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* sched: Remove FAIR_SLEEPERS featureMike Galbraith2010-03-112-8/+1Star
| | | | | | | | | | Our preemption model relies too heavily on sleeper fairness to disable it without dire consequences. Remove the feature, and save a branch or two. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301520.6785.40.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Remove NORMALIZED_SLEEPERMike Galbraith2010-03-112-17/+0Star
| | | | | | | | | This feature hasn't been enabled in a long time, remove effectively dead code. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301447.6785.38.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Fix select_idle_sibling()Mike Galbraith2010-03-111-4/+10
| | | | | | | | | | | Don't bother with selection when the current cpu is idle. Recent load balancing changes also make it no longer necessary to check wake_affine() success before returning the selected sibling, so we now always use it. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301369.6785.36.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Tweak sched_latency and min_granularityMike Galbraith2010-03-111-6/+6
| | | | | | | | | | | | Allow LAST_BUDDY to kick in sooner, improving cache utilization as soon as a second buddy pair arrives on scene. The cost is latency starting to climb sooner, the tbenefit for tbench 8 on my Q6600 box is ~2%. No detrimental effects noted in normal idesktop usage. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301285.6785.34.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Cleanup/optimize clock updatesMike Galbraith2010-03-112-18/+16Star
| | | | | | | | | | | | | | | | Now that we no longer depend on the clock being updated prior to enqueueing on migratory wakeup, we can clean up a bit, placing calls to update_rq_clock() exactly where they are needed, ie on enqueue, dequeue and schedule events. In the case of a freshly enqueued task immediately preempting, we can skip the update during preemption, as the clock was just updated by the enqueue event. We also save an unneeded call during a migratory wakeup by not updating the previous runqueue, where update_curr() won't be invoked. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301199.6785.32.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Remove avg_overlapMike Galbraith2010-03-114-68/+0Star
| | | | | | | | | | | | | | | | | | | | | Both avg_overlap and avg_wakeup had an inherent problem in that their accuracy was detrimentally affected by cross-cpu wakeups, this because we are missing the necessary call to update_curr(). This can't be fixed without increasing overhead in our already too fat fastpath. Additionally, with recent load balancing changes making us prefer to place tasks in an idle cache domain (which is good for compute bound loads), communicating tasks suffer when a sync wakeup, which would enable affine placement, is turned into a non-sync wakeup by SYNC_LESS. With one task on the runqueue, wake_affine() rejects the affine wakeup request, leaving the unfortunate where placed, taking frequent cache misses. Remove it, and recover some fastpath cycles. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301121.6785.30.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Remove avg_wakeupMike Galbraith2010-03-114-60/+4Star
| | | | | | | | | | | Testing the load which led to this heuristic (nfs4 kbuild) shows that it has outlived it's usefullness. With intervening load balancing changes, I cannot see any difference with/without, so recover there fastpath cycles. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301062.6785.29.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Rate-limit nohzMike Galbraith2010-03-112-0/+15
| | | | | | | | | | | | | | | Entering nohz code on every micro-idle is costing ~10% throughput for netperf TCP_RR when scheduling cross-cpu. Rate limiting entry fixes this, but raises ticks a bit. On my Q6600, an idle box goes from ~85 interrupts/sec to 128. The higher the context switch rate, the more nohz entry costs. With this patch and some cycle recovery patches in my tree, max cross cpu context switch rate is improved by ~16%, a large portion of which of which is this ratelimiting. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301003.6785.28.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Implement group scheduler statistics in one structLucas De Marchi2010-03-114-134/+81Star
| | | | | | | | | | | | | Put all statistic fields of sched_entity in one struct, sched_statistics, and embed it into sched_entity. This change allows to memset the sched_statistics to 0 when needed (for instance when forking), avoiding bugs of non initialized fields. Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Fix pick_next_highest_task_rt() for cgroupsPeter Zijlstra2010-03-111-1/+6
| | | | | | | | | | | Since pick_next_highest_task_rt() already iterates all the cgroups and is really only interested in tasks, skip over the !task entries. Reported-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Dhaval Giani <dhaval.giani@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: Cleanup: remove unused variable in try_to_wake_up()Dan Carpenter2010-03-111-2/+2
| | | | | | | | | | | | | We haven't used the "orig_rq" variable since 055a00865d "Fix/add missing update_rq_clock() calls" Signed-off-by: Dan Carpenter <error27@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Gautham R Shenoy <ego@in.ibm.com> Cc: efault@gmx.de LKML-Reference: <20100306111752.GL4958@bicker> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'for-2.6.34' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-03-011-2/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.34' of git://git.kernel.dk/linux-2.6-block: (38 commits) block: don't access jiffies when initialising io_context cfq: remove 8 bytes of padding from cfq_rb_root on 64 bit builds block: fix for "Consolidate phys_segment and hw_segment limits" cfq-iosched: quantum check tweak blktrace: perform cleanup after setup error blkdev: fix merge_bvec_fn return value checks cfq-iosched: requests "in flight" vs "in driver" clarification cciss: Fix problem with scatter gather elements in the scsi half of the driver cciss: eliminate unnecessary pointer use in cciss scsi code cciss: do not use void pointer for scsi hba data cciss: factor out scatter gather chain block mapping code cciss: fix scatter gather chain block dma direction kludge cciss: simplify scatter gather code cciss: factor out scatter gather chain block allocation and freeing cciss: detect bad alignment of scsi commands at build time cciss: clarify command list padding calculation cfq-iosched: rethink seeky detection for SSDs cfq-iosched: rework seeky detection block: remove padding from io_context on 64bit builds block: Consolidate phys_segment and hw_segment limits ...
| * blktrace: perform cleanup after setup errorDmitry Monakhov2010-02-281-2/+3
| | | | | | | | | | | | | | | | | | | | Currently even if BLKTRACESETUP ioctl has failed user must call BLKTRACETEARDOWN to be shure what all staff was cleaned, which is contr-intuitive. Let's setup ioctl make necessery cleanup by it self. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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*---. \ Merge branches 'futexes-for-linus', 'irq-core-for-linus' and ↵Linus Torvalds2010-03-011-3/+3
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'bkl-drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: Protect pid lookup in compat code with RCU * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Fix documentation of default chip disable() * 'bkl-drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nvram: Drop the BKL from nvram_open()
| * | | | futex: Protect pid lookup in compat code with RCUThomas Gleixner2009-12-091-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_task_by_vpid() in compat_sys_get_robust_list() does not require tasklist_lock. It can be protected with rcu_read_lock as done in sys_get_robust_list() already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org>
* | | | | Merge branch 'timers-for-linus' of ↵Linus Torvalds2010-03-014-7/+20
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: posix-timers.c: Don't export local functions clocksource: start CMT at clocksource resume clocksource: add suspend callback clocksource: add argument to resume callback ntp: Cleanup xtime references in ntp.c ntp: Make time_esterror and time_maxerror static
| * | | | | posix-timers.c: Don't export local functionsH Hartley Sweeten2010-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | clocksource: add suspend callbackMagnus Damm2010-02-052-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a clocksource suspend callback. This callback can be used by the clocksource driver to shutdown and perform any kind of late suspend activities even though the clocksource driver itself is a non-sysdev driver. One example where this is useful is to fix the sh_cmt.c platform driver that today suspends using the platform bus and shuts down the clocksource too early. With this callback in place the sh_cmt driver will suspend using the clocksource and clockevent hooks and leave the platform device pm callbacks unused. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | clocksource: add argument to resume callbackMagnus Damm2010-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the clocksource as an argument to the clocksource resume callback. Needed so we can point out which CMT channel the sh_cmt.c driver shall resume. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: john stultz <johnstul@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | ntp: Cleanup xtime references in ntp.cJohn Stultz2010-01-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ntp.c doesn't need to access timekeeping internals directly, so change xtime references to use the get_seconds() timekeeping interface. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: richard@rsk.demon.co.uk LKML-Reference: <1264738844-21935-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | ntp: Make time_esterror and time_maxerror staticjohn stultz2010-01-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make time_esterror and time_maxerror static as no one uses them outside of ntp.c Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: richard@rsk.demon.co.uk LKML-Reference: <1264719761.3437.47.camel@localhost.localdomain> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | | Merge branch 'x86-ptrace-for-linus' of ↵Linus Torvalds2010-02-281-0/+88
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-ptrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, ptrace: Remove set_stopped_child_used_math() in [x]fpregs_set x86, ptrace: Simplify xstateregs_get() ptrace: Fix ptrace_regset() comments and diagnose errors specifically parisc: Disable CONFIG_HAVE_ARCH_TRACEHOOK ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET x86, ptrace: regset extensions to support xstate
| * | | | | | ptrace: Fix ptrace_regset() comments and diagnose errors specificallySuresh Siddha2010-02-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return -EINVAL for the bad size and for unrecognized NT_* type in ptrace_regset() instead of -EIO. Also update the comments for this ptrace interface with more clarifications. Requested-by: Roland McGrath <roland@redhat.com> Requested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <20100222225240.397523600@sbs-t61.sc.intel.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | | | | ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSETSuresh Siddha2010-02-121-0/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generic support for PTRACE_GETREGSET/PTRACE_SETREGSET commands which export the regsets supported by each architecture using the correponding NT_* types. These NT_* types are already part of the userland ABI, used in representing the architecture specific register sets as different NOTES in an ELF core file. 'addr' parameter for the ptrace system call encode the REGSET type (using the corresppnding NT_* type) and the 'data' parameter points to the struct iovec having the user buffer and the length of that buffer. struct iovec iov = { buf, len}; ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); On successful completion, iov.len will be updated by the kernel specifying how much the kernel has written/read to/from the user's iov.buf. x86 extended state registers are primarily exported using this interface. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> LKML-Reference: <20100211195614.886724710@sbs-t61.sc.intel.com> Acked-by: Hongjiu Lu <hjl.tools@gmail.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | | | | | | Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2010-02-281-0/+13
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, mm: Unify kernel_physical_mapping_init() API x86, mm: Allow highmem user page tables to be disabled at boot time x86: Do not reserve brk for DMI if it's not going to be used x86: Convert tlbstate_lock to raw_spinlock x86: Use the generic page_is_ram() x86: Remove BIOS data range from e820 Move page_is_ram() declaration to mm.h Generic page_is_ram: use __weak resources: introduce generic page_is_ram()
| * \ \ \ \ \ \ Merge branch 'linus' into x86/mmThomas Gleixner2010-02-17132-5977/+12188
| |\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86/mm is on 32-rc4 and missing the spinlock namespace changes which are needed for further commits into this topic. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | Generic page_is_ram: use __weakAndrew Morton2010-02-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use __weak instead of __attribute__((weak)). Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | | | | | | | resources: introduce generic page_is_ram()Wu Fengguang2010-02-021-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's based on walk_system_ram_range(), for archs that don't have their own page_is_ram(). The static verions in MIPS and SCORE are also made global. v4: prefer plain 1 instead of PAGE_IS_RAM (H. Peter Anvin) v3: add comment (KAMEZAWA Hiroyuki) "AFAIK, this "System RAM" information has been used for kdump to grab valid memory area and seems good for the kernel itself." v2: add PAGE_IS_RAM macro (Américo Wang) Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Américo Wang <xiyou.wangcong@gmail.com> Cc: linux-mips@linux-mips.org Cc: Yinghai Lu <yinghai@kernel.org> Acked-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> LKML-Reference: <20100122081619.GA6431@localhost> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | | | | | | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2010-02-289-2440/+1785Star
|\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: (25 commits) sched: Fix SCHED_MC regression caused by change in sched cpu_power sched: Don't use possibly stale sched_class kthread, sched: Remove reference to kthread_create_on_cpu sched: cpuacct: Use bigger percpu counter batch values for stats counters percpu_counter: Make __percpu_counter_add an inline function on UP sched: Remove member rt_se from struct rt_rq sched: Change usage of rt_rq->rt_se to rt_rq->tg->rt_se[cpu] sched: Remove unused update_shares_locked() sched: Use for_each_bit sched: Queue a deboosted task to the head of the RT prio queue sched: Implement head queueing for sched_rt sched: Extend enqueue_task to allow head queueing sched: Remove USER_SCHED sched: Fix the place where group powers are updated sched: Assume *balance is valid sched: Remove load_balance_newidle() sched: Unify load_balance{,_newidle}() sched: Add a lock break for PREEMPT=y sched: Remove from fwd decls sched: Remove rq_iterator from move_one_task ... Fix up trivial conflicts in kernel/sched.c
| * | | | | | | | | sched: Fix SCHED_MC regression caused by change in sched cpu_powerSuresh Siddha2010-02-261-33/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On platforms like dual socket quad-core platform, the scheduler load balancer is not detecting the load imbalances in certain scenarios. This is leading to scenarios like where one socket is completely busy (with all the 4 cores running with 4 tasks) and leaving another socket completely idle. This causes performance issues as those 4 tasks share the memory controller, last-level cache bandwidth etc. Also we won't be taking advantage of turbo-mode as much as we would like, etc. Some of the comparisons in the scheduler load balancing code are comparing the "weighted cpu load that is scaled wrt sched_group's cpu_power" with the "weighted average load per task that is not scaled wrt sched_group's cpu_power". While this has probably been broken for a longer time (for multi socket numa nodes etc), the problem got aggrevated via this recent change: | | commit f93e65c186ab3c05ce2068733ca10e34fd00125e | Author: Peter Zijlstra <a.p.zijlstra@chello.nl> | Date: Tue Sep 1 10:34:32 2009 +0200 | | sched: Restore __cpu_power to a straight sum of power | Also with this change, the sched group cpu power alone no longer reflects the group capacity that is needed to implement MC, MT performance (default) and power-savings (user-selectable) policies. We need to use the computed group capacity (sgs.group_capacity, that is computed using the SD_PREFER_SIBLING logic in update_sd_lb_stats()) to find out if the group with the max load is above its capacity and how much load to move etc. Reported-by: Ma Ling <ling.ma@intel.com> Initial-Analysis-by: Zhang, Yanmin <yanmin_zhang@linux.intel.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> [ -v2: build fix ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> # [2.6.32.x, 2.6.33.x] LKML-Reference: <1266970432.11588.22.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | sched: Don't use possibly stale sched_classThomas Gleixner2010-02-171-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | setscheduler() saves task->sched_class outside of the rq->lock held region for a check after the setscheduler changes have become effective. That might result in checking a stale value. rtmutex_setprio() has the same problem, though it is protected by p->pi_lock against setscheduler(), but for correctness sake (and to avoid bad examples) it needs to be fixed as well. Retrieve task->sched_class inside of the rq->lock held region. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org
| * | | | | | | | | Merge branch 'sched/urgent' into sched/coreThomas Gleixner2010-02-162-29/+59
| |\ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: kernel/sched.c Necessary due to the urgent fixes which conflict with the code move from sched.c to sched_fair.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | | | | | | | kthread, sched: Remove reference to kthread_create_on_cpuAnton Blanchard2010-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kthread_create_on_cpu doesn't exist so update a comment in kthread.c to reflect this. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100209040740.GB3702@kryten> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | sched: cpuacct: Use bigger percpu counter batch values for stats countersAnton Blanchard2010-02-081-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT are enabled we can call cpuacct_update_stats with values much larger than percpu_counter_batch. This means the call to percpu_counter_add will always add to the global count which is protected by a spinlock and we end up with a global spinlock in the scheduler. Based on an idea by KOSAKI Motohiro, this patch scales the batch value by cputime_one_jiffy such that we have the same batch limit as we would if CONFIG_VIRT_CPU_ACCOUNTING was disabled. His patch did this once at boot but that initialisation happened too early on PowerPC (before time_init) and it was never updated at runtime as a result of a hotplug cpu add/remove. This patch instead scales percpu_counter_batch by cputime_one_jiffy at runtime, which keeps the batch correct even after cpu hotplug operations. We cap it at INT_MAX in case of overflow. For architectures that do not support CONFIG_VIRT_CPU_ACCOUNTING, cputime_one_jiffy is the constant 1 and gcc is smart enough to optimise min(s32 percpu_counter_batch, INT_MAX) to just percpu_counter_batch at least on x86 and PowerPC. So there is no need to add an #ifdef. On a 64 thread PowerPC box with CONFIG_VIRT_CPU_ACCOUNTING and CONFIG_CGROUP_CPUACCT enabled, a context switch microbenchmark is 234x faster and almost matches a CONFIG_CGROUP_CPUACCT disabled kernel: CONFIG_CGROUP_CPUACCT disabled: 16906698 ctx switches/sec CONFIG_CGROUP_CPUACCT enabled: 61720 ctx switches/sec CONFIG_CGROUP_CPUACCT + patch: 16663217 ctx switches/sec Tested with: wget http://ozlabs.org/~anton/junkcode/context_switch.c make context_switch for i in `seq 0 63`; do taskset -c $i ./context_switch & done vmstat 1 Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | Merge branch 'sched/urgent' into sched/coreIngo Molnar2010-02-0832-296/+464
| |\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: Merge dependent fix, update to latest -rc. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Remove member rt_se from struct rt_rqYong Zhang2010-02-041-2/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's a duplicate of tg->rt_se[cpu] and the only usage is sched_rt_rq_dequeue() and sched_rt_rq_enqueue(). After the first patch to those two function. rt_se can be removed. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <2674af741001282258q38781619u653ca4a7dd267347@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Change usage of rt_rq->rt_se to rt_rq->tg->rt_se[cpu]Yong Zhang2010-02-041-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the first step to remove rt_rq member rt_se because it have the same meaning with tg->rt_se[cpu]. And the latter style is also used by the fair scheduling class. Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <2674af741001282257r28c97a92o9f90cf16fe8d3d84@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Remove unused update_shares_locked()Peter Zijlstra2010-02-021-14/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f492e12ef050e02bf0185b6b57874992591b9be1 ("sched: Remove load_balance_newidle()") removed the only user of this function, so remove it too. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1265019219.24455.128.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Use for_each_bitAkinobu Mita2010-02-021-3/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No change in functionality. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <1264938810-4173-1-git-send-email-akinobu.mita@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Queue a deboosted task to the head of the RT prio queueThomas Gleixner2010-01-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rtmutex_set_prio() is used to implement priority inheritance for futexes. When a task is deboosted it gets enqueued at the tail of its RT priority list. This is violating the POSIX scheduling semantics: rt priority list X contains two runnable tasks A and B task A runs with priority X and holds mutex M task C preempts A and is blocked on mutex M -> task A is boosted to priority of task C (Y) task A unlocks the mutex M and deboosts itself -> A is dequeued from rt priority list Y -> A is enqueued to the tail of rt priority list X task C schedules away task B runs This is wrong as task A did not schedule away and therefor violates the POSIX scheduling semantics. Enqueue the task to the head of the priority list instead. Reported-by: Mathias Weber <mathias.weber.mw1@roche.com> Reported-by: Carsten Emde <cbe@osadl.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Carsten Emde <cbe@osadl.org> Tested-by: Mathias Weber <mathias.weber.mw1@roche.com> LKML-Reference: <20100120171629.809074113@linutronix.de>
| * | | | | | | | | | | sched: Implement head queueing for sched_rtThomas Gleixner2010-01-221-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ability of enqueueing a task to the head of a SCHED_FIFO priority list is required to fix some violations of POSIX scheduling policy. Implement the functionality in sched_rt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Carsten Emde <cbe@osadl.org> Tested-by: Mathias Weber <mathias.weber.mw1@roche.com> LKML-Reference: <20100120171629.772169931@linutronix.de>
| * | | | | | | | | | | sched: Extend enqueue_task to allow head queueingThomas Gleixner2010-01-223-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ability of enqueueing a task to the head of a SCHED_FIFO priority list is required to fix some violations of POSIX scheduling policy. Extend the related functions with a "head" argument. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Carsten Emde <cbe@osadl.org> Tested-by: Mathias Weber <mathias.weber.mw1@roche.com> LKML-Reference: <20100120171629.734886007@linutronix.de>
| * | | | | | | | | | | sched: Remove USER_SCHEDDhaval Giani2010-01-214-425/+7Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the USER_SCHED feature. It has been scheduled to be removed in 2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2 Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1263990378.24844.3.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Fix the place where group powers are updatedGautham R Shenoy2010-01-211-4/+3Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to update the sched_group_powers when balance_cpu == this_cpu. Currently the group powers are updated only if the balance_cpu is the first CPU in the local group. But balance_cpu = this_cpu could also be the first idle cpu in the group. Hence fix the place where the group powers are updated. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Joel Schopp <jschopp@austin.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1264017764.5717.127.camel@jschopp-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Assume *balance is validPeter Zijlstra2010-01-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since all load_balance() callers will have !NULL balance parameters we can now assume so and remove a few checks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Remove load_balance_newidle()Peter Zijlstra2010-01-211-122/+13Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The two functions: load_balance{,_newidle}() are very similar, with the following differences: - rq->lock usage - sb->balance_interval updates - *balance check So remove the load_balance_newidle() call with load_balance(.idle = CPU_NEWLY_IDLE), explicitly unlock the rq->lock before calling (would be done by double_lock_balance() anyway), and ignore the other differences for now. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Unify load_balance{,_newidle}()Peter Zijlstra2010-01-211-56/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | load_balance() and load_balance_newidle() look remarkably similar, one key point they differ in is the condition on when to active balance. So split out that logic into a separate function. One side effect is that previously load_balance_newidle() used to fail and return -1 under these conditions, whereas now it doesn't. I've not yet fully figured out the whole -1 return case for either load_balance{,_newidle}(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Add a lock break for PREEMPT=yPeter Zijlstra2010-01-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since load-balancing can hold rq->locks for quite a long while, allow breaking out early when there is lock contention. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Remove from fwd declsPeter Zijlstra2010-01-211-67/+60Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move code around to get rid of fwd declarations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | | sched: Remove rq_iterator from move_one_taskPeter Zijlstra2010-01-211-110/+36Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Again, since we only iterate the fair class, remove the abstraction. Since this is the last user of the rq_iterator, remove all that too. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-10-12 21:27:55 +0200