does not list it. The kprobes test uses this function to insert a probe and test it. But it will fail the test if the function is not listed in kallsyms. Adding a __used annotation keeps the symbol in the kallsyms table. Suggested-by: David Daney <[email protected]> Cc: Masami Hiramatsu <[email protected]> Signed-off-by: Steven Rostedt <[email protected]>
2011-06-07sched: Fix/clarify set_task_cpu() locking rulesPeter Zijlstra1-5/+16
Sergey reported a CONFIG_PROVE_RCU warning in push_rt_task where set_task_cpu() was called with both relevant rq->locks held, which should be sufficient for running tasks since holding its rq->lock will serialize against sched_move_task(). Update the comments and fix the task_group() lockdep test. Reported-and-tested-by: Sergey Senozhatsky <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/1307115427.2353.3456.camel@twins Signed-off-by: Ingo Molnar <[email protected]>
2011-06-07lockdep: Fix lock_is_held() on recursionPeter Zijlstra1-1/+1
The main lock_is_held() user is lockdep_assert_held(), avoid false assertions in lockdep_off() sections by unconditionally reporting the lock is taken. [ the reason this is important is a lockdep_assert_held() in ttwu() which triggers a warning under lockdep_off() as in printk() which can trigger another wakeup and lock up due to spinlock recursion, as reported and heroically debugged by Arne Jansen ] Reported-and-tested-by: Arne Jansen <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/r/1307398759.2497.966.camel@laptop Signed-off-by: Ingo Molnar <[email protected]>
2011-06-06ftrace: Fix possible undefined return codeGuoWen Li1-1/+1
kernel/trace/ftrace.c: In function 'ftrace_regex_write.clone.15': kernel/trace/ftrace.c:2743:6: warning: 'ret' may be used uninitialized in this function Signed-off-by: GuoWen Li <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Steven Rostedt <[email protected]>
2011-06-04perf: Comment /proc/sys/kernel/perf_event_paranoid to be part of user ABIVince Weaver1-0/+6
Turns out that distro packages use this file as an indicator of the perf event subsystem - this is easier to check for from scripts than the existence of the system call. This is easy enough to keep around for the kernel, so add a comment to make sure it stays so. Signed-off-by: Vince Weaver <[email protected]> Cc: David Ahern <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Linus Torvalds <[email protected]> Cc: Andrew Morton <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-06-04Merge branch 'perf/urgent' of ↵Ingo Molnar20-233/+337
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent
2011-06-03timers: Consider slack value in mod_timer()Sebastian Andrzej Siewior1-8/+7
There is an optimization which does not update the timer if the timer was pending and the expiration time was unchanged. Since commit 3bbb9ec9 ("timers: Introduce the concept of timer slack for legacy timers") this optimization is no longer applied for timers where the expiration time got extended due to the slack value. So we need to check again after the expiration time might have been updated. [ tglx: Made it a single check by applying slack first and sorting out the slack = 0 value (all timeouts < 256 jiffies) early ] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-03genirq: Ensure we locate the passed IRQ in irq_alloc_descs()Mark Brown1-0/+6
When irq_alloc_descs() is called with no base IRQ specified then it will search for a range of IRQs starting from a specified base address. In the case where an IRQ is specified it still does this search in order to ensure that none of the requested range is already allocated and it still uses the from parameter to specify the base for the search. This means that in the case where a base is specified but from is zero (which is reasonable as any IRQ number is in the range specified by a zero from) the function will get confused and try to allocate the first suitably sized block of free IRQs it finds. Instead use a specified IRQ as the base address for the search, and insist that any from that is specified can support that IRQ. Signed-off-by: Mark Brown <[email protected]> Link: http://lkml.kernel.org/r/1307037313-15733-1-git-send-email-broonie@opensource.wolfsonmicro.com Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-03genirq: Fix descriptor init on non-sparse IRQsLinus Walleij1-5/+3
The genirq changes are initializing descriptors for sparse IRQs quite differently from how non-sparse (stacked?) IRQs are initialized, with the effect that on my platform all IRQs are default-disabled on sparse IRQs and default-enabled if non-sparse IRQs are used, crashing some GPIO driver. Fix this by refactoring the non-sparse IRQs to use the same descriptor init function as the sparse IRQs. Signed-off: Linus Walleij <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Cc: [email protected] # 2.6.39 Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-03irq: Handle spurios irq detection for threaded irqsSebastian Andrzej Siewior3-16/+36
The detection of spurios interrupts is currently limited to first level handler. In force-threaded mode we never notice if the threaded irq does not feel responsible. This patch catches the return value of the threaded handler and forwards it to the spurious detector. If the primary handler returns only IRQ_WAKE_THREAD then the spourious detector ignores it because it gets called again from the threaded handler. [ tglx: Report the erroneous return value early and bail out ] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-03genirq: Print threaded handler in spurious debug outputSebastian Andrzej Siewior1-4/+5
In forced threaded mode (or with an explicit threaded handler) we only see the primary handler, but not the threaded handler. Signed-off-by: Sebastian Andrzej Siewior <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2011-06-03clockevents: Handle empty cpumask gracefullyThomas Gleixner1-1/+4
For UP it's stupid to request an initialized cpumask for the clock event devices. Though we need the mask set even on UP to avoid a horrible ifdeffery especially in the broadcast code. For SMP we can at least try to survive with a warning and set the cpumask of the cpu we're running on. That gives a decent chance to bring the machine up and retrieve the debug info. Signed-off-by: Thomas Gleixner <[email protected]> Cc: Linus Walleij <[email protected] Cc: Lee Jones <[email protected]> Cc: Russell King - ARM Linux <[email protected]> Cc: Stephen Boyd <[email protected]>
2011-05-31perf, cgroups: Fix up for new APIPeter Zijlstra1-18/+4
Ben changed the cgroup API in commit f780bdb7c1c (cgroups: add per-thread subsystem callbacks) in an incompatible way, but forgot to convert the perf cgroup bits. Avoid compile warnings and runtime splats and convert perf too ;-) Acked-by: Ben Blum <[email protected]> Cc: Stephane Eranian <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/1306767651.1200.2990.camel@twins Signed-off-by: Ingo Molnar <[email protected]>
2011-05-31sched: Fix schedstat.nr_wakeups_migratePeter Zijlstra1-4/+7
While looking over the code I found that with the ttwu rework the nr_wakeups_migrate test broke since we now switch cpus prior to calling ttwu_stat(), hence the test is always true. Cure this by passing the migration state in wake_flags. Also move the whole test under CONFIG_SMP, its hard to migrate tasks on UP :-) Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-05-31sched: Fix cross-cpu clock sync on remote wakeupsPeter Zijlstra1-0/+1
Markus reported that commit 317f394160e ("sched: Move the second half of ttwu() to the remote cpu") caused some accounting funnies on his AMD Phenom II X4, such as weird 'top' results. It turns out that this is due to non-synced TSC and the queued remote wakeups stopped coupeling the two relevant cpu clocks, which leads to wakeups seeing time jumps, which in turn lead to skewed runtime stats. Add an explicit call to sched_clock_cpu() to couple the per-cpu clocks to restore the normal flow of time. Reported-and-tested-by: Markus Trippelsdorf <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/1306835745.2353.3.camel@twins Signed-off-by: Ingo Molnar <[email protected]>
2011-05-31rcu: Cure load woesPeter Zijlstra2-9/+56
Commit cc3ce5176d83 (rcu: Start RCU kthreads in TASK_INTERRUPTIBLE state) fudges a sleeping task' state, resulting in the scheduler seeing a TASK_UNINTERRUPTIBLE task going to sleep, but a TASK_INTERRUPTIBLE task waking up. The result is unbalanced load calculation. The problem that patch tried to address is that the RCU threads could stay in UNINTERRUPTIBLE state for quite a while and triggering the hung task detector due to on-demand wake-ups. Cure the problem differently by always giving the tasks at least one wake-up once the CPU is fully up and running, this will kick them out of the initial UNINTERRUPTIBLE state and into the regular INTERRUPTIBLE wait state. [ The alternative would be teaching kthread_create() to start threads as INTERRUPTIBLE but that needs a tad more thought. ] Reported-by: Damien Wyart <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Acked-by: Paul E. McKenney <[email protected]> Link: http://lkml.kernel.org/r/1306755291.1200.2872.camel@twins Signed-off-by: Ingo Molnar <[email protected]>
2011-05-29mm: Fix boot crash in mm_alloc()Linus Torvalds1-32/+10
Thomas Gleixner reports that we now have a boot crash triggered by CONFIG_CPUMASK_OFFSTACK=y: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c11ae035>] find_next_bit+0x55/0xb0 Call Trace: [<c11addda>] cpumask_any_but+0x2a/0x70 [<c102396b>] flush_tlb_mm+0x2b/0x80 [<c1022705>] pud_populate+0x35/0x50 [<c10227ba>] pgd_alloc+0x9a/0xf0 [<c103a3fc>] mm_init+0xec/0x120 [<c103a7a3>] mm_alloc+0x53/0xd0 which was introduced by commit de03c72cfce5 ("mm: convert mm->cpu_vm_cpumask into cpumask_var_t"), and is due to wrong ordering of mm_init() vs mm_init_cpumask Thomas wrote a patch to just fix the ordering of initialization, but I hate the new double allocation in the fork path, so I ended up instead doing some more radical surgery to clean it all up. Reported-by: Thomas Gleixner <[email protected]> Reported-by: Ingo Molnar <[email protected]> Cc: KOSAKI Motohiro <[email protected]> Cc: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-05-29Merge branch 'idle-release' of ↵Linus Torvalds1-12/+25
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 * 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6: x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param x86 idle: deprecate "no-hlt" cmdline param x86 idle APM: deprecate CONFIG_APM_CPU_IDLE x86 idle floppy: deprecate disable_hlt() x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it x86 idle: clarify AMD erratum 400 workaround idle governor: Avoid lock acquisition to read pm_qos before entering idle cpuidle: menu: fixed wrapping timers at 4.294 seconds
2011-05-29idle governor: Avoid lock acquisition to read pm_qos before entering idleTim Chen1-12/+25
Thanks to the reviews and comments by Rafael, James, Mark and Andi. Here's version 2 of the patch incorporating your comments and also some update to my previous patch comments. I noticed that before entering idle state, the menu idle governor will look up the current pm_qos target value according to the list of qos requests received. This look up currently needs the acquisition of a lock to access the list of qos requests to find the qos target value, slowing down the entrance into idle state due to contention by multiple cpus to access this list. The contention is severe when there are a lot of cpus waking and going into idle. For example, for a simple workload that has 32 pair of processes ping ponging messages to each other, where 64 cpu cores are active in test system, I see the following profile with 37.82% of cpu cycles spent in contention of pm_qos_lock: - 37.82% swapper [kernel.kallsyms] [k] _raw_spin_lock_irqsave - _raw_spin_lock_irqsave - 95.65% pm_qos_request menu_select cpuidle_idle_call - cpu_idle 99.98% start_secondary A better approach will be to cache the updated pm_qos target value so reading it does not require lock acquisition as in the patch below. With this patch the contention for pm_qos_lock is removed and I saw a 2.2X increase in throughput for my message passing workload. cc: [email protected] Signed-off-by: Tim Chen <[email protected]> Acked-by: Andi Kleen <[email protected]> Acked-by: James Bottomley <[email protected]> Acked-by: mark gross <[email protected]> Signed-off-by: Len Brown <[email protected]>
2011-05-28Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds6-26/+57
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed sched: Fix ->min_vruntime calculation in dequeue_entity() sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSW sched: More sched_domain iterations fixes
2011-05-28Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds4-136/+94
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Start RCU kthreads in TASK_INTERRUPTIBLE state rcu: Remove waitqueue usage for cpu, node, and boost kthreads rcu: Avoid acquiring rcu_node locks in timer functions atomic: Add atomic_or() Documentation: Add statistics about nested locks rcu: Decrease memory-barrier usage based on semi-formal proof rcu: Make rcu_enter_nohz() pay attention to nesting rcu: Don't do reschedule unless in irq rcu: Remove old memory barriers from rcu_process_callbacks() rcu: Add memory barriers rcu: Fix unpaired rcu_irq_enter() from locking selftests
2011-05-28Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds8-24/+101
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits) perf: Fix SIGIO handling perf top: Don't stop if no kernel symtab is found perf top: Handle kptr_restrict perf top: Remove unused macro perf events: initialize fd array to -1 instead of 0 perf tools: Make sure kptr_restrict warnings fit 80 col terms perf tools: Fix build on older systems perf symbols: Handle /proc/sys/kernel/kptr_restrict perf: Remove duplicate headers ftrace: Add internal recursive checks tracing: Update btrfs's tracepoints to use u64 interface tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine ftrace: Set ops->flag to enabled even on static function tracing tracing: Have event with function tracer check error return ftrace: Have ftrace_startup() return failure code jump_label: Check entries limit in __jump_label_update ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM scripts/tags.sh: Add magic for trace-events for etags too scripts/tags.sh: Fix ctags for DEFINE_EVENT() x86/ftrace: Fix compiler warning in ftrace.c ...
2011-05-28rcu: Start RCU kthreads in TASK_INTERRUPTIBLE statePaul E. McKenney2-0/+3
Upon creation, kthreads are in TASK_UNINTERRUPTIBLE state, which can result in softlockup warnings. Because some of RCU's kthreads can legitimately be idle indefinitely, start them in TASK_INTERRUPTIBLE state in order to avoid those warnings. Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Tested-by: Yinghai Lu <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28rcu: Remove waitqueue usage for cpu, node, and boost kthreadsPeter Zijlstra3-39/+17
It is not necessary to use waitqueues for the RCU kthreads because we always know exactly which thread is to be awakened. In addition, wake_up() only issues an actual wakeup when there is a thread waiting on the queue, which was why there was an extra explicit wake_up_process() to get the RCU kthreads started. Eliminating the waitqueues (and wake_up()) in favor of wake_up_process() eliminates the need for the initial wake_up_process() and also shrinks the data structure size a bit. The wakeup logic is placed in a new rcu_wait() macro. Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28rcu: Avoid acquiring rcu_node locks in timer functionsPaul E. McKenney2-9/+8
This commit switches manipulations of the rcu_node ->wakemask field to atomic operations, which allows rcu_cpu_kthread_timer() to avoid acquiring the rcu_node lock. This should avoid the following lockdep splat reported by Valdis Kletnieks: [ 12.872150] usb 1-4: new high speed USB device number 3 using ehci_hcd [ 12.986667] usb 1-4: New USB device found, idVendor=413c, idProduct=2513 [ 12.986679] usb 1-4: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 12.987691] hub 1-4:1.0: USB hub found [ 12.987877] hub 1-4:1.0: 3 ports detected [ 12.996372] input: PS/2 Generic Mouse as /devices/platform/i8042/serio1/input/input10 [ 13.071471] udevadm used greatest stack depth: 3984 bytes left [ 13.172129] [ 13.172130] ======================================================= [ 13.172425] [ INFO: possible circular locking dependency detected ] [ 13.172650] 2.6.39-rc6-mmotm0506 #1 [ 13.172773] ------------------------------------------------------- [ 13.172997] blkid/267 is trying to acquire lock: [ 13.173009] (&p->pi_lock){-.-.-.}, at: [<ffffffff81032d8f>] try_to_wake_up+0x29/0x1aa [ 13.173009] [ 13.173009] but task is already holding lock: [ 13.173009] (rcu_node_level_0){..-...}, at: [<ffffffff810901cc>] rcu_cpu_kthread_timer+0x27/0x58 [ 13.173009] [ 13.173009] which lock already depends on the new lock. [ 13.173009] [ 13.173009] [ 13.173009] the existing dependency chain (in reverse order) is: [ 13.173009] [ 13.173009] -> #2 (rcu_node_level_0){..-...}: [ 13.173009] [<ffffffff810679b9>] check_prevs_add+0x8b/0x104 [ 13.173009] [<ffffffff81067da1>] validate_chain+0x36f/0x3ab [ 13.173009] [<ffffffff8106846b>] __lock_acquire+0x369/0x3e2 [ 13.173009] [<ffffffff81068a0f>] lock_acquire+0xfc/0x14c [ 13.173009] [<ffffffff815697f1>] _raw_spin_lock+0x36/0x45 [ 13.173009] [<ffffffff81090794>] rcu_read_unlock_special+0x8c/0x1d5 [ 13.173009] [<ffffffff8109092c>] __rcu_read_unlock+0x4f/0xd7 [ 13.173009] [<ffffffff81027bd3>] rcu_read_unlock+0x21/0x23 [ 13.173009] [<ffffffff8102cc34>] cpuacct_charge+0x6c/0x75 [ 13.173009] [<ffffffff81030cc6>] update_curr+0x101/0x12e [ 13.173009] [<ffffffff810311d0>] check_preempt_wakeup+0xf7/0x23b [ 13.173009] [<ffffffff8102acb3>] check_preempt_curr+0x2b/0x68 [ 13.173009] [<ffffffff81031d40>] ttwu_do_wakeup+0x76/0x128 [ 13.173009] [<ffffffff81031e49>] ttwu_do_activate.constprop.63+0x57/0x5c [ 13.173009] [<ffffffff81031e96>] scheduler_ipi+0x48/0x5d [ 13.173009] [<ffffffff810177d5>] smp_reschedule_interrupt+0x16/0x18 [ 13.173009] [<ffffffff815710f3>] reschedule_interrupt+0x13/0x20 [ 13.173009] [<ffffffff810b66d1>] rcu_read_unlock+0x21/0x23 [ 13.173009] [<ffffffff810b739c>] find_get_page+0xa9/0xb9 [ 13.173009] [<ffffffff810b8b48>] filemap_fault+0x6a/0x34d [ 13.173009] [<ffffffff810d1a25>] __do_fault+0x54/0x3e6 [ 13.173009] [<ffffffff810d447a>] handle_pte_fault+0x12c/0x1ed [ 13.173009] [<ffffffff810d48f7>] handle_mm_fault+0x1cd/0x1e0 [ 13.173009] [<ffffffff8156cfee>] do_page_fault+0x42d/0x5de [ 13.173009] [<ffffffff8156a75f>] page_fault+0x1f/0x30 [ 13.173009] [ 13.173009] -> #1 (&rq->lock){-.-.-.}: [ 13.173009] [<ffffffff810679b9>] check_prevs_add+0x8b/0x104 [ 13.173009] [<ffffffff81067da1>] validate_chain+0x36f/0x3ab [ 13.173009] [<ffffffff8106846b>] __lock_acquire+0x369/0x3e2 [ 13.173009] [<ffffffff81068a0f>] lock_acquire+0xfc/0x14c [ 13.173009] [<ffffffff815697f1>] _raw_spin_lock+0x36/0x45 [ 13.173009] [<ffffffff81027e19>] __task_rq_lock+0x8b/0xd3 [ 13.173009] [<ffffffff81032f7f>] wake_up_new_task+0x41/0x108 [ 13.173009] [<ffffffff810376c3>] do_fork+0x265/0x33f [ 13.173009] [<ffffffff81007d02>] kernel_thread+0x6b/0x6d [ 13.173009] [<ffffffff8153a9dd>] rest_init+0x21/0xd2 [ 13.173009] [<ffffffff81b1db4f>] start_kernel+0x3bb/0x3c6 [ 13.173009] [<ffffffff81b1d29f>] x86_64_start_reservations+0xaf/0xb3 [ 13.173009] [<ffffffff81b1d393>] x86_64_start_kernel+0xf0/0xf7 [ 13.173009] [ 13.173009] -> #0 (&p->pi_lock){-.-.-.}: [ 13.173009] [<ffffffff81067788>] check_prev_add+0x68/0x20e [ 13.173009] [<ffffffff810679b9>] check_prevs_add+0x8b/0x104 [ 13.173009] [<ffffffff81067da1>] validate_chain+0x36f/0x3ab [ 13.173009] [<ffffffff8106846b>] __lock_acquire+0x369/0x3e2 [ 13.173009] [<ffffffff81068a0f>] lock_acquire+0xfc/0x14c [ 13.173009] [<ffffffff815698ea>] _raw_spin_lock_irqsave+0x44/0x57 [ 13.173009] [<ffffffff81032d8f>] try_to_wake_up+0x29/0x1aa [ 13.173009] [<ffffffff81032f3c>] wake_up_process+0x10/0x12 [ 13.173009] [<ffffffff810901e9>] rcu_cpu_kthread_timer+0x44/0x58 [ 13.173009] [<ffffffff81045286>] call_timer_fn+0xac/0x1e9 [ 13.173009] [<ffffffff8104556d>] run_timer_softirq+0x1aa/0x1f2 [ 13.173009] [<ffffffff8103e487>] __do_softirq+0x109/0x26a [ 13.173009] [<ffffffff8157144c>] call_softirq+0x1c/0x30 [ 13.173009] [<ffffffff81003207>] do_softirq+0x44/0xf1 [ 13.173009] [<ffffffff8103e8b9>] irq_exit+0x58/0xc8 [ 13.173009] [<ffffffff81017f5a>] smp_apic_timer_interrupt+0x79/0x87 [ 13.173009] [<ffffffff81570fd3>] apic_timer_interrupt+0x13/0x20 [ 13.173009] [<ffffffff810bd51a>] get_page_from_freelist+0x2aa/0x310 [ 13.173009] [<ffffffff810bdf03>] __alloc_pages_nodemask+0x178/0x243 [ 13.173009] [<ffffffff8101fe2f>] pte_alloc_one+0x1e/0x3a [ 13.173009] [<ffffffff810d27fe>] __pte_alloc+0x22/0x14b [ 13.173009] [<ffffffff810d48a8>] handle_mm_fault+0x17e/0x1e0 [ 13.173009] [<ffffffff8156cfee>] do_page_fault+0x42d/0x5de [ 13.173009] [<ffffffff8156a75f>] page_fault+0x1f/0x30 [ 13.173009] [ 13.173009] other info that might help us debug this: [ 13.173009] [ 13.173009] Chain exists of: [ 13.173009] &p->pi_lock --> &rq->lock --> rcu_node_level_0 [ 13.173009] [ 13.173009] Possible unsafe locking scenario: [ 13.173009] [ 13.173009] CPU0 CPU1 [ 13.173009] ---- ---- [ 13.173009] lock(rcu_node_level_0); [ 13.173009] lock(&rq->lock); [ 13.173009] lock(rcu_node_level_0); [ 13.173009] lock(&p->pi_lock); [ 13.173009] [ 13.173009] *** DEADLOCK *** [ 13.173009] [ 13.173009] 3 locks held by blkid/267: [ 13.173009] #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8156cdb4>] do_page_fault+0x1f3/0x5de [ 13.173009] #1: (&yield_timer){+.-...}, at: [<ffffffff810451da>] call_timer_fn+0x0/0x1e9 [ 13.173009] #2: (rcu_node_level_0){..-...}, at: [<ffffffff810901cc>] rcu_cpu_kthread_timer+0x27/0x58 [ 13.173009] [ 13.173009] stack backtrace: [ 13.173009] Pid: 267, comm: blkid Not tainted 2.6.39-rc6-mmotm0506 #1 [ 13.173009] Call Trace: [ 13.173009] <IRQ> [<ffffffff8154a529>] print_circular_bug+0xc8/0xd9 [ 13.173009] [<ffffffff81067788>] check_prev_add+0x68/0x20e [ 13.173009] [<ffffffff8100c861>] ? save_stack_trace+0x28/0x46 [ 13.173009] [<ffffffff810679b9>] check_prevs_add+0x8b/0x104 [ 13.173009] [<ffffffff81067da1>] validate_chain+0x36f/0x3ab [ 13.173009] [<ffffffff8106846b>] __lock_acquire+0x369/0x3e2 [ 13.173009] [<ffffffff81032d8f>] ? try_to_wake_up+0x29/0x1aa [ 13.173009] [<ffffffff81068a0f>] lock_acquire+0xfc/0x14c [ 13.173009] [<ffffffff81032d8f>] ? try_to_wake_up+0x29/0x1aa [ 13.173009] [<ffffffff810901a5>] ? rcu_check_quiescent_state+0x82/0x82 [ 13.173009] [<ffffffff815698ea>] _raw_spin_lock_irqsave+0x44/0x57 [ 13.173009] [<ffffffff81032d8f>] ? try_to_wake_up+0x29/0x1aa [ 13.173009] [<ffffffff81032d8f>] try_to_wake_up+0x29/0x1aa [ 13.173009] [<ffffffff810901a5>] ? rcu_check_quiescent_state+0x82/0x82 [ 13.173009] [<ffffffff81032f3c>] wake_up_process+0x10/0x12 [ 13.173009] [<ffffffff810901e9>] rcu_cpu_kthread_timer+0x44/0x58 [ 13.173009] [<ffffffff810901a5>] ? rcu_check_quiescent_state+0x82/0x82 [ 13.173009] [<ffffffff81045286>] call_timer_fn+0xac/0x1e9 [ 13.173009] [<ffffffff810451da>] ? del_timer+0x75/0x75 [ 13.173009] [<ffffffff810901a5>] ? rcu_check_quiescent_state+0x82/0x82 [ 13.173009] [<ffffffff8104556d>] run_timer_softirq+0x1aa/0x1f2 [ 13.173009] [<ffffffff8103e487>] __do_softirq+0x109/0x26a [ 13.173009] [<ffffffff8106365f>] ? tick_dev_program_event+0x37/0xf6 [ 13.173009] [<ffffffff810a0e4a>] ? time_hardirqs_off+0x1b/0x2f [ 13.173009] [<ffffffff8157144c>] call_softirq+0x1c/0x30 [ 13.173009] [<ffffffff81003207>] do_softirq+0x44/0xf1 [ 13.173009] [<ffffffff8103e8b9>] irq_exit+0x58/0xc8 [ 13.173009] [<ffffffff81017f5a>] smp_apic_timer_interrupt+0x79/0x87 [ 13.173009] [<ffffffff81570fd3>] apic_timer_interrupt+0x13/0x20 [ 13.173009] <EOI> [<ffffffff810bd384>] ? get_page_from_freelist+0x114/0x310 [ 13.173009] [<ffffffff810bd51a>] ? get_page_from_freelist+0x2aa/0x310 [ 13.173009] [<ffffffff812220e7>] ? clear_page_c+0x7/0x10 [ 13.173009] [<ffffffff810bd1ef>] ? prep_new_page+0x14c/0x1cd [ 13.173009] [<ffffffff810bd51a>] get_page_from_freelist+0x2aa/0x310 [ 13.173009] [<ffffffff810bdf03>] __alloc_pages_nodemask+0x178/0x243 [ 13.173009] [<ffffffff810d46b9>] ? __pmd_alloc+0x87/0x99 [ 13.173009] [<ffffffff8101fe2f>] pte_alloc_one+0x1e/0x3a [ 13.173009] [<ffffffff810d46b9>] ? __pmd_alloc+0x87/0x99 [ 13.173009] [<ffffffff810d27fe>] __pte_alloc+0x22/0x14b [ 13.173009] [<ffffffff810d48a8>] handle_mm_fault+0x17e/0x1e0 [ 13.173009] [<ffffffff8156cfee>] do_page_fault+0x42d/0x5de [ 13.173009] [<ffffffff810d915f>] ? sys_brk+0x32/0x10c [ 13.173009] [<ffffffff810a0e4a>] ? time_hardirqs_off+0x1b/0x2f [ 13.173009] [<ffffffff81065c4f>] ? trace_hardirqs_off_caller+0x3f/0x9c [ 13.173009] [<ffffffff812235dd>] ? trace_hardirqs_off_thunk+0x3a/0x3c [ 13.173009] [<ffffffff8156a75f>] page_fault+0x1f/0x30 [ 14.010075] usb 5-1: new full speed USB device number 2 using uhci_hcd Reported-by: Valdis Kletnieks <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28Merge branch 'rcu/urgent' of ↵Ingo Molnar4-90/+68
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/urgent
2011-05-28perf: Fix SIGIO handlingPeter Zijlstra1-0/+8
Vince noticed that unless we mmap() a buffer, SIGIO gets lost. So explicitly push the wakeup (including signals) when requested. Reported-by: Vince Weaver <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowedKOSAKI Motohiro3-11/+16
The rule is, we have to update tsk->rt.nr_cpus_allowed if we change tsk->cpus_allowed. Otherwise RT scheduler may confuse. Signed-off-by: KOSAKI Motohiro <[email protected]> Cc: Oleg Nesterov <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28sched: Fix ->min_vruntime calculation in dequeue_entity()Peter Zijlstra1-2/+3
Dima Zavin <[email protected]> reported: "After pulling the thread off the run-queue during a cgroup change, the cfs_rq.min_vruntime gets recalculated. The dequeued thread's vruntime then gets normalized to this new value. This can then lead to the thread getting an unfair boost in the new group if the vruntime of the next task in the old run-queue was way further ahead." Reported-by: Dima Zavin <[email protected]> Signed-off-by: John Stultz <[email protected]> Recalls-having-tested-once-upon-a-time-by: Mike Galbraith <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28sched: Fix ttwu() for __ARCH_WANT_INTERRUPTS_ON_CTXSWPeter Zijlstra1-9/+28
Marc reported that e4a52bcb9 (sched: Remove rq->lock from the first half of ttwu()) broke his ARM-SMP machine. Now ARM is one of the few __ARCH_WANT_INTERRUPTS_ON_CTXSW users, so that exception in the ttwu() code was suspect. Yong found that the interrupt could hit after context_switch() changes current but before it clears p->on_cpu, if that interrupt were to attempt a wake-up of p we would indeed find ourselves spinning in IRQ context. Fix this by reverting to the old behaviour for this situation and perform a full remote wake-up. Cc: Frank Rowand <[email protected]> Cc: Yong Zhang <[email protected]> Cc: Oleg Nesterov <[email protected]> Reported-by: Marc Zyngier <[email protected]> Tested-by: Marc Zyngier <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
2011-05-28sched: More sched_domain iterations fixesXiaotian Feng2-4/+10
sched_domain iterations needs to be protected by rcu_read_lock() now, this patch adds another two places which needs the rcu lock, which is spotted by following suspicious rcu_dereference_check() usage warnings. kernel/sched_rt.c:1244 invoked rcu_dereference_check() without protection! kernel/sched_stats.h:41 invoked rcu_dereference_check() without protection! Signed-off-by: Xiaotian Feng <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2011-05-27Merge branch 'for-linus' of ↵Linus Torvalds2-119/+134
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6: PM: Fix PM QOS's user mode interface to work with ASCII input PM / Hibernate: Update kerneldoc comments in hibernate.c PM / Hibernate: Remove arch_prepare_suspend() PM / Hibernate: Update some comments in core hibernate code
2011-05-27Merge branch 'docs-move' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs * 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs: Create Documentation/security/, move LSM-, credentials-, and keys-related files from Documentation/ to Documentation/security/, add Documentation/security/00-INDEX, and update all occurrences of Documentation/<moved_file> to Documentation/security/<moved_file>.
2011-05-27Merge branch 'tip/perf/urgent' of ↵Ingo Molnar6-18/+90
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
2011-05-26kernel/profile.c: remove some duplicate code from profile_hits()Rakib Mullick1-7/+9
profile_hits() has a common check for prof_on and prof_buffer regardless of SMP or !SMP. So, remove some duplicate code by splitting profile_hits into two. [[email protected]: make do_profile_hits static] Signed-off-by: Rakib Mullick <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-05-26mm: extract exe_file handling from procfsJiri Slaby1-1/+51
Setup and cleanup of mm_struct->exe_file is currently done in fs/proc/. This was because exe_file was needed only for /proc/<pid>/exe. Since we will need the exe_file functionality also for core dumps (so core name can contain full binary path), built this functionality always into the kernel. To achieve that move that out of proc FS to the kernel/ where in fact it should belong. By doing that we can make dup_mm_exe_file static. Also we can drop linux/proc_fs.h inclusion in fs/exec.c and kernel/fork.c. Signed-off-by: Jiri Slaby <[email protected]> Cc: Alexander Viro <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-05-26cgroup: remove the ns_cgroupDaniel Lezcano6-249/+3
The ns_cgroup is an annoying cgroup at the namespace / cgroup frontier and leads to some problems: * cgroup creation is out-of-control * cgroup name can conflict when pids are looping * it is not possible to have a single process handling a lot of namespaces without falling in a exponential creation time * we may want to create a namespace without creating a cgroup The ns_cgroup was replaced by a compatibility flag 'clone_children', where a newly created cgroup will copy the parent cgroup values. The userspace has to manually create a cgroup and add a task to the 'tasks' file. This patch removes the ns_cgroup as suggested in the following thread: https://lists.linux-foundation.org/pipermail/containers/2009-June/018616.html The 'cgroup_clone' function is removed because it is no longer used. This is a userspace-visible change. Commit 45531757b45c ("cgroup: notify ns_cgroup deprecated") (merged into 2.6.27) caused the kernel to emit a printk warning users that the feature is planned for removal. Since that time we have heard from XXX users who were affected by this. Signed-off-by: Daniel Lezcano <[email protected]> Signed-off-by: Serge E. Hallyn <[email protected]> Cc: Eric W. Biederman <[email protected]> Cc: Jamal Hadi Salim <[email protected]> Reviewed-by: Li Zefan <[email protected]> Acked-by: Paul Menage <[email protected]> Acked-by: Matt Helsley <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2011-05-26cgroups: use flex_array in attach_procBen Blum1-9/+24
Convert cgroup_attach_proc to use flex_array. The cgroup_attach_proc implementation requires a pre-allocated array to store task pointers to atomically move a thread-group, but asking for a monolithic array with kmalloc() may be unreliable for very large groups. Using flex_array provides the same functionality with less risk of failure. This is a post-patch for cgroup-procs-write.patch. Signed-off-by: Ben Blum <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: Li Zefan <[email protected]> Cc: Matt Helsley <[email protected]> Reviewed-by: Paul Menage <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: David Rientjes <[email protected]> Cc: Miao Xie <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
Powered by cgit, Gruvboxed by Blaster4385.