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2007-11-12sigwait eats blocked default-ignore signalsRoland McGrath1-1/+1
While a signal is blocked, it must be posted even if its action is SIG_IGN or is SIG_DFL with the default action to ignore. This works right most of the time, but is broken when a sigwait (rt_sigtimedwait) is in progress. This changes the early-discard check to respect real_blocked. ~blocked is the set to check for "should wake up now", but ~(blocked|real_blocked) is the set for "blocked" semantics as defined by POSIX. This fixes bugzilla entry 9347, see http://bugzilla.kernel.org/show_bug.cgi?id=9347 Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-09[FUTEX] Fix address computation in compat code.David Miller1-7/+19
compat_exit_robust_list() computes a pointer to the futex entry in userspace as follows: (void __user *)entry + futex_offset 'entry' is a 'struct robust_list __user *', and 'futex_offset' is a 'compat_long_t' (typically a 's32'). Things explode if the 32-bit sign bit is set in futex_offset. Type promotion sign extends futex_offset to a 64-bit value before adding it to 'entry'. This triggered a problem on sparc64 running 32-bit applications which would lock up a cpu looping forever in the fault handling for the userspace load in handle_futex_death(). Compat userspace runs with address masking (wherein the cpu zeros out the top 32-bits of every effective address given to a memory operation instruction) so the sparc64 fault handler accounts for this by zero'ing out the top 32-bits of the fault address too. Since the kernel properly uses the compat_uptr interfaces, kernel side accesses to compat userspace work too since they will only use addresses with the top 32-bit clear. Because of this compat futex layer bug we get into the following loop when executing the get_user() load near the top of handle_futex_death(): 1) load from address '0xfffffffff7f16bd8', FAULT 2) fault handler clears upper 32-bits, processes fault for address '0xf7f16bd8' which succeeds 3) goto #1 I want to thank Bernd Zeimetz, Josip Rodin, and Fabio Massimo Di Nitto for their tireless efforts helping me track down this bug. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-09sched: proper prototype for kernel/sched.c:migration_init()Adrian Bunk1-3/+1
This patch adds a proper prototype for migration_init() in include/linux/sched.h Since there's no point in always returning 0 to a caller that doesn't check the return value it also changes the function to return void. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: avoid large irq-latencies in smp-balancingPeter Zijlstra2-5/+18
SMP balancing is done with IRQs disabled and can iterate the full rq. When rqs are large this can cause large irq-latencies. Limit the nr of iterations on each run. This fixes a scheduling latency regression reported by the -rt folks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Gregory Haskins <ghaskins@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: fix copy_namespace() <-> sched_fork() dependency in do_forkSrivatsa Vaddagiri2-4/+5
Sukadev Bhattiprolu reported a kernel crash with control groups. There are couple of problems discovered by Suka's test: - The test requires the cgroup filesystem to be mounted with atleast the cpu and ns options (i.e both namespace and cpu controllers are active in the same hierarchy). # mkdir /dev/cpuctl # mount -t cgroup -ocpu,ns none cpuctl (or simply) # mount -t cgroup none cpuctl -> Will activate all controllers in same hierarchy. - The test invokes clone() with CLONE_NEWNS set. This causes a a new child to be created, also a new group (do_fork->copy_namespaces->ns_cgroup_clone-> cgroup_clone) and the child is attached to the new group (cgroup_clone-> attach_task->sched_move_task). At this point in time, the child's scheduler related fields are uninitialized (including its on_rq field, which it has inherited from parent). As a result sched_move_task thinks its on runqueue, when it isn't. As a solution to this problem, I moved sched_fork() call, which initializes scheduler related fields on a new task, before copy_namespaces(). I am not sure though whether moving up will cause other side-effects. Do you see any issue? - The second problem exposed by this test is that task_new_fair() assumes that parent and child will be part of the same group (which needn't be as this test shows). As a result, cfs_rq->curr can be NULL for the child. The solution is to test for curr pointer being NULL in task_new_fair(). With the patch below, I could run ns_exec() fine w/o a crash. Reported-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: clean up the wakeup preempt check, #2Ingo Molnar1-3/+2
clean up the preemption check to not use unnecessary 64-bit variables. This improves code size: text data bss dec hex filename 44227 3326 36 47589 b9e5 sched.o.before 44201 3326 36 47563 b9cb sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: clean up the wakeup preempt checkIngo Molnar1-12/+13
clean up the wakeup preemption check. No code changed: text data bss dec hex filename 44227 3326 36 47589 b9e5 sched.o.before 44227 3326 36 47589 b9e5 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: wakeup preemption fixIngo Molnar1-4/+2
wakeup preemption fix: do not make it dependent on p->prio. Preemption purely depends on ->vruntime. This improves preemption in mixed-nice-level workloads. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: remove PREEMPT_RESTRICTIngo Molnar2-11/+3
remove PREEMPT_RESTRICT. (this is a separate commit so that any regression related to the removal itself is bisectable) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: turn off PREEMPT_RESTRICTIngo Molnar1-1/+1
PREEMPT_RESTRICT was a method aimed at reducing the amount of wakeup related preemption. It has a disadvantage though, it can prevent legitimate wakeups if a task is 'unlucky' to be hit too early by a tick that clears peer_preempt. Now that the wakeup preemption has been cleaned up we dont seem to have excessive preemptions anymore, so this feature can be turned off. (and removed in the next patch) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: cleanup, use NSEC_PER_MSEC and NSEC_PER_SECEric Dumazet2-6/+6
1) hardcoded 1000000000 value is used five times in places where NSEC_PER_SEC might be more readable. 2) A conversion from nsec to msec uses the hardcoded 1000000 value, which is a candidate for NSEC_PER_MSEC. no code changed: text data bss dec hex filename 44359 3326 36 47721 ba69 sched.o.before 44359 3326 36 47721 ba69 sched.o.after Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: reintroduce SMP tunings againIngo Molnar2-9/+37
Yanmin Zhang reported an aim7 regression and bisected it down to: | commit 38ad464d410dadceda1563f36bdb0be7fe4c8938 | Author: Ingo Molnar <mingo@elte.hu> | Date: Mon Oct 15 17:00:02 2007 +0200 | | sched: uniform tunings | | use the same defaults on both UP and SMP. fix this by reintroducing similar SMP tunings again. This resolves the regression. (also update the comments to match the ilog2(nr_cpus) tuning effect) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: restore deterministic CPU accounting on powerpcPaul Mackerras1-7/+14
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been broken on powerpc, because we end up counting user time twice: once in timer_interrupt() and once in update_process_times(). This fixes the problem by pulling the code in update_process_times that updates utime and stime into a separate function called account_process_tick. If CONFIG_VIRT_CPU_ACCOUNTING is not defined, there is a version of account_process_tick in kernel/timer.c that simply accounts a whole tick to either utime or stime as before. If CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to implement account_process_tick. This also lets us simplify the s390 code a bit; it means that the s390 timer interrupt can now call update_process_times even when CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a suitable account_process_tick(). account_process_tick() now takes the task_struct * as an argument. Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: fix delay accounting regressionBalbir Singh1-5/+6
Fix the delay accounting regression introduced by commit 75d4ef16a6aa84f708188bada182315f80aab6fa. rq no longer has sched_info data associated with it. task_struct sched_info structure is used by delay accounting to provide back statistics to user space. also remove direct use of sched_clock() (which is not a valid thing to do anymore) and use rq->clock instead. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: reintroduce the sched_min_granularity tunablePeter Zijlstra3-12/+36
we lost the sched_min_granularity tunable to a clever optimization that uses the sched_latency/min_granularity ratio - but the ratio is quite unintuitive to users and can also crash the kernel if the ratio is set to 0. So reintroduce the min_granularity tunable, while keeping the ratio maintained internally. no functionality changed. [ mingo@elte.hu: some fixlets. ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: documentation: place_entity() commentsPeter Zijlstra1-2/+9
Add a few comments to place_entity(). No code changed. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: fix vslicePeter Zijlstra1-0/+1
vslice was missing a factor NICE_0_LOAD, as weight is in weight*NICE_0_LOAD units. the effect of this bug was larger initial slices and thus latency-noisier forks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-05time: fix inconsistent function names in commentsLi Zefan3-3/+3
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-05Dump stack during sysctl registration failureAlexey Dobriyan1-0/+1
Let's make immediately obvious from where sysctl comes from and messages itself more noticeable. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-05kernel/futex.c: make 3 functions staticAdrian Bunk1-7/+4
The following functions can now become static again: - get_futex_key() - get_futex_key_refs() - drop_futex_key_refs() Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-11-03Merge branch 'v2.6.24-rc1-lockdep' of ↵Linus Torvalds2-3/+4
git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep * 'v2.6.24-rc1-lockdep' of git://git.kernel.org/pub/scm/linux/kernel/git/peterz/linux-2.6-lockdep: lockdep: fix a typo in the __lock_acquire comment sched: fix unconditional irq lock lockdep: fixup irq tracing
2007-10-30[COMPAT]: Fix build on COMPAT platforms when CONFIG_NET is disabled.David S. Miller1-0/+4
Add some missing cond_syscall() entries for this case. Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-30Freezer: do not allow freezing processes to clear TIF_SIGPENDINGRafael J. Wysocki1-1/+1
Do not allow processes to clear their TIF_SIGPENDING if TIF_FREEZE is set, so that they will not race with the freezer (like mysqld does, for example). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@suspend2.net> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-30sched: fix /proc/<PID>/stat stime/utime monotonicity, part 2Balbir Singh1-0/+1
Extend Peter's patch to fix accounting issues, by keeping stime monotonic too. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Frans Pop <elendil@planet.nl>
2007-10-29sched: fix style in kernel/sched.cIngo Molnar1-9/+9
fallout of recent commits: small coding style fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: fix style of swap() macro in kernel/sched_fair.cIngo Molnar1-1/+1
fix style of swap() macro in kernel/sched_fair.c. ( this macro should eventually move to a general header, as ext3 uses a similar construct too. ) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: report CPU usage in CFS cgroup directoriesPaul Menage1-5/+33
Adds a cpu.usage file to the CFS cgroup that reports CPU usage in milliseconds for that cgroup's tasks [ mingo@elte.hu: style cleanups. ] Signed-off-by: Paul Menage <menage@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: move rcu_head to task_group structSrivatsa Vaddagiri1-4/+4
Peter Zijlstra noticed that the rcu_head object need not be present in every cfs_rq of a group. Move it to the task_group structure instead. Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: fix incorrect assumption that cpu 0 existsJames Bottomley1-2/+2
This patch: commit 9b5b77512dce239fa168183fa71896712232e95a Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Date: Mon Oct 15 17:00:09 2007 +0200 sched: clean up code under CONFIG_FAIR_GROUP_SCHED Introduced an assumption of the existence of CPU0 via this line cfs_rq = tg->cfs_rq[0]; If you have no CPU0, that will be NULL. The fix seems to be just to take whatever cfs_rq queue comes out of the for_each_possible_cpu() loop, since they're all equally good for the destruction operation. Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: keep utime/stime monotonicPeter Zijlstra1-0/+1
keep utime/stime monotonic. cpustats use utime/stime as a ratio against sum_exec_runtime, as a consequence it can happen - when the ratio changes faster than time accumulates - that either can be appear to go backwards. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29sched: make kernel/sched.c:account_guest_time() staticAdrian Bunk1-1/+1
account_guest_time() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrtLinus Torvalds3-5/+5
* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt: Quieten hrtimer printk: "Switched to high resolution mode .." timer_list: Fix printk format strings clockevents: unexport tick_nohz_get_sleep_length
2007-10-29x86 merge fallout: umlAl Viro1-1/+1
Don't undef __i386__/__x86_64__ in uml anymore, make sure that (few) places that required adjusting the ifdefs got those. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-29Quieten hrtimer printk: "Switched to high resolution mode .."Michael Ellerman1-1/+1
Change the hrtimer printk "Switched to high resolution mode .." to be KERN_DEBUG, rather than KERN_INFO. If users need to see this they can pass "loglevel" or "debug" on the command line, or check dmesg. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> kernel/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
2007-10-29timer_list: Fix printk format stringsVegard Nossum1-2/+4
This makes sure printk format strings contain no more than a single line. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-29clockevents: unexport tick_nohz_get_sleep_lengthAdrian Bunk1-2/+0
This patch removes the unused EXPORT_SYMBOL_GPL(tick_nohz_get_sleep_length). Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-28lockdep: fix a typo in the __lock_acquire commentGautham R Shenoy1-1/+1
Fix a typo in the __lock_acquire comment. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-25sched: fix unconditional irq lockPeter Zijlstra1-2/+3
Lockdep noticed that this lock can also be taken from hardirq context, and can thus not unconditionally disable/enable irqs. WARNING: at kernel/lockdep.c:2033 trace_hardirqs_on() [show_trace_log_lvl+26/48] show_trace_log_lvl+0x1a/0x30 [show_trace+18/32] show_trace+0x12/0x20 [dump_stack+22/32] dump_stack+0x16/0x20 [trace_hardirqs_on+405/416] trace_hardirqs_on+0x195/0x1a0 [_read_unlock_irq+34/48] _read_unlock_irq+0x22/0x30 [sched_debug_show+2615/4224] sched_debug_show+0xa37/0x1080 [show_state_filter+326/368] show_state_filter+0x146/0x170 [sysrq_handle_showstate+10/16] sysrq_handle_showstate+0xa/0x10 [__handle_sysrq+123/288] __handle_sysrq+0x7b/0x120 [handle_sysrq+40/64] handle_sysrq+0x28/0x40 [kbd_event+1045/1680] kbd_event+0x415/0x690 [input_pass_event+206/208] input_pass_event+0xce/0xd0 [input_handle_event+170/928] input_handle_event+0xaa/0x3a0 [input_event+95/112] input_event+0x5f/0x70 [atkbd_interrupt+434/1456] atkbd_interrupt+0x1b2/0x5b0 [serio_interrupt+59/128] serio_interrupt+0x3b/0x80 [i8042_interrupt+263/576] i8042_interrupt+0x107/0x240 [handle_IRQ_event+40/96] handle_IRQ_event+0x28/0x60 [handle_edge_irq+175/320] handle_edge_irq+0xaf/0x140 [do_IRQ+64/128] do_IRQ+0x40/0x80 [common_interrupt+46/52] common_interrupt+0x2e/0x34 Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: isolate SMP balancing code a bit morePeter Williams4-17/+12
At the moment, a lot of load balancing code that is irrelevant to non SMP systems gets included during non SMP builds. This patch addresses this issue and reduces the binary size on non SMP systems: text data bss dec hex filename 10983 28 1192 12203 2fab sched.o.before 10739 28 1192 11959 2eb7 sched.o.after Signed-off-by: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: reduce balance-tasks overheadPeter Williams4-55/+130
At the moment, balance_tasks() provides low level functionality for both move_tasks() and move_one_task() (indirectly) via the load_balance() function (in the sched_class interface) which also provides dual functionality. This dual functionality complicates the interfaces and internal mechanisms and makes the run time overhead of operations that are called with two run queue locks held. This patch addresses this issue and reduces the overhead of these operations. Signed-off-by: Peter Williams <pwil3058@bigpond.net.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: make cpu_shares_{show,store}() staticAdrian Bunk1-2/+3
cpu_shares_{show,store}() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: clean up some control group codePaul Menage1-35/+18
- replace "cont" with "cgrp" in a few places in the CFS cgroup code, - use write_uint rather than write for cpu.shares write function Signed-off-by: Paul Menage <menage@google.com> Acked-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: document profile=sleep requiring CONFIG_SCHEDSTATSMel Gorman1-0/+5
profile=sleep only works if CONFIG_SCHEDSTATS is set. This patch notes the limitation in Documentation/kernel-parameters.txt and prints a warning at boot-time if profile=sleep is used without CONFIG_SCHEDSTAT. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: use show_regs() to improve __schedule_bug() outputSatyam Sharma1-3/+11
A full register dump along with stack backtrace would make the "scheduling while atomic" message more helpful. Use show_regs() instead of dump_stack() for this. We already know we're atomic in here (that is why this function was called) so show_regs()'s atomicity expectations are guaranteed. Also, modify the output of the "BUG: scheduling while atomic:" header a bit to keep task->comm and task->pid together and preempt_count() after them. Signed-off-by: Satyam Sharma <satyam@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: clean up sched_domain_debug()Ingo Molnar1-73/+73
clean up sched_domain_debug(). this also shrinks the code a bit: text data bss dec hex filename 50474 4306 480 55260 d7dc sched.o.before 50404 4306 480 55190 d796 sched.o.after Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: fix fastcall mismatch in completion APIsIngo Molnar1-5/+5
Jeff Dike noticed that wait_for_completion_interruptible()'s prototype had a mismatched fastcall. Fix this by removing the fastcall attributes from all the completion APIs. Found-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24sched: fix sched_domain sysctl registration againMilton Miller1-5/+20
commit 029190c515f15f512ac85de8fc686d4dbd0ae731 (cpuset sched_load_balance flag) was not tested SCHED_DEBUG enabled as committed as it dereferences NULL when used and it reordered the sysctl registration to cause it to never show any domains or their tunables. Fixes: 1) restore arch_init_sched_domains ordering we can't walk the domains before we build them presently we register cpus with empty directories (no domain directories or files). 2) make unregister_sched_domain_sysctl do nothing when already unregistered detach_destroy_domains is now called one set of cpus at a time unregister_syctl dereferences NULL if called with a null. While the the function would always dereference null if called twice, in the previous code it was always called once and then was followed a register. So only the hidden bug of the sysctl_root_table not being allocated followed by an attempt to free it would have shown the error. 3) always call unregister and register in partition_sched_domains The code is "smart" about unregistering only needed domains. Since we aren't guaranteed any calls to unregister, always unregister. Without calling register on the way out we will not have a table or any sysctl tree. 4) warn if register is called without unregistering The previous table memory is lost, leaving pointers to the later freed memory in sysctl and leaking the memory of the tables. Before this patch on a 2-core 4-thread box compiled for SMT and NUMA, the domains appear empty (there are actually 3 levels per cpu). And as soon as two domains a null pointer is dereferenced (unreliable in this case is stack garbage): bu19a:~# ls -R /proc/sys/kernel/sched_domain/ /proc/sys/kernel/sched_domain/: cpu0 cpu1 cpu2 cpu3 /proc/sys/kernel/sched_domain/cpu0: /proc/sys/kernel/sched_domain/cpu1: /proc/sys/kernel/sched_domain/cpu2: /proc/sys/kernel/sched_domain/cpu3: bu19a:~# mkdir /dev/cpuset bu19a:~# mount -tcpuset cpuset /dev/cpuset/ bu19a:~# cd /dev/cpuset/ bu19a:/dev/cpuset# echo 0 > sched_load_balance bu19a:/dev/cpuset# mkdir one bu19a:/dev/cpuset# echo 1 > one/cpus bu19a:/dev/cpuset# echo 0 > one/sched_load_balance Unable to handle kernel paging request for data at address 0x00000018 Faulting instruction address: 0xc00000000006b608 NIP: c00000000006b608 LR: c00000000006b604 CTR: 0000000000000000 REGS: c000000018d973f0 TRAP: 0300 Not tainted (2.6.23-bml) MSR: 9000000000009032 <EE,ME,IR,DR> CR: 28242442 XER: 00000000 DAR: 0000000000000018, DSISR: 0000000040000000 TASK = c00000001912e340[1987] 'bash' THREAD: c000000018d94000 CPU: 2 .. NIP [c00000000006b608] .unregister_sysctl_table+0x38/0x110 LR [c00000000006b604] .unregister_sysctl_table+0x34/0x110 Call Trace: [c000000018d97670] [c000000007017270] 0xc000000007017270 (unreliable) [c000000018d97720] [c000000000058710] .detach_destroy_domains+0x30/0xb0 [c000000018d977b0] [c00000000005cf1c] .partition_sched_domains+0x1bc/0x230 [c000000018d97870] [c00000000009fdc4] .rebuild_sched_domains+0xb4/0x4c0 [c000000018d97970] [c0000000000a02e8] .update_flag+0x118/0x170 [c000000018d97a80] [c0000000000a1768] .cpuset_common_file_write+0x568/0x820 [c000000018d97c00] [c00000000009d95c] .cgroup_file_write+0x7c/0x180 [c000000018d97cf0] [c0000000000e76b8] .vfs_write+0xe8/0x1b0 [c000000018d97d90] [c0000000000e810c] .sys_write+0x4c/0x90 [c000000018d97e30] [c00000000000852c] syscall_exit+0x0/0x40 Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-23cgroup: kill unused variableJeff Garzik1-1/+0
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2007-10-23Fix synchronize_irq races with IRQ handlerHerbert Xu1-2/+18
As it is some callers of synchronize_irq rely on memory barriers to provide synchronisation against the IRQ handlers. For example, the tg3 driver does tp->irq_sync = 1; smp_mb(); synchronize_irq(); and then in the IRQ handler: if (!tp->irq_sync) netif_rx_schedule(dev, &tp->napi); Unfortunately memory barriers only work well when they come in pairs. Because we don't actually have memory barriers on the IRQ path, the memory barrier before the synchronize_irq() doesn't actually protect us. In particular, synchronize_irq() may return followed by the result of netif_rx_schedule being made visible. This patch (mostly written by Linus) fixes this by using spin locks instead of memory barries on the synchronize_irq() path. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22auditsc: fix kernel-doc param warningsRandy Dunlap1-2/+2
Fix kernel-doc for auditsc parameter changes. Warning(linux-2.6.23-git17//kernel/auditsc.c:1623): No description found for parameter 'dentry' Warning(linux-2.6.23-git17//kernel/auditsc.c:1666): No description found for parameter 'dentry' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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