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2009-02-13Merge branch 'linus' into x86/apicIngo Molnar
Conflicts: arch/x86/kernel/acpi/boot.c arch/x86/mm/fault.c
2009-02-13Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/acpi/boot.c
2009-02-12Merge branch 'linus' into core/softlockupIngo Molnar
2009-02-12Add in_execve flag into task_struct.Kentaro Takeda
This patch allows LSM modules to determine whether current process is in an execve operation or not so that they can behave differently while an execve operation is in progress. This patch is needed by TOMOYO. Please see another patch titled "LSM adapter functions." for backgrounds. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-11timers: fix TIMER_ABSTIME for process wide cpu timersPeter Zijlstra
The POSIX timer interface allows for absolute time expiry values through the TIMER_ABSTIME flag, therefore we have to synchronize the timer to the clock every time we start it. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11timers: split process wide cpu clocks/timers, fixPeter Zijlstra
To decrease the chance of a missed enable, always enable the timer when we sample it, we'll always disable it when we find that there are no active timers in the jiffy tick. This fixes a flood of warnings reported by Mike Galbraith. Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-11Merge commit 'v2.6.29-rc4' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/kernel/setup_percpu.c arch/x86/mm/fault.c drivers/acpi/processor_idle.c kernel/irq/handle.c
2009-02-09perf_counters: make software counters work as per-cpu countersPaul Mackerras
Impact: kernel crash fix Yanmin Zhang reported that using a PERF_COUNT_TASK_CLOCK software counter as a per-cpu counter would reliably crash the system, because it calls __task_delta_exec with a null pointer. The page fault, context switch and cpu migration counters also won't function correctly as per-cpu counters since they reference the current task. This fixes the problem by redirecting the task_clock counter to the cpu_clock counter when used as a per-cpu counter, and by implementing per-cpu page fault, context switch and cpu migration counters. Along the way, this: - Initializes counter->ctx earlier, in perf_counter_alloc, so that sw_perf_counter_init can use it - Adds code to kernel/sched.c to count task migrations into each cpu, in rq->nr_migrations_in - Exports the per-cpu context switch and task migration counts via new functions added to kernel/sched.c - Makes sure that if sw_perf_counter_init fails, we don't try to initialize the counter as a hardware counter. Since the user has passed a negative, non-raw event type, they clearly don't intend for it to be interpreted as a hardware event. Reported-by: "Zhang Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09softlockup: remove timestamp checking from hung_taskMandeep Singh Baines
Impact: saves sizeof(long) bytes per task_struct By guaranteeing that sysctl_hung_task_timeout_secs have elapsed between tasklist scans we can avoid using timestamps. Signed-off-by: Mandeep Singh Baines <msb@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09Merge commit 'v2.6.29-rc4' into tracing/coreIngo Molnar
2009-02-08Merge branches 'sched/rt' and 'sched/urgent' into sched/coreIngo Molnar
2009-02-07Merge branch 'linus' into core/lockingIngo Molnar
Conflicts: fs/btrfs/locking.c
2009-02-06timers: split process wide cpu clocks/timers, remove spurious warningIngo Molnar
Mike Galbraith reported that the new warning in thread_group_cputimer() triggers en masse with Amarok running. Oleg Nesterov observed: Can't fastpath_timer_check()->thread_group_cputimer() have the false warning too? Suppose we had the timer, then posix_cpu_timer_del() removes this timer, but task_cputime_zero(&sig->cputime_expires) still not true. Remove the spurious debug warning. Reported-by: Mike Galbraith <efault@gmx.de> Explained-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05Merge branch 'x86/urgent' into x86/apicIngo Molnar
Conflicts: arch/x86/mach-default/setup.c Semantic merge: arch/x86/kernel/irqinit_32.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05timers: split process wide cpu clocks/timersPeter Zijlstra
Change the process wide cpu timers/clocks so that we: 1) don't mess up the kernel with too many threads, 2) don't have a per-cpu allocation for each process, 3) have no impact when not used. In order to accomplish this we're going to split it into two parts: - clocks; which can take all the time they want since they run from user context -- ie. sys_clock_gettime(CLOCK_PROCESS_CPUTIME_ID) - timers; which need constant time sampling but since they're explicity used, the user can pay the overhead. The clock readout will go back to a full sum of the thread group, while the timers will run of a global 'clock' that only runs when needed, so only programs that make use of the facility pay the price. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-05signal: re-add dead task accumulation stats.Peter Zijlstra
We're going to split the process wide cpu accounting into two parts: - clocks; which can take all the time they want since they run from user context. - timers; which need constant time tracing but can affort the overhead because they're default off -- and rare. The clock readout will go back to a full sum of the thread group, for this we need to re-add the exit stats that were removed in the initial itimer rework (f06febc9: timers: fix itimer/many thread hang). Furthermore, since that full sum can be rather slow for large thread groups and we have the complete dead task stats, revert the do_notify_parent time computation. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03sched: add missing kernel-doc in sched.hRandy Dunlap
Add kernel-doc notation for @lock: include/linux/sched.h:457: No description found for parameter 'lock' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-03Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into ↵Ingo Molnar
tracing/core
2009-01-31softlockup: remove unused definition for spawn_softlockup_taskMandeep Singh Baines
The definition of spawn_softlockup_task in sched.h became unnecessary once it was converted to the early_initcall() interface. Signed-off-by: Mandeep Singh Baines <msb@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-29epoll: drop max_user_instances and rely only on max_user_watchesDavide Libenzi
Linus suggested to put limits where the money is, and max_user_watches already does that w/out the need of max_user_instances. That has the advantage to mitigate the potential DoS while allowing pretty generous default behavior. Allowing top 4% of low memory (per user) to be allocated in epoll watches, we have: LOMEM MAX_WATCHES (per user) 512MB ~178000 1GB ~356000 2GB ~712000 A box with 512MB of lomem, will meet some challenge in hitting 180K watches, socket buffers math teaches us. No more max_user_instances limits then. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Willy Tarreau <w@1wt.eu> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Bron Gondwana <brong@fastmail.fm> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-27Merge branch 'linus' into core/percpuIngo Molnar
Conflicts: arch/x86/kernel/setup_percpu.c
2009-01-26Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
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: debugobjects: add and use INIT_WORK_ON_STACK rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR relay: fix lock imbalance in relay_late_setup_files oprofile: fix uninitialized use of struct op_entry rcu: move Kconfig menu softlock: fix false panic which can occur if softlockup_thresh is reduced rcu: add __cpuinit to rcu_init_percpu_data()
2009-01-23trace, lockdep: manual preempt count adding for local_bh_disableSteven Rostedt
Impact: fix to preempt trace triggering lockdep check_flag failure In local_bh_disable, the use of add_preempt_count causes the preempt tracer to start recording the time preemption is off. But because it already modified the preempt_count to show softirqs disabled, and before it called the lockdep code to handle this, it causes a state that lockdep can not handle. The preempt tracer will reset the ring buffer on start of a trace, and the ring buffer reset code does a spin_lock_irqsave. This calls into lockdep and lockdep will fail when it detects the invalid state of having softirqs disabled but the internal current->softirqs_enabled is still set. The fix is to manually add the SOFTIRQ_OFFSET to preempt count and call the preempt tracer code outside the lockdep critical area. Thanks to Peter Zijlstra for suggesting this solution. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23Merge branch 'core/percpu' into perfcounters/coreIngo Molnar
Conflicts: arch/x86/include/asm/hardirq_32.h arch/x86/include/asm/hardirq_64.h Semantic merge: arch/x86/include/asm/hardirq.h [ added apic_perf_irqs field. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18Merge branch 'core/percpu' into stackprotectorIngo Molnar
Conflicts: arch/x86/include/asm/pda.h arch/x86/include/asm/system.h Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16softlockup: decouple hung tasks check from softlockup detectionMandeep Singh Baines
Decoupling allows: * hung tasks check to happen at very low priority * hung tasks check and softlockup to be enabled/disabled independently at compile and/or run-time * individual panic settings to be enabled disabled independently at compile and/or run-time * softlockup threshold to be reduced without increasing hung tasks poll frequency (hung task check is expensive relative to softlock watchdog) * hung task check to be zero over-head when disabled at run-time Signed-off-by: Mandeep Singh Baines <msb@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16sched: fix !CONFIG_SCHEDSTATS build failureIngo Molnar
Stephen Rothwell reported this linux-next build failure with !CONFIG_SCHEDSTATS: | In file included from kernel/sched.c:1703: | kernel/sched_fair.c: In function 'adaptive_gran': | kernel/sched_fair.c:1324: error: 'struct sched_entity' has no member named 'avg_wakeup' The start_runtime and avg_wakeup metrics are now not just for statistics, but also for scheduling - so they always need to be available. (Also move out the nr_migrations fields - for future perfcounters usage.) Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-15sched: introduce avg_wakeupPeter Zijlstra
Introduce a new avg_wakeup statistic. avg_wakeup is a measure of how frequently a task wakes up other tasks, it represents the average time between wakeups, with a limit of avg_runtime for when it doesn't wake up anybody. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14mutex: implement adaptive spinningPeter Zijlstra
Change mutex contention behaviour such that it will sometimes busy wait on acquisition - moving its behaviour closer to that of spinlocks. This concept got ported to mainline from the -rt tree, where it was originally implemented for rtmutexes by Steven Rostedt, based on work by Gregory Haskins. Testing with Ingo's test-mutex application (http://lkml.org/lkml/2006/1/8/50) gave a 345% boost for VFS scalability on my testbox: # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 296604 # ./test-mutex-shm V 16 10 | grep "^avg ops" avg ops/sec: 85870 The key criteria for the busy wait is that the lock owner has to be running on a (different) cpu. The idea is that as long as the owner is running, there is a fair chance it'll release the lock soon, and thus we'll be better off spinning instead of blocking/scheduling. Since regular mutexes (as opposed to rtmutexes) do not atomically track the owner, we add the owner in a non-atomic fashion and deal with the races in the slowpath. Furthermore, to ease the testing of the performance impact of this new code, there is means to disable this behaviour runtime (without having to reboot the system), when scheduler debugging is enabled (CONFIG_SCHED_DEBUG=y), by issuing the following command: # echo NO_OWNER_SPIN > /debug/sched_features This command re-enables spinning again (this is also the default): # echo OWNER_SPIN > /debug/sched_features Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14mutex: preemption fixesPeter Zijlstra
The problem is that dropping the spinlock right before schedule is a voluntary preemption point and can cause a schedule, right after which we schedule again. Fix this inefficiency by keeping preemption disabled until we schedule, do this by explicity disabling preemption and providing a schedule() variant that assumes preemption is already disabled. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14softlock: fix false panic which can occur if softlockup_thresh is reducedMandeep Singh Baines
At run-time, if softlockup_thresh is changed to a much lower value, touch_timestamp is likely to be much older than the new softlock_thresh. This will cause a false softlockup to be detected. If softlockup_panic is enabled, the system will panic. The fix is to touch all watchdogs before changing softlockup_thresh. Signed-off-by: Mandeep Singh Baines <msb@google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-11Merge branch 'sched/latest' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/ghaskins/linux-2.6-hacks into sched/rt
2009-01-11Merge commit 'v2.6.29-rc1' into perfcounters/coreIngo Molnar
Conflicts: include/linux/kernel_stat.h
2009-01-07itimers: remove the per-cpu-ish-nessPeter Zijlstra
Either we bounce once cacheline per cpu per tick, yielding n^2 bounces or we just bounce a single.. Also, using per-cpu allocations for the thread-groups complicates the per-cpu allocator in that its currently aimed to be a fixed sized allocator and the only possible extention to that would be vmap based, which is seriously constrained on 32 bit archs. So making the per-cpu memory requirement depend on the number of processes is an issue. Lastly, it didn't deal with cpu-hotplug, although admittedly that might be fixable. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-06Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
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: fix section mismatch sched: fix double kfree in failure path sched: clean up arch_reinit_sched_domains() sched: mark sched_create_sysfs_power_savings_entries() as __init getrusage: RUSAGE_THREAD should return ru_utime and ru_stime sched: fix sched_slice() sched_clock: prevent scd->clock from moving backwards, take #2 sched: sched.c declare variables before they get used
2009-01-06mm: introduce get_mm_hiwater_xxx(), fix taskstats->hiwater_xxx accountingOleg Nesterov
xacct_add_tsk() relies on do_exit()->update_hiwater_xxx() and uses mm->hiwater_xxx directly, this leads to 2 problems: - taskstats_user_cmd() can call fill_pid()->xacct_add_tsk() at any moment before the task exits, so we should check the current values of rss/vm anyway. - do_exit()->update_hiwater_xxx() calls are racy. An exiting thread can be preempted right before mm->hiwater_xxx = new_val, and another thread can use A_LOT of memory and exit in between. When the first thread resumes it can be the last thread in the thread group, in that case we report the wrong hiwater_xxx values which do not take A_LOT into account. Introduce get_mm_hiwater_rss() and get_mm_hiwater_vm() helpers and change xacct_add_tsk() to use them. The first helper will also be used by rusage->ru_maxrss accounting. Kill do_exit()->update_hiwater_xxx() calls. Unless we are going to decrease rss/vm there is no point to update mm->hiwater_xxx, and nobody can look at this mm_struct when exit_mmap() actually unmaps the memory. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Hugh Dickins <hugh@veritas.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06Merge branches 'sched/clock', 'sched/cleanups' and 'linus' into sched/urgentIngo Molnar
2009-01-05sched: clean up arch_reinit_sched_domains()Li Zefan
- Make arch_reinit_sched_domains() static. It was exported to be used in s390, but now rebuild_sched_domains() is used instead. - Make it return void. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-03Merge branch 'cputime' of git://git390.osdl.marist.edu/pub/scm/linux-2.6Linus Torvalds
* 'cputime' of git://git390.osdl.marist.edu/pub/scm/linux-2.6: [PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID [PATCH] improve idle cputime accounting [PATCH] improve precision of idle time detection. [PATCH] improve precision of process accounting. [PATCH] idle cputime accounting [PATCH] fix scaled & unscaled cputime accounting
2009-01-02Merge branch 'cpus4096-for-linus-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (66 commits) x86: export vector_used_by_percpu_irq x86: use logical apicid in x2apic_cluster's x2apic_cpu_mask_to_apicid_and() sched: nominate preferred wakeup cpu, fix x86: fix lguest used_vectors breakage, -v2 x86: fix warning in arch/x86/kernel/io_apic.c sched: fix warning in kernel/sched.c sched: move test_sd_parent() to an SMP section of sched.h sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0 sched: activate active load balancing in new idle cpus sched: bias task wakeups to preferred semi-idle packages sched: nominate preferred wakeup cpu sched: favour lower logical cpu number for sched_mc balance sched: framework for sched_mc/smt_power_savings=N sched: convert BALANCE_FOR_xx_POWER to inline functions x86: use possible_cpus=NUM to extend the possible cpus allowed x86: fix cpu_mask_to_apicid_and to include cpu_online_mask x86: update io_apic.c to the new cpumask code x86: Introduce topology_core_cpumask()/topology_thread_cpumask() x86: xen: use smp_call_function_many() x86: use work_on_cpu in x86/kernel/cpu/mcheck/mce_amd_64.c ... Fixed up trivial conflict in kernel/time/tick-sched.c manually
2008-12-31[PATCH] idle cputime accountingMartin Schwidefsky
The cpu time spent by the idle process actually doing something is currently accounted as idle time. This is plain wrong, the architectures that support VIRT_CPU_ACCOUNTING=y can do better: distinguish between the time spent doing nothing and the time spent by idle doing work. The first is accounted with account_idle_time and the second with account_system_time. The architectures that use the account_xxx_time interface directly and not the account_xxx_ticks interface now need to do the check for the idle process in their arch code. In particular to improve the system vs true idle time accounting the arch code needs to measure the true idle time instead of just testing for the idle process. To improve the tick based accounting as well we would need an architecture primitive that can tell us if the pt_regs of the interrupted context points to the magic instruction that halts the cpu. In addition idle time is no more added to the stime of the idle process. This field now contains the system time of the idle process as it should be. On systems without VIRT_CPU_ACCOUNTING this will always be zero as every tick that occurs while idle is running will be accounted as idle time. This patch contains the necessary common code changes to be able to distinguish idle system time and true idle time. The architectures with support for VIRT_CPU_ACCOUNTING need some changes to exploit this. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31Merge branch 'linus' into stackprotectorIngo Molnar
Conflicts: arch/x86/include/asm/pda.h kernel/fork.c
2008-12-30sched: sched.c declare variables before they get usedJaswinder Singh Rajput
Impact: cleanup, avoid sparse warnings In linux/sched.h moved out sysctl_sched_latency, sysctl_sched_min_granularity, sysctl_sched_wakeup_granularity, sysctl_sched_shares_ratelimit and sysctl_sched_shares_thresh from #ifdef CONFIG_SCHED_DEBUG as these variables are common for both. Fixes these sparse warnings: kernel/sched.c:825:14: warning: symbol 'sysctl_sched_shares_ratelimit' was not declared. Should it be static? kernel/sched.c:832:14: warning: symbol 'sysctl_sched_shares_thresh' was not declared. Should it be static? kernel/sched_fair.c:37:14: warning: symbol 'sysctl_sched_latency' was not declared. Should it be static? kernel/sched_fair.c:43:14: warning: symbol 'sysctl_sched_min_granularity' was not declared. Should it be static? kernel/sched_fair.c:72:14: warning: symbol 'sysctl_sched_wakeup_granularity' was not declared. Should it be static? Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29sched: create "pushable_tasks" list to limit pushing to one attemptGregory Haskins
The RT scheduler employs a "push/pull" design to actively balance tasks within the system (on a per disjoint cpuset basis). When a task is awoken, it is immediately determined if there are any lower priority cpus which should be preempted. This is opposed to the way normal SCHED_OTHER tasks behave, which will wait for a periodic rebalancing operation to occur before spreading out load. When a particular RQ has more than 1 active RT task, it is said to be in an "overloaded" state. Once this occurs, the system enters the active balancing mode, where it will try to push the task away, or persuade a different cpu to pull it over. The system will stay in this state until the system falls back below the <= 1 queued RT task per RQ. However, the current implementation suffers from a limitation in the push logic. Once overloaded, all tasks (other than current) on the RQ are analyzed on every push operation, even if it was previously unpushable (due to affinity, etc). Whats more, the operation stops at the first task that is unpushable and will not look at items lower in the queue. This causes two problems: 1) We can have the same tasks analyzed over and over again during each push, which extends out the fast path in the scheduler for no gain. Consider a RQ that has dozens of tasks that are bound to a core. Each one of those tasks will be encountered and skipped for each push operation while they are queued. 2) There may be lower-priority tasks under the unpushable task that could have been successfully pushed, but will never be considered until either the unpushable task is cleared, or a pull operation succeeds. The net result is a potential latency source for mid priority tasks. This patch aims to rectify these two conditions by introducing a new priority sorted list: "pushable_tasks". A task is added to the list each time a task is activated or preempted. It is removed from the list any time it is deactivated, made current, or fails to push. This works because a task only needs to be attempted to push once. After an initial failure to push, the other cpus will eventually try to pull the task when the conditions are proper. This also solves the problem that we don't completely analyze all tasks due to encountering an unpushable tasks. Now every task will have a push attempted (when appropriate). This reduces latency both by shorting the critical section of the rq->lock for certain workloads, and by making sure the algorithm considers all eligible tasks in the system. [ rostedt: added a couple more BUG_ONs ] Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Steven Rostedt <srostedt@redhat.com>
2008-12-29sched: add sched_class->needs_post_schedule() memberGregory Haskins
We currently run class->post_schedule() outside of the rq->lock, which means that we need to test for the need to post_schedule outside of the lock to avoid a forced reacquistion. This is currently not a problem as we only look at rq->rt.overloaded. However, we want to enhance this going forward to look at more state to reduce the need to post_schedule to a bare minimum set. Therefore, we introduce a new member-func called needs_post_schedule() which tests for the post_schedule condtion without actually performing the work. Therefore it is safe to call this function before the rq->lock is released, because we are guaranteed not to drop the lock at an intermediate point (such as what post_schedule() may do). We will use this later in the series [ rostedt: removed paranoid BUG_ON ] Signed-off-by: Gregory Haskins <ghaskins@novell.com>
2008-12-29Merge branch 'linus' into perfcounters/coreIngo Molnar
Conflicts: fs/exec.c include/linux/init_task.h Simple context conflicts.
2008-12-28Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) sched: fix warning in fs/proc/base.c schedstat: consolidate per-task cpu runtime stats sched: use RCU variant of list traversal in for_each_leaf_rt_rq() sched, cpuacct: export percpu cpuacct cgroup stats sched, cpuacct: refactoring cpuusage_read / cpuusage_write sched: optimize update_curr() sched: fix wakeup preemption clock sched: add missing arch_update_cpu_topology() call sched: let arch_update_cpu_topology indicate if topology changed sched: idle_balance() does not call load_balance_newidle() sched: fix sd_parent_degenerate on non-numa smp machine sched: add uid information to sched_debug for CONFIG_USER_SCHED sched: move double_unlock_balance() higher sched: update comment for move_task_off_dead_cpu sched: fix inconsistency when redistribute per-cpu tg->cfs_rq shares sched/rt: removed unneeded defintion sched: add hierarchical accounting to cpu accounting controller sched: include group statistics in /proc/sched_debug sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER sched: clean up SCHED_CPUMASK_ALLOC ...
2008-12-28Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits) sched, trace: update trace_sched_wakeup() tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3 Revert "x86: disable X86_PTRACE_BTS" ring-buffer: prevent false positive warning ring-buffer: fix dangling commit race ftrace: enable format arguments checking x86, bts: memory accounting x86, bts: add fork and exit handling ftrace: introduce tracing_reset_online_cpus() helper tracing: fix warnings in kernel/trace/trace_sched_switch.c tracing: fix warning in kernel/trace/trace.c tracing/ring-buffer: remove unused ring_buffer size trace: fix task state printout ftrace: add not to regex on filtering functions trace: better use of stack_trace_enabled for boot up code trace: add a way to enable or disable the stack tracer x86: entry_64 - introduce FTRACE_ frame macro v2 tracing/ftrace: add the printk-msg-only option tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp() x86, bts: correctly report invalid bts records ... Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits being already partly merged by the SH merge.
2008-12-19sched: move test_sd_parent() to an SMP section of sched.hIngo Molnar
Impact: build fix Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19sched: add SD_BALANCE_NEWIDLE at MC and CPU level for sched_mc>0Vaidyanathan Srinivasan
Impact: change task balancing to save power more agressively Add SD_BALANCE_NEWIDLE flag at MC level and CPU level if sched_mc is set. This helps power savings and will not affect performance when sched_mc=0 Ingo and Mike Galbraith have optimised the SD flags by removing SD_BALANCE_NEWIDLE at MC and CPU level. This helps performance but hurts power savings since this slows down task consolidation by reducing the number of times load_balance is run. sched: fine-tune SD_MC_INIT commit 14800984706bf6936bbec5187f736e928be5c218 Author: Mike Galbraith <efault@gmx.de> Date: Fri Nov 7 15:26:50 2008 +0100 sched: re-tune balancing -- revert commit 9fcd18c9e63e325dbd2b4c726623f760788d5aa8 Author: Ingo Molnar <mingo@elte.hu> Date: Wed Nov 5 16:52:08 2008 +0100 This patch selectively enables SD_BALANCE_NEWIDLE flag only when sched_mc is set to 1 or 2. This helps power savings by task consolidation and also does not hurt performance at sched_mc=0 where all power saving optimisations are turned off. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>