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2008-08-16Merge 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: scale sysctl_sched_shares_ratelimit with nr_cpus sched: fix rt-bandwidth hotplug race sched: fix the race between walk_tg_tree and sched_create_group
2008-08-15sched: scale sysctl_sched_shares_ratelimit with nr_cpusPeter Zijlstra
David reported that his Niagra spend a little too much time in tg_shares_up(), which considering he has a large cpu count makes sense. So scale the ratelimit value with the number of cpus like we do for other controls as well. Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15completions: uninline try_wait_for_completion and completion_doneDave Chinner
m68k fails to build with these functions inlined in completion.h. Move them out of line into sched.c and export them to avoid this problem. Signed-off-by: Dave Chinner <david@fromorbit.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-14sched: fix the race between walk_tg_tree and sched_create_groupZhang, Yanmin
With 2.6.27-rc3, I hit a kernel panic when running volanoMark on my new x86_64 machine. I also hit it with other 2.6.27-rc kernels. See below log. Basically, function walk_tg_tree and sched_create_group have a race between accessing and initiating tg->children. Below patch fixes it by moving tg->children initiation to the front of linking tg->siblings to parent->children. {----------------panic log------------} BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 IP: [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f PGD 1be1c4067 PUD 1bdd8d067 PMD 0 Oops: 0000 [1] SMP CPU 11 Modules linked in: igb Pid: 22979, comm: java Not tainted 2.6.27-rc3 #1 RIP: 0010:[<ffffffff802292ab>] [<ffffffff802292ab>] walk_tg_tree+0x45/0x7f RSP: 0018:ffff8801bfbbbd18 EFLAGS: 00010083 RAX: 0000000000000000 RBX: ffff8800be0dce40 RCX: ffffffffffffffc0 RDX: ffff880102c43740 RSI: 0000000000000000 RDI: ffff8800be0dce40 RBP: ffff8801bfbbbd48 R08: ffff8800ba437bc8 R09: 0000000000001f40 R10: ffff8801be812100 R11: ffffffff805fdf44 R12: ffff880102c43740 R13: 0000000000000000 R14: ffffffff8022cf0f R15: ffffffff8022749f FS: 00000000568ac950(0063) GS:ffff8801bfa26d00(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000001bd848000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process java (pid: 22979, threadinfo ffff8801b145a000, task ffff8801bf18e450) Stack: 0000000000000001 ffff8800ba5c8d60 0000000000000001 0000000000000001 ffff8800bad1ccb8 0000000000000000 ffff8801bfbbbd98 ffffffff8022ed37 0000000000000001 0000000000000286 ffff8801bd5ee180 ffff8800ba437bc8 Call Trace: <IRQ> [<ffffffff8022ed37>] try_to_wake_up+0x71/0x24c [<ffffffff80247177>] autoremove_wake_function+0x9/0x2e [<ffffffff80228039>] ? __wake_up_common+0x46/0x76 [<ffffffff802296d5>] __wake_up+0x38/0x4f [<ffffffff806169cc>] tcp_v4_rcv+0x380/0x62e Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-11Merge 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, 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()
2008-08-12Merge branch 'core/locking' into core/urgentIngo Molnar
2008-08-11Merge branch 'linus' into sched/urgentIngo Molnar
2008-08-11lockdep: re-annotate scheduler runqueuesPeter Zijlstra
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>
2008-08-04__sched_setscheduler: don't do any policy checks when not "user"Jeremy Fitzhardinge
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>
2008-08-01lockdep: change scheduler annotationPeter Zijlstra
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>
2008-07-30sched: make scheduler sysfs attributes sysdev class devicesAndi Kleen
They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28sched: test runtime rather than period in global_rt_runtime()roel kluin
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>
2008-07-26tracehook: wait_task_inactiveRoland McGrath
This extends wait_task_inactive() with a new argument so it can be used in a "soft" mode where it will check for the task changing state unexpectedly and back off. There is no change to existing callers. This lays the groundwork to allow robust, noninvasive tracing that can try to sample a blocked thread but back off safely if it wakes up. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26Full conversion to early_initcall() interface, remove old interfaceEduard - Gabriel Munteanu
A previous patch added the early_initcall(), to allow a cleaner hooking of pre-SMP initcalls. Now we remove the older interface, converting all existing users to the new one. [akpm@linux-foundation.org: cleanups] [akpm@linux-foundation.org: build fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] Signed-off-by: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25accounting: account for user time when updating memory integralsJonathan Lim
Adapt acct_update_integrals() to include user time when calculating the time difference. The units of acct_rss_mem1 and acct_vm_mem1 are also changed from pages-jiffies to pages-usecs to avoid calling jiffies_to_usecs() in xacct_add_tsk() which might overflow. Signed-off-by: Jonathan Lim <jlim@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-23Merge branch 'sched/for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: hrtick_enabled() should use cpu_active() sched, x86: clean up hrtick implementation sched: fix build error, provide partition_sched_domains() unconditionally sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed cpu hotplug: Make cpu_active_map synchronization dependency clear cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) sched: rework of "prioritize non-migratable tasks over migratable ones" sched: reduce stack size in isolated_cpu_setup() Revert parts of "ftrace: do not trace scheduler functions" Fixed up conflicts in include/asm-x86/thread_info.h (due to the TIF_SINGLESTEP unification vs TIF_HRTICK_RESCHED removal) and kernel/sched_fair.c (due to cpu_active_map vs for_each_cpu_mask_nr() introduction).
2008-07-23Merge branch 'cpus4096-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) NR_CPUS: Replace NR_CPUS in speedstep-centrino.c cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUP NR_CPUS: Replace NR_CPUS in cpufreq userspace routines NR_CPUS: Replace per_cpu(..., smp_processor_id()) with __get_cpu_var NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genx2apic_uv_x.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/mcheck/mce_64.c cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c, fix cpumask: Use optimized CPUMASK_ALLOC macros in the centrino_target cpumask: Provide a generic set of CPUMASK_ALLOC macros cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c cpumask: Optimize cpumask_of_cpu in drivers/misc/sgi-xp/xpc_main.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/ldt.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/io_apic_64.c cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr Revert "cpumask: introduce new APIs" cpumask: make for_each_cpu_mask a bit smaller net: Pass reference to cpumask variable in net/sunrpc/svc.c ... Fix up trivial conflicts in drivers/cpufreq/cpufreq.c manually
2008-07-21sysdev: Pass the attribute to the low level sysdev show/store functionAndi Kleen
This allow to dynamically generate attributes and share show/store functions between attributes. Right now most attributes are generated by special macros and lots of duplicated code. With the attribute passed it's instead possible to attach some data to the attribute and then use that in shared low level functions to do different things. I need this for the dynamically generated bank attributes in the x86 machine check code, but it'll allow some further cleanups. I converted all users in tree to the new show/store prototype. It's a single huge patch to avoid unbisectable sections. Runtime tested: x86-32, x86-64 Compiled only: ia64, powerpc Not compile tested/only grep converted: sh, arm, avr32 Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-20sched: hrtick_enabled() should use cpu_active()Ingo Molnar
Peter pointed out that hrtick_enabled() should use cpu_active(). Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-20Merge branch 'sched/urgent' into sched/develIngo Molnar
2008-07-20sched, x86: clean up hrtick implementationPeter Zijlstra
random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Mihai Moldovan <ionic@ionic.de> Cc: Michal Januszewski <spock@gentoo.org> Cc: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment ↵Max Krasnyansky
(take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Gregory Haskins <ghaskins@novell.com> Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18sched: reduce stack size in isolated_cpu_setup()Mike Travis
* Remove 16k stack requirements in isolated_cpu_setup when NR_CPUS=4096. Signed-off-by: Mike Travis <travis@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16Merge branch 'linus' into cpus4096Ingo Molnar
Conflicts: arch/x86/xen/smp.c kernel/sched_rt.c net/iucv/iucv.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14Merge branch 'core/softirq' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core/softirq' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: softirq: remove irqs_disabled warning from local_bh_enable softirq: remove initialization of static per-cpu variable Remove argument from open_softirq which is always NULL
2008-07-14Merge branch 'sched/new-API-sched_setscheduler' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched/new-API-sched_setscheduler' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: add new API sched_setscheduler_nocheck: add a flag to control access checks
2008-07-14Merge branch 'auto-ftrace-next' into tracing/for-linusIngo Molnar
Conflicts: arch/x86/kernel/entry_32.S arch/x86/kernel/process_32.c arch/x86/kernel/process_64.c arch/x86/lib/Makefile include/asm-x86/irqflags.h kernel/Makefile kernel/sched.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-14Merge branch 'sched/for-linus' into tracing/for-linusIngo Molnar
2008-07-13Merge branch 'linus' into sched/develIngo Molnar
2008-07-12Merge branch 'linus' into x86/coreIngo Molnar
Conflicts: arch/x86/mm/ioremap.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10sched: fix cpu hotplug, cleanupLinus Torvalds
Clean up __migrate_task(): to just have separate "done" and "fail" cases, instead of that "out" case with random error behavior. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-10Merge branch 'tracing/ftrace' into auto-ftrace-nextIngo Molnar
2008-07-10sched: fix cpu hotplugDmitry Adamushko
I think we may have a race between try_to_wake_up() and migrate_live_tasks() -> move_task_off_dead_cpu() when the later one may end up looping endlessly. Interrupts are enabled on other CPUs when migration_call(CPU_DEAD, ...) is called so we may get a race between try_to_wake_up() and migrate_live_tasks() -> move_task_off_dead_cpu(). The former one may push a task out of a dead CPU causing the later one to loop endlessly. Heiko Carstens observed: | That's exactly what explains a dump I got yesterday. Thanks for fixing! :) Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: miaox@cn.fujitsu.com Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Avi Kivity <avi@qumranet.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08sched, numa: replace MAX_NUMNODES with nr_node_ids in kernel/sched.cMike Travis
* Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c, where appropriate. This saves some allocated space as well as many wasted cycles going through node entries that are non-existent. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-07Merge commit 'v2.6.26-rc9' into sched/develIngo Molnar
2008-07-06Merge commit 'v2.6.26-rc9' into cpus4096Ingo Molnar
2008-07-04sched: fix accounting in task delay accounting & migrationAnkita Garg
On Thu, Jun 19, 2008 at 12:27:14PM +0200, Peter Zijlstra wrote: > On Thu, 2008-06-05 at 10:50 +0530, Ankita Garg wrote: > > > Thanks Peter for the explanation... > > > > I agree with the above and that is the reason why I did not see weird > > values with cpu_time. But, run_delay still would suffer skews as the end > > points for delta could be taken on different cpus due to migration (more > > so on RT kernel due to the push-pull operations). With the below patch, > > I could not reproduce the issue I had seen earlier. After every dequeue, > > we take the delta and start wait measurements from zero when moved to a > > different rq. > > OK, so task delay delay accounting is broken because it doesn't take > migration into account. > > What you've done is make it symmetric wrt enqueue, and account it like > > cpu0 cpu1 > > enqueue > <wait-d1> > dequeue > enqueue > <wait-d2> > run > > Where you add both d1 and d2 to the run_delay,.. right? > Thanks for reviewing the patch. The above is exactly what I have done. > This seems like a good fix, however it looks like the patch will break > compilation in !CONFIG_SCHEDSTATS && !CONFIG_TASK_DELAY_ACCT, of it > failing to provide a stub for sched_info_dequeue() in that case. Fixed. Pl. find the new patch below. Signed-off-by: Ankita Garg <ankita@in.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Gregory Haskins <ghaskins@novell.com> Cc: rostedt@goodmis.org Cc: suresh.b.siddha@intel.com Cc: aneesh.kumar@linux.vnet.ibm.com Cc: dhaval@linux.vnet.ibm.com Cc: vatsa@linux.vnet.ibm.com Cc: David Bahi <DBahi@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-04sched: add avg-overlap support to RT tasksGregory Haskins
We have the notion of tracking process-coupling (a.k.a. buddy-wake) via the p->se.last_wake / p->se.avg_overlap facilities, but it is only used for cfs to cfs interactions. There is no reason why an rt to cfs interaction cannot share in establishing a relationhip in a similar manner. Because PREEMPT_RT runs many kernel threads as FIFO priority, we often times have heavy interaction between RT threads waking CFS applications. This patch offers a substantial boost (50-60%+) in perfomance under those circumstances. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: npiggin@suse.de Cc: rostedt@goodmis.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-04sched: terminate newidle balancing once at least one task has moved overGregory Haskins
Inspired by Peter Zijlstra. Signed-off-by: Gregory Haskins <ghaskins@novell.com> Cc: npiggin@suse.de Cc: rostedt@goodmis.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01sched: fix divide error when trying to configure rt_period to zeroRaistlin
Here it is another little Oops we found while configuring invalid values via cgroups: echo 0 > /dev/cgroups/0/cpu.rt_period_us or echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us [ 205.509825] divide error: 0000 [#1] [ 205.510151] Modules linked in: [ 205.510151] [ 205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33) [ 205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0 [ 205.510151] EIP is at div64_u64+0x5f/0x70 [ 205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000 [ 205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50 [ 205.510151] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000) [ 205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000 [ 205.510151] c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0 [ 205.510151] c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea [ 205.510151] Call Trace: [ 205.510151] [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240 [ 205.510151] [<c0242bd8>] ? cgroup_file_open+0x18/0xe0 [ 205.510151] [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0 [ 205.510151] [<c0215066>] ? sched_group_set_rt_period+0x36/0x50 [ 205.510151] [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10 [ 205.510151] [<c0242dc5>] ? cgroup_file_write+0x125/0x160 [ 205.510151] [<c0232c15>] ? hrtimer_interrupt+0x155/0x190 [ 205.510151] [<c02f047f>] ? security_file_permission+0xf/0x20 [ 205.510151] [<c0277ad8>] ? rw_verify_area+0x48/0xc0 [ 205.510151] [<c0283744>] ? dupfd+0x104/0x130 [ 205.510151] [<c027838c>] ? vfs_write+0x9c/0x160 [ 205.510151] [<c0242ca0>] ? cgroup_file_write+0x0/0x160 [ 205.510151] [<c027850d>] ? sys_write+0x3d/0x70 [ 205.510151] [<c0203019>] ? sysenter_past_esp+0x6a/0x91 [ 205.510151] ======================= [ 205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56 [ 205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50 The attached patch solves the issue for me. I'm checking as soon as possible for the period not being zero since, if it is, going ahead is useless. This way we also save a mutex_lock() and a read_lock() wrt doing it inside tg_set_bandwidth() or __rt_schedulable(). Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-30sched: fix warningVegard Nossum
This patch fixes the following warning: kernel/sched.c:1667: warning: 'cfs_rq_set_shares' defined but not used This seems the correct way to fix this; cfs_rq_set_shares() is only used in a single place, which is also inside #ifdef CONFIG_FAIR_GROUP_SCHED. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-30sched: build fixIngo Molnar
fix: kernel/sched.c: In function ‘sched_group_set_shares': kernel/sched.c:8635: error: implicit declaration of function ‘cfs_rq_set_shares' Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-29sched: fix cpu hotplugDmitry Adamushko
the CPU hotplug problems (crashes under high-volume unplug+replug tests) seem to be related to migrate_dead_tasks(). Firstly I added traces to see all tasks being migrated with migrate_live_tasks() and migrate_dead_tasks(). On my setup the problem pops up (the one with "se == NULL" in the loop of pick_next_task_fair()) shortly after the traces indicate that some has been migrated with migrate_dead_tasks()). btw., I can reproduce it much faster now with just a plain cpu down/up loop. [disclaimer] Well, unless I'm really missing something important in this late hour [/desclaimer] pick_next_task() is not something appropriate for migrate_dead_tasks() :-) the following change seems to eliminate the problem on my setup (although, I kept it running only for a few minutes to get a few messages indicating migrate_dead_tasks() does move tasks and the system is still ok) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: incremental effective_load()Peter Zijlstra
Increase the accuracy of the effective_load values. Not only consider the current increment (as per the attempted wakeup), but also consider the delta between when we last adjusted the shares and the current situation. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: correct wakeup weight calculationsPeter Zijlstra
rw_i = {2, 4, 1, 0} s_i = {2/7, 4/7, 1/7, 0} wakeup on cpu0, weight=1 rw'_i = {3, 4, 1, 0} s'_i = {3/8, 4/8, 1/8, 0} s_0 = S * rw_0 / \Sum rw_j -> \Sum rw_j = S*rw_0/s_0 = 1*2*7/2 = 7 (correct) s'_0 = S * (rw_0 + 1) / (\Sum rw_j + 1) = 1 * (2+1) / (7+1) = 3/8 (correct so we find that adding 1 to cpu0 gains 5/56 in weight if say the other cpu were, cpu1, we'd also have to calculate its 4/56 loss Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: update shares on wakeupPeter Zijlstra
We found that the affine wakeup code needs rather accurate load figures to be effective. The trouble is that updating the load figures is fairly expensive with group scheduling. Therefore ratelimit the updating. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: fix shares boost logicPeter Zijlstra
In case the domain is empty, pretend there is a single task on each cpu, so that together with the boost logic we end up giving 1/n shares to each cpu. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: disable source/target_load biasPeter Zijlstra
The bias given by source/target_load functions can be very large, disable it by default to get faster convergence. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: remove prio preference from balance decisionsPeter Zijlstra
Priority looses much of its meaning in a hierarchical context. So don't use it in balance decisions. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-27sched: hierarchical load vs find_busiest_groupPeter Zijlstra
find_busiest_group() has some assumptions about task weight being in the NICE_0_LOAD range. Hierarchical task groups break this assumption - fix this by replacing it with the average task weight, which will adapt the situation. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>