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| * | stop_machine: remove unused variableLi Zefan2008-08-121-1/+0
| | | | | | | | | | | | | | | Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | modules: extend initcall_debug functionality to the module loaderArjan van de Ven2008-08-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel has this really nice facility where if you put "initcall_debug" on the kernel commandline, it'll print which function it's going to execute just before calling an initcall, and then after the call completes it will 1) print if it had an error code 2) checks for a few simple bugs (like leaving irqs off) and 3) print how long the init call took in milliseconds. While trying to optimize the boot speed of my laptop, I have been loving number 3 to figure out what to optimize... ... and then I wished that the same thing was done for module loading. This patch makes the module loader use this exact same functionality; it's a logical extension in my view (since modules are just sort of late binding initcalls anyway) and so far I've found it quite useful in finding where things are too slow in my boot. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2008-08-116-137/+73
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacks sched: fix mysql+oltp regression sched_clock: delay using sched_clock() sched clock: couple local and remote clocks sched clock: simplify __update_sched_clock() sched: eliminate scd->prev_raw sched clock: clean up sched_clock_cpu() sched clock: revert various sched_clock() changes sched: move sched_clock before first use sched: test runtime rather than period in global_rt_runtime() sched: fix SCHED_HRTICK dependency sched: fix warning in hrtick_start_fair()
| * \ \ Merge branch 'sched/clock' into sched/urgentIngo Molnar2008-08-122-116/+49
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| | * \ \ Merge branch 'linus' into sched/clockIngo Molnar2008-08-1118-125/+239
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| | * | | | sched_clock: delay using sched_clock()Peter Zijlstra2008-08-111-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some arch's can't handle sched_clock() being called too early - delay this until sched_clock_init() has been called. Reported-by: Bill Gatliff <bgat@billgatliff.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Nishanth Aravamudan <nacc@us.ibm.com> CC: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | sched clock: couple local and remote clocksIngo Molnar2008-07-311-12/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When taking the time of a remote CPU, use the opportunity to couple (sync) the clocks to each other. (in a monotonic way) Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: simplify __update_sched_clock()Ingo Molnar2008-07-311-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - return the current clock instead of letting callers fetch it from scd->clock Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched: eliminate scd->prev_rawIngo Molnar2008-07-311-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | eliminate prev_raw and use tick_raw instead. It's enough to base the current time on the scheduler tick timestamp alone - the monotonicity and maximum checks will prevent any damage. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: clean up sched_clock_cpu()Ingo Molnar2008-07-311-5/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - simplify the remote clock rebasing Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | sched clock: revert various sched_clock() changesIngo Molnar2008-07-312-98/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Found an interactivity problem on a quad core test-system - simple CPU loops would occasionally delay the system un an unacceptable way. After much debugging with Peter Zijlstra it turned out that the problem is caused by the string of sched_clock() changes - they caused the CPU clock to jump backwards a bit - which confuses the scheduler arithmetics. (which is unsigned for performance reasons) So revert: # c300ba2: sched_clock: and multiplier for TSC to gtod drift # c0c8773: sched_clock: only update deltas with local reads. # af52a90: sched_clock: stop maximum check on NO HZ # f7cce27: sched_clock: widen the max and min time This solves the interactivity problems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
| | * | | | Merge branch 'sched/urgent' into sched/clockIngo Molnar2008-07-304-13/+12
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| * | | | | | sched, cpu hotplug: fix set_cpus_allowed() use in hotplug callbacksDmitry Adamushko2008-08-111-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark Langsdorf reported: > One of my co-workers noticed that the powernow-k8 > driver no longer restarts when a CPU core is > hot-disabled and then hot-enabled on AMD quad-core > systems. > > The following comands work fine on 2.6.26 and fail > on 2.6.27-rc1: > > echo 0 > /sys/devices/system/cpu/cpu3/online > echo 1 > /sys/devices/system/cpu/cpu3/online > find /sys -name cpufreq > > For 2.6.26, the find will return a cpufreq > directory for each processor. In 2.6.27-rc1, > the cpu3 directory is missing. > > After digging through the code, the following > logic is failing when the core is hot-enabled > at runtime. The code works during the boot > sequence. > > cpumask_t = current->cpus_allowed; > set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); > if (smp_processor_id() != cpu) > return -ENODEV; So set the CPU active before calling the CPU_ONLINE notifier chain, there are a handful of notifiers that use set_cpus_allowed(). This fix also solves the problem with x86-microcode. I've sent alternative patches for microcode, but as this "rely on set_cpus_allowed_ptr() being workable in cpu-hotplug(CPU_ONLINE, ...)" assumption seems to be more broad than what we thought, perhaps this fix should be applied. With this patch we define that by the moment CPU_ONLINE is being sent, a 'cpu' is online and ready for tasks to be migrated onto it. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Reported-by: Mark Langsdorf <mark.langsdorf@amd.com> Tested-by: Mark Langsdorf <mark.langsdorf@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | sched: fix mysql+oltp regressionMike Galbraith2008-08-111-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Defer commit 6d299f1b53b84e2665f402d9bcc494800aba6386 to the next release. Testing of the tip/sched/clock tree revealed a mysql+oltp regression which bisection eventually traced back to this commit in mainline. Pertinent test results: Three run sysbench averages, throughput units in read/write requests/sec. clients 1 2 4 8 16 32 64 6e0534f 9646 17876 34774 33868 32230 30767 29441 2.6.26.1 9112 17936 34652 33383 31929 30665 29232 6d299f1 9112 14637 28370 33339 32038 30762 29204 Note: subsequent commits hide the majority of this regression until you apply the clock fixes, at which time it reemerges at full magnitude. We cannot see anything bad about the change itself so we defer it to the next release until this problem is fully analysed. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | Merge branch 'linus' into sched/urgentIngo Molnar2008-08-1118-125/+239
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| * | | | | | Merge branch 'linus' into sched/urgentIngo Molnar2008-07-3110-197/+345
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| * | | | | sched: move sched_clock before first useHugh Dickins2008-07-281-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move sched_clock() up to stop warning: weak declaration of `sched_clock' after first use results in unspecified behavior (if -fno-unit-at-a-time). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Mike Travis <travis@sgi.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Linuxppc-dev@ozlabs.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: test runtime rather than period in global_rt_runtime()roel kluin2008-07-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test runtime rather than period Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: fix SCHED_HRTICK dependencyOGAWA Hirofumi2008-07-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, it seems SCHED_HRTICK allowed for !SMP. But, it seems to have no dependency of it. Fix it. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: fix warning in hrtick_start_fair()Peter Zijlstra2008-07-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Benjamin Herrenschmidt reported: > I get that on ppc64 ... > > In file included from kernel/sched.c:1595: > kernel/sched_fair.c: In function ‘hrtick_start_fair’: > kernel/sched_fair.c:902: warning: comparison of distinct pointer types lacks a cast > > Probably harmless but annoying. s64 delta = slice - ran; --> delta = max(10000LL, delta); Probably ppc64's s64 is long vs long long.. I think hpa was looking at sanitizing all these 64bit types across the architectures. Use max_t with an explicit type meanwhile. Reported-by: Benjamin Herrenschmid <benh@kernel.crashing.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2008-08-112-5/+15
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: posix-timers: fix posix_timer_event() vs dequeue_signal() race posix-timers: do_schedule_next_timer: fix the setting of ->si_overrun
| * \ \ \ \ \ Merge branch 'timers/urgent' of ↵Ingo Molnar2008-07-272-5/+15
| |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | ssh://master.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into timers/urgent
| | * | | | | | posix-timers: fix posix_timer_event() vs dequeue_signal() raceOleg Nesterov2008-07-242-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bug was reported and analysed by Mark McLoughlin <markmc@redhat.com>, the patch is based on his and Roland's suggestions. posix_timer_event() always rewrites the pre-allocated siginfo before sending the signal. Most of the written info is the same all the time, but memset(0) is very wrong. If ->sigq is queued we can race with collect_signal() which can fail to find this siginfo looking at .si_signo, or copy_siginfo() can copy the wrong .si_code/si_tid/etc. In short, sys_timer_settime() can in fact stop the active timer, or the user can receive the siginfo with the wrong .si_xxx values. Move "memset(->info, 0)" from posix_timer_event() to alloc_posix_timer(), change send_sigqueue() to set .si_overrun = 0 when ->sigq is not queued. It would be nice to move the whole sigq->info initialization from send to create path, but this is not easy to do without uglifying timer_create() further. As Roland rightly pointed out, we need more cleanups/fixes here, see the "FIXME" comment in the patch. Hopefully this patch makes sense anyway, and it can mask the most bad implications. Reported-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Oliver Pinter <oliver.pntr@gmail.com> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> kernel/posix-timers.c | 17 +++++++++++++---- kernel/signal.c | 1 + 2 files changed, 14 insertions(+), 4 deletions(-)
| | * | | | | | posix-timers: do_schedule_next_timer: fix the setting of ->si_overrunOleg Nesterov2008-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_schedule_next_timer() sets info->si_overrun = timr->it_overrun_last, this discards the already accumulated overruns. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Mark McLoughlin <markmc@redhat.com> Cc: Oliver Pinter <oliver.pntr@gmail.com> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2008-08-118-120/+336
|\ \ \ \ \ \ \ \ | |_|_|_|_|_|/ / |/| | | | | | / | | |_|_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: lockdep: fix debug_lock_alloc lockdep: increase MAX_LOCKDEP_KEYS generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask() lockdep: fix overflow in the hlock shrinkage code lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]() lockdep: handle chains involving classes defined in modules mm: fix mm_take_all_locks() locking order lockdep: annotate mm_take_all_locks() lockdep: spin_lock_nest_lock() lockdep: lock protection locks lockdep: map_acquire lockdep: shrink held_lock structure lockdep: re-annotate scheduler runqueues lockdep: lock_set_subclass - reset a held lock's subclass lockdep: change scheduler annotation debug_locks: set oops_in_progress if we will log messages. lockdep: fix combinatorial explosion in lock subgraph traversal
| * | | | | | Merge branch 'core/locking' into core/urgentIngo Molnar2008-08-127-113/+289
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| | * | | | | | lockdep: fix debug_lock_allocPeter Zijlstra2008-08-111-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we enable DEBUG_LOCK_ALLOC but do not enable PROVE_LOCKING and or LOCK_STAT, lock_alloc() and lock_release() turn into nops, even though we should be doing hlock checking (check=1). This causes a false warning and a lockdep self-disable. Rectify this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: rename map_[acquire|release]() => lock_map_[acquire|release]()Ingo Molnar2008-08-111-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | the names were too generic: drivers/uio/uio.c:87: error: expected identifier or '(' before 'do' drivers/uio/uio.c:87: error: expected identifier or '(' before 'while' drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function) Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: handle chains involving classes defined in modulesRabin Vincent2008-08-112-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Solve this by marking the classes as unused and not printing information about the unused classes. Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: spin_lock_nest_lock()Peter Zijlstra2008-08-111-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Expose the new lock protection lock. This can be used to annotate places where we take multiple locks of the same class and avoid deadlocks by always taking another (top-level) lock first. NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: lock protection locksPeter Zijlstra2008-08-111-5/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote: > On Fri, 1 Aug 2008, David Miller wrote: > > > > Taking more than a few locks of the same class at once is bad > > news and it's better to find an alternative method. > > It's not always wrong. > > If you can guarantee that anybody that takes more than one lock of a > particular class will always take a single top-level lock _first_, then > that's all good. You can obviously screw up and take the same lock _twice_ > (which will deadlock), but at least you cannot get into ABBA situations. > > So maybe the right thing to do is to just teach lockdep about "lock > protection locks". That would have solved the multi-queue issues for > networking too - all the actual network drivers would still have taken > just their single queue lock, but the one case that needs to take all of > them would have taken a separate top-level lock first. > > Never mind that the multi-queue locks were always taken in the same order: > it's never wrong to just have some top-level serialization, and anybody > who needs to take <n> locks might as well do <n+1>, because they sure as > hell aren't going to be on _any_ fastpaths. > > So the simplest solution really sounds like just teaching lockdep about > that one special case. It's not "nesting" exactly, although it's obviously > related to it. Do as Linus suggested. The lock protection lock is called nest_lock. Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything that spills that it still up shit creek. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: map_acquirePeter Zijlstra2008-08-111-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most the free-standing lock_acquire() usages look remarkably similar, sweep them into a new helper. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: shrink held_lock structureDave Jones2008-08-112-51/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct held_lock { u64 prev_chain_key; /* 0 8 */ struct lock_class * class; /* 8 8 */ long unsigned int acquire_ip; /* 16 8 */ struct lockdep_map * instance; /* 24 8 */ int irq_context; /* 32 4 */ int trylock; /* 36 4 */ int read; /* 40 4 */ int check; /* 44 4 */ int hardirqs_off; /* 48 4 */ /* size: 56, cachelines: 1 */ /* padding: 4 */ /* last cacheline: 56 bytes */ }; struct held_lock { u64 prev_chain_key; /* 0 8 */ long unsigned int acquire_ip; /* 8 8 */ struct lockdep_map * instance; /* 16 8 */ unsigned int class_idx:11; /* 24:21 4 */ unsigned int irq_context:2; /* 24:19 4 */ unsigned int trylock:1; /* 24:18 4 */ unsigned int read:2; /* 24:16 4 */ unsigned int check:2; /* 24:14 4 */ unsigned int hardirqs_off:1; /* 24:13 4 */ /* size: 32, cachelines: 1 */ /* padding: 4 */ /* bit_padding: 13 bits */ /* last cacheline: 32 bytes */ }; [mingo@elte.hu: shrunk hlock->class too] [peterz@infradead.org: fixup bit sizes] Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
| | * | | | | | lockdep: re-annotate scheduler runqueuesPeter Zijlstra2008-08-112-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using a per-rq lock class, use the regular nesting operations. However, take extra care with double_lock_balance() as it can release the already held rq->lock (and therefore change its nesting class). So what can happen is: spin_lock(rq->lock); // this rq subclass 0 double_lock_balance(rq, other_rq); // release rq // acquire other_rq->lock subclass 0 // acquire rq->lock subclass 1 spin_unlock(other_rq->lock); leaving you with rq->lock in subclass 1 So a subsequent double_lock_balance() call can try to nest a subclass 1 lock while already holding a subclass 1 lock. Fix this by introducing double_unlock_balance() which releases the other rq's lock, but also re-sets the subclass for this rq's lock to 0. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: lock_set_subclass - reset a held lock's subclassPeter Zijlstra2008-08-111-0/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | this can be used to reset a held lock's subclass, for arbitrary-depth iterated data structures such as trees or lists which have per-node locks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: change scheduler annotationPeter Zijlstra2008-08-011-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While thinking about David's graph walk lockdep patch it _finally_ dawned on me that there is no reason we have a lock class per cpu ... Sorry for being dense :-/ The below changes the annotation from a lock class per cpu, to a single nested lock, as the scheduler never holds more that 2 rq locks at a time anyway. If there was code requiring holding all rq locks this would not work and the original annotation would be the only option, but that not being the case, this is a much lighter one. Compiles and boots on a 2-way x86_64. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: David Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | lockdep: fix combinatorial explosion in lock subgraph traversalDavid Miller2008-07-313-31/+92
| | | |_|_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we traverse the graph, either forwards or backwards, we are interested in whether a certain property exists somewhere in a node reachable in the graph. Therefore it is never necessary to traverse through a node more than once to get a correct answer to the given query. Take advantage of this property using a global ID counter so that we need not clear all the markers in all the lock_class entries before doing a traversal. A new ID is choosen when we start to traverse, and we continue through a lock_class only if it's ID hasn't been marked with the new value yet. This short-circuiting is essential especially for high CPU count systems. The scheduler has a runqueue per cpu, and needs to take two runqueue locks at a time, which leads to long chains of backwards and forwards subgraphs from these runqueue lock nodes. Without the short-circuit implemented here, a graph traversal on a runqueue lock can take up to (1 << (N - 1)) checks on a system with N cpus. For anything more than 16 cpus or so, lockdep will eventually bring the machine to a complete standstill. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | generic-ipi: fix stack and rcu interaction bug in smp_call_function_mask()Nick Piggin2008-08-111-7/+47
| | |_|_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote: > Found a OOPS on a big SMP box during an overnight reboot test with > upstream git. > > Suresh and I looked at the oops and looks like the root cause is in > generic_smp_call_function_interrupt() and smp_call_function_mask() with > wait parameter. > > The actual oops looked like > > [ 11.277260] BUG: unable to handle kernel paging request at ffff8802ffffffff > [ 11.277815] IP: [<ffff8802ffffffff>] 0xffff8802ffffffff > [ 11.278155] PGD 202063 PUD 0 > [ 11.278576] Oops: 0010 [1] SMP > [ 11.279006] CPU 5 > [ 11.279336] Modules linked in: > [ 11.279752] Pid: 0, comm: swapper Not tainted 2.6.27-rc2-00020-g685d87f #290 > [ 11.280039] RIP: 0010:[<ffff8802ffffffff>] [<ffff8802ffffffff>] 0xffff8802ffffffff > [ 11.280692] RSP: 0018:ffff88027f1f7f70 EFLAGS: 00010086 > [ 11.280976] RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000000000000 > [ 11.281264] RDX: 0000000000004f4e RSI: 0000000000000001 RDI: 0000000000000000 > [ 11.281624] RBP: ffff88027f1f7f98 R08: 0000000000000001 R09: ffffffff802509af > [ 11.281925] R10: ffff8800280c2780 R11: 0000000000000000 R12: ffff88027f097d48 > [ 11.282214] R13: ffff88027f097d70 R14: 0000000000000005 R15: ffff88027e571000 > [ 11.282502] FS: 0000000000000000(0000) GS:ffff88027f1c3340(0000) knlGS:0000000000000000 > [ 11.283096] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > [ 11.283382] CR2: ffff8802ffffffff CR3: 0000000000201000 CR4: 00000000000006e0 > [ 11.283760] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 11.284048] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > [ 11.284337] Process swapper (pid: 0, threadinfo ffff88027f1f2000, task ffff88027f1f0640) > [ 11.284936] Stack: ffffffff80250963 0000000000000212 0000000000ee8c78 0000000000ee8a66 > [ 11.285802] ffff88027e571550 ffff88027f1f7fa8 ffffffff8021adb5 ffff88027f1f3e40 > [ 11.286599] ffffffff8020bdd6 ffff88027f1f3e40 <EOI> ffff88027f1f3ef8 0000000000000000 > [ 11.287120] Call Trace: > [ 11.287768] <IRQ> [<ffffffff80250963>] ? generic_smp_call_function_interrupt+0x61/0x12c > [ 11.288354] [<ffffffff8021adb5>] smp_call_function_interrupt+0x17/0x27 > [ 11.288744] [<ffffffff8020bdd6>] call_function_interrupt+0x66/0x70 > [ 11.289030] <EOI> [<ffffffff8024ab3b>] ? clockevents_notify+0x19/0x73 > [ 11.289380] [<ffffffff803b9b75>] ? acpi_idle_enter_simple+0x18b/0x1fa > [ 11.289760] [<ffffffff803b9b6b>] ? acpi_idle_enter_simple+0x181/0x1fa > [ 11.290051] [<ffffffff8053aeca>] ? cpuidle_idle_call+0x70/0xa2 > [ 11.290338] [<ffffffff80209f61>] ? cpu_idle+0x5f/0x7d > [ 11.290723] [<ffffffff8060224a>] ? start_secondary+0x14d/0x152 > [ 11.291010] > [ 11.291287] > [ 11.291654] Code: Bad RIP value. > [ 11.292041] RIP [<ffff8802ffffffff>] 0xffff8802ffffffff > [ 11.292380] RSP <ffff88027f1f7f70> > [ 11.292741] CR2: ffff8802ffffffff > [ 11.310951] ---[ end trace 137c54d525305f1c ]--- > > The problem is with the following sequence of events: > > - CPU A calls smp_call_function_mask() for CPU B with wait parameter > - CPU A sets up the call_function_data on the stack and does an rcu add to > call_function_queue > - CPU A waits until the WAIT flag is cleared > - CPU B gets the call function interrupt and starts going through the > call_function_queue > - CPU C also gets some other call function interrupt and starts going through > the call_function_queue > - CPU C, which is also going through the call_function_queue, starts referencing > CPU A's stack, as that element is still in call_function_queue > - CPU B finishes the function call that CPU A set up and as there are no other > references to it, rcu deletes the call_function_data (which was from CPU A > stack) > - CPU B sees the wait flag and just clears the flag (no call_rcu to free) > - CPU A which was waiting on the flag continues executing and the stack > contents change > > - CPU C is still in rcu_read section accessing the CPU A's stack sees > inconsistent call_funation_data and can try to execute > function with some random pointer, causing stack corruption for A > (by clearing the bits in mask field) and oops. Nice debugging work. I'd suggest something like the attached (boot tested) patch as the simple fix for now. I expect the benefits from the less synchronized, multiple-in-flight-data global queue will still outweigh the costs of dynamic allocations. But if worst comes to worst then we just go back to a globally synchronous one-at-a-time implementation, but that would be pretty sad! Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | DMA: make dma-coherent.c documentation kdoc-friendlyDmitry Baryshkov2008-08-071-5/+5
|/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Spotted by Randy. Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
* | | | | pm_qos: spelling fixesRichard Hughes2008-08-051-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A documentation cleanup patch. With a minor tweak to clarify units for kbs. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: mark gross <mgross@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | dma: fix order calculation in dma_mark_declared_memory_occupied()Jan Beulich2008-08-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_order() takes byte-sized input, not a page-granular one. Irrespective of this fix I'm inclined to believe that this doesn't work right anyway - bitmap_allocate_region() has an implicit assumption of 'pos' being suitable for 'order', which this function doesn't seem to enforce (and since it's being called with a byte-granular value there's no reason to believe that the callers would make sure device_addr is passed accordingly - it's also not documented that way). Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dmitry Baryshkov <dbaryshkov@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | genirq: better warning on irqchip->set_type() failureDavid Brownell2008-08-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While I'm glad to finally see the hole fixed whereby passing an invalid IRQ trigger type to request_irq() would be ignored, the current diagnostic isn't quite useful. Fixed by also listing the trigger type which was rejected. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | semaphore: __down_common: use signal_pending_state()Oleg Nesterov2008-08-051-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change __down_common() to use signal_pending_state() instead of open coding. The changes in kernel/semaphore.o are just artifacts, the state checks are optimized away. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | relay: fix "full buffer with exactly full last subbuffer" accounting problemTom Zanussi2008-08-051-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In relay's current read implementation, if the buffer is completely full but hasn't triggered the buffer-full condition (i.e. the last write didn't cross the subbuffer boundary) and the last subbuffer is exactly full, the subbuffer accounting code erroneously finds nothing available. This patch fixes the problem. Signed-off-by: Tom Zanussi <tzanussi@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Andrea Righi <righi.andrea@gmail.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge branch 'audit.b56' of ↵Linus Torvalds2008-08-041-0/+7
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b56' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is set
| * | | | | Re: [PATCH] Fix the kernel panic of audit_filter_task when key field is setzhangxiliang2008-08-041-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sorry, I miss a blank between if and "(". And I add "unlikely" to check "ctx" in audit_match_perm() and audit_match_filetype(). This is a new patch for it. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | | | __sched_setscheduler: don't do any policy checks when not "user"Jeremy Fitzhardinge2008-08-041-10/+12
|/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "user" parameter to __sched_setscheduler indicates whether the change is being done on behalf of a user process or not. If not, we shouldn't apply any permissions checks, so don't call security_task_setscheduler(). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Tested-by: Steve Wise <swise@opengridcomputing.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | tracehook: fix exit_signal=0 caseRoland McGrath2008-08-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My commit 2b2a1ff64afbadac842bbc58c5166962cf4f7664 introduced a regression (sorry about that) for the odd case of exit_signal=0 (e.g. clone_flags=0). This is not a normal use, but it's used by a case in the glibc test suite. Dying with exit_signal=0 sends no signal, but it's supposed to wake up a parent's blocked wait*() calls (unlike the delayed_group_leader case). This fixes tracehook_notify_death() and its caller to distinguish a "signal 0" wakeup from the delayed_group_leader case (with no wakeup). Signed-off-by: Roland McGrath <roland@redhat.com> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2008-08-011-0/+1
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: locking: fix mutex @key parameter kernel-doc notation
| * | | | | locking: fix mutex @key parameter kernel-doc notationRandy Dunlap2008-07-281-0/+1
| | |_|_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix @key parameter to mutex_init() and one of its callers. Warning(linux-2.6.26-git11//drivers/base/class.c:210): No description found for parameter 'key' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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