- 11 12月, 2012 1 次提交
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由 Peter Zijlstra 提交于
NOTE: This patch is based on "sched, numa, mm: Add fault driven placement and migration policy" but as it throws away all the policy to just leave a basic foundation I had to drop the signed-offs-by. This patch creates a bare-bones method for setting PTEs pte_numa in the context of the scheduler that when faulted later will be faulted onto the node the CPU is running on. In itself this does nothing useful but any placement policy will fundamentally depend on receiving hints on placement from fault context and doing something intelligent about it. Signed-off-by: NMel Gorman <mgorman@suse.de> Acked-by: NRik van Riel <riel@redhat.com>
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- 13 9月, 2012 1 次提交
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由 Vincent Guittot 提交于
Heteregeneous ARM platform uses arch_scale_freq_power function to reflect the relative capacity of each core Signed-off-by: NVincent Guittot <vincent.guittot@linaro.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1341826026-6504-6-git-send-email-vincent.guittot@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 04 9月, 2012 1 次提交
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由 Namhyung Kim 提交于
Commit beac4c7e ("sched: Remove AFFINE_WAKEUPS feature") removed use of the flag but left the definition. Get rid of it. Signed-off-by: NNamhyung Kim <namhyung@kernel.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/1345090865-20851-1-git-send-email-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 26 4月, 2012 1 次提交
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由 Peter Zijlstra 提交于
Commits 367456c7 ("sched: Ditch per cgroup task lists for load-balancing") and 5d6523eb ("sched: Fix load-balance wreckage") left some more wreckage. By setting loop_max unconditionally to ->nr_running load-balancing could take a lot of time on very long runqueues (hackbench!). So keep the sysctl as max limit of the amount of tasks we'll iterate. Furthermore, the min load filter for migration completely fails with cgroups since inequality in per-cpu state can easily lead to such small loads :/ Furthermore the change to add new tasks to the tail of the queue instead of the head seems to have some effect.. not quite sure I understand why. Combined these fixes solve the huge hackbench regression reported by Tim when hackbench is ran in a cgroup. Reported-by: NTim Chen <tim.c.chen@linux.intel.com> Acked-by: NTim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1335365763.28150.267.camel@twins [ got rid of the CONFIG_PREEMPT tuning and made small readability edits ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 07 12月, 2011 1 次提交
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由 Peter Zijlstra 提交于
Now that we initialize jump_labels before sched_init() we can use them for the debug features without having to worry about a window where they have the wrong setting. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-vpreo4hal9e0kzqmg5y0io2k@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 17 11月, 2011 1 次提交
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由 Peter Zijlstra 提交于
There's too many sched*.[ch] files in kernel/, give them their own directory. (No code changed, other than Makefile glue added.) Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 14 11月, 2011 1 次提交
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由 Peter Zijlstra 提交于
Normally the RT bandwidth scheme will share bandwidth across the entire root_domain. However sometimes its convenient to disable this sharing for debug purposes. Provide a simple feature switch to this end. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 14 8月, 2011 1 次提交
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由 Yong Zhang 提交于
Remove the WAKEUP_PREEMPT feature, disabling it doesn't make any sense and its outlived its use by a long long while. Signed-off-by: NYong Zhang <yong.zhang0@gmail.com> Acked-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110729082033.GB12106@zhySigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 21 7月, 2011 1 次提交
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由 Peter Zijlstra 提交于
Allow for sched_domain spans that overlap by giving such domains their own sched_group list instead of sharing the sched_groups amongst each-other. This is needed for machines with more than 16 nodes, because sched_domain_node_span() will generate a node mask from the 16 nearest nodes without regard if these masks have any overlap. Currently sched_domains have a sched_group that maps to their child sched_domain span, and since there is no overlap we share the sched_group between the sched_domains of the various CPUs. If however there is overlap, we would need to link the sched_group list in different ways for each cpu, and hence sharing isn't possible. In order to solve this, allocate private sched_groups for each CPU's sched_domain but have the sched_groups share a sched_group_power structure such that we can uniquely track the power. Reported-and-tested-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-08bxqw9wis3qti9u5inifh3y@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>
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- 14 7月, 2011 1 次提交
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由 Glauber Costa 提交于
This patch makes update_rq_clock() aware of steal time. The mechanism of operation is not different from irq_time, and follows the same principles. This lives in a CONFIG option itself, and can be compiled out independently of the rest of steal time reporting. The effect of disabling it is that the scheduler will still report steal time (that cannot be disabled), but won't use this information for cpu power adjustments. Everytime update_rq_clock_task() is invoked, we query information about how much time was stolen since last call, and feed it into sched_rt_avg_update(). Although steal time reporting in account_process_tick() keeps track of the last time we read the steal clock, in prev_steal_time, this patch do it independently using another field, prev_steal_time_rq. This is because otherwise, information about time accounted in update_process_tick() would never reach us in update_rq_clock(). Signed-off-by: NGlauber Costa <glommer@redhat.com> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Tested-by: NEric B Munson <emunson@mgebm.net> CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> CC: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
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- 14 4月, 2011 1 次提交
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由 Peter Zijlstra 提交于
Now that we've removed the rq->lock requirement from the first part of ttwu() and can compute placement without holding any rq->lock, ensure we execute the second half of ttwu() on the actual cpu we want the task to run on. This avoids having to take rq->lock and doing the task enqueue remotely, saving lots on cacheline transfers. As measured using: http://oss.oracle.com/~mason/sembench.c $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ; do echo performance > $i; done $ echo 4096 32000 64 128 > /proc/sys/kernel/sem $ ./sembench -t 2048 -w 1900 -o 0 unpatched: run time 30 seconds 647278 worker burns per second patched: run time 30 seconds 816715 worker burns per second Reviewed-by: NFrank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152729.515897185@chello.nl
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- 18 11月, 2010 1 次提交
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由 Peter Zijlstra 提交于
By tracking a per-cpu load-avg for each cfs_rq and folding it into a global task_group load on each tick we can rework tg_shares_up to be strictly per-cpu. This should improve cpu-cgroup performance for smp systems significantly. [ Paul: changed to use queueing cfs_rq + bug fixes ] Signed-off-by: NPaul Turner <pjt@google.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101115234937.580480400@google.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 19 10月, 2010 1 次提交
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由 Venkatesh Pallipadi 提交于
The idea was suggested by Peter Zijlstra here: http://marc.info/?l=linux-kernel&m=127476934517534&w=2 irq time is technically not available to the tasks running on the CPU. This patch removes irq time from CPU power piggybacking on sched_rt_avg_update(). Tested this by keeping CPU X busy with a network intensive task having 75% oa a single CPU irq processing (hard+soft) on a 4-way system. And start seven cycle soakers on the system. Without this change, there will be two tasks on each CPU. With this change, there is a single task on irq busy CPU X and remaining 7 tasks are spread around among other 3 CPUs. Signed-off-by: NVenkatesh Pallipadi <venki@google.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1286237003-12406-8-git-send-email-venki@google.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 12 3月, 2010 7 次提交
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由 Mike Galbraith 提交于
This features has been enabled for quite a while, after testing showed that easing preemption for light tasks was harmful to high priority threads. Remove the feature flag. Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301675.6785.44.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
Sync wakeups are critical functionality with a long history. Remove it, we don't need the branch or icache footprint. Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301817.6785.47.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
This feature never earned its keep, remove it. Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301591.6785.42.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
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: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301520.6785.40.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
This feature hasn't been enabled in a long time, remove effectively dead code. Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301447.6785.38.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
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: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301121.6785.30.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
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: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301062.6785.29.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 09 12月, 2009 1 次提交
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由 Peter Zijlstra 提交于
WAKEUP_RUNNING was an experiment, not sure why that ever ended up being merged... Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 17 9月, 2009 1 次提交
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由 Peter Zijlstra 提交于
Create a new wakeup preemption mode, preempt towards tasks that run shorter on avg. It sets next buddy to be sure we actually run the task we preempted for. Test results: root@twins:~# while :; do :; done & [1] 6537 root@twins:~# while :; do :; done & [2] 6538 root@twins:~# while :; do :; done & [3] 6539 root@twins:~# while :; do :; done & [4] 6540 root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 4750 usec Avg 497 usec Stdev 737 usec root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features root@twins:/home/peter# ./latt -c4 sleep 4 Entries: 48 (clients=4) Averages: ------------------------------ Max 14 usec Avg 5 usec Stdev 3 usec Disabled by default - needs more testing. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NIngo Molnar <mingo@elte.hu> LKML-Reference: <new-submission>
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- 16 9月, 2009 3 次提交
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由 Peter Zijlstra 提交于
We don't need to call update_shares() for each domain we iterate, just got the largets one. However, we should call it before wake_affine() as well, so that that can use up-to-date values too. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ingo Molnar 提交于
Add back FAIR_SLEEPERS and GENTLE_FAIR_SLEEPERS. FAIR_SLEEPERS is the old logic: credit sleepers with their sleep time. GENTLE_FAIR_SLEEPERS dampens this a bit: 50% of their sleep time gets credited. The hope here is to still give the benefits of fair-sleepers logic (quick wakeups, etc.) while not allow them to have 100% of their sleep time as if they were running. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Currently we use overlap to weaken the SYNC hint, but allow it to set the hint as well. echo NO_SYNC_WAKEUP > /debug/sched_features echo SYNC_MORE > /debug/sched_features preserves pipe-test behaviour without using the WF_SYNC hint. Worth playing with on more workloads... Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 15 9月, 2009 5 次提交
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由 Peter Zijlstra 提交于
I suspect a feed-back loop between cpuidle and the aperf/mperf cpu_power bits, where when we have idle C-states lower the ratio, which leads to lower cpu_power and then less load, which generates more idle time, etc.. Put in a knob to disable it. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
Make the idle balancer more agressive, to improve a x264 encoding workload provided by Jason Garrett-Glaser: NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 252.82 fps, 22096.60 kb/s encoded 600 frames, 250.69 fps, 22096.60 kb/s encoded 600 frames, 245.76 fps, 22096.60 kb/s NO_NEXT_BUDDY LB_BIAS encoded 600 frames, 344.44 fps, 22096.60 kb/s encoded 600 frames, 346.66 fps, 22096.60 kb/s encoded 600 frames, 352.59 fps, 22096.60 kb/s NO_NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 425.75 fps, 22096.60 kb/s encoded 600 frames, 425.45 fps, 22096.60 kb/s encoded 600 frames, 422.49 fps, 22096.60 kb/s Peter pointed out that this is better done via newidle_idx, not via LB_BIAS, newidle balancing should look for where there is load _now_, not where there was load 2 ticks ago. Worst-case latencies are improved as well as no buddies means less vruntime spread. (as per prior lkml discussions) This change improves kbuild-peak parallelism as well. Reported-by: NJason Garrett-Glaser <darkshikari@gmail.com> Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1253011667.9128.16.camel@marge.simson.net> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Add text... Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Mike Galbraith 提交于
Add a NEXT_BUDDY feature flag to aid in debugging. Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
It consists of two conditions, split them out in separate toggles so we can test them independently. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 11 9月, 2009 1 次提交
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由 Ingo Molnar 提交于
Nikos Chantziaras and Jens Axboe reported that turning off NEW_FAIR_SLEEPERS improves desktop interactivity visibly. Nikos described his experiences the following way: " With this setting, I can do "nice -n 19 make -j20" and still have a very smooth desktop and watch a movie at the same time. Various other annoyances (like the "logout/shutdown/restart" dialog of KDE not appearing at all until the background fade-out effect has finished) are also gone. So this seems to be the single most important setting that vastly improves desktop behavior, at least here. " Jens described it the following way, referring to a 10-seconds xmodmap scheduling delay he was trying to debug: " Then I tried switching NO_NEW_FAIR_SLEEPERS on, and then I get: Performance counter stats for 'xmodmap .xmodmap-carl': 9.009137 task-clock-msecs # 0.447 CPUs 18 context-switches # 0.002 M/sec 1 CPU-migrations # 0.000 M/sec 315 page-faults # 0.035 M/sec 0.020167093 seconds time elapsed Woot! " So disable it for now. In perf trace output i can see weird delta timestamps: cc1-9943 [001] 2802.059479616: sched_stat_wait: task: as:9944 wait: 2801938766276 [ns] That nsec field is not supposed to be that large. More digging is needed - but lets turn it off while the real bug is found. Reported-by: NNikos Chantziaras <realnc@arcor.de> Tested-by: NNikos Chantziaras <realnc@arcor.de> Reported-by: NJens Axboe <jens.axboe@oracle.com> Tested-by: NJens Axboe <jens.axboe@oracle.com> Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> LKML-Reference: <4AA93D34.8040500@arcor.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 15 1月, 2009 2 次提交
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由 Peter Zijlstra 提交于
Prefer tasks that wake other tasks to preempt quickly. This improves performance because more work is available sooner. The workload that prompted this patch was a kernel build over NFS4 (for some curious and not understood reason we had to revert commit: 18de9735 to make any progress at all) Without this patch a make -j8 bzImage (of x86-64 defconfig) would take 3m30-ish, with this patch we're down to 2m50-ish. psql-sysbench/mysql-sysbench show a slight improvement in peak performance as well, tbench and vmark seemed to not care. It is possible to improve upon the build time (to 2m20-ish) but that seriously destroys other benchmarks (just shows that there's more room for tinkering). Much thanks to Mike who put in a lot of effort to benchmark things and proved a worthy opponent with a competing patch. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
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: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 05 11月, 2008 1 次提交
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由 Peter Zijlstra 提交于
Impact: improve/change/fix wakeup-buddy scheduling Currently we only have a forward looking buddy, that is, we prefer to schedule to the task we last woke up, under the presumption that its going to consume the data we just produced, and therefore will have cache hot benefits. This allows co-waking producer/consumer task pairs to run ahead of the pack for a little while, keeping their cache warm. Without this, we would interleave all pairs, utterly trashing the cache. This patch introduces a backward looking buddy, that is, suppose that in the above scenario, the consumer preempts the producer before it can go to sleep, we will therefore miss the wakeup from consumer to producer (its already running, after all), breaking the cycle and reverting to the cache-trashing interleaved schedule pattern. The backward buddy will try to schedule back to the task that woke us up in case the forward buddy is not available, under the assumption that the last task will be the one with the most cache hot task around barring current. This will basically allow a task to continue after it got preempted. In order to avoid starvation, we allow either buddy to get wakeup_gran ahead of the pack. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NMike Galbraith <efault@gmx.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 20 10月, 2008 1 次提交
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由 Ingo Molnar 提交于
David Miller reported that hrtick update overhead has tripled the wakeup overhead on Sparc64. That is too much - disable the HRTICK feature for now by default, until a faster implementation is found. Reported-by: NDavid Miller <davem@davemloft.net> Acked-by: NPeter Zijlstra <peterz@infradead.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 22 9月, 2008 2 次提交
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由 Ingo Molnar 提交于
WAKEUP_OVERLAP is not a winner on a 16way box, running psql+sysbench: .27-rc7-NO_WAKEUP_OVERLAP .27-rc7-WAKEUP_OVERLAP ------------------------------------------------- 1: 694 811 +14.39% 2: 1454 1427 -1.86% 4: 3017 3070 +1.70% 8: 5694 5808 +1.96% 16: 10592 10612 +0.19% 32: 9693 9647 -0.48% 64: 8507 8262 -2.97% 128: 8402 7087 -18.55% 256: 8419 5124 -64.30% 512: 7990 3671 -117.62% ------------------------------------------------- SUM: 64466 55524 -16.11% ... so turn it off by default. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Lin Ming reported a 10% OLTP regression against 2.6.27-rc4. The difference seems to come from different preemption agressiveness, which affects the cache footprint of the workload and its effective cache trashing. Aggresively preempt a task if its avg overlap is very small, this should avoid the task going to sleep and find it still running when we schedule back to it - saving a wakeup. Reported-by: NLin Ming <ming.m.lin@intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 21 8月, 2008 1 次提交
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由 Peter Zijlstra 提交于
Yanmin reported a significant regression on his 16-core machine due to: commit 93b75217 Author: Peter Zijlstra <a.p.zijlstra@chello.nl> Date: Fri Jun 27 13:41:33 2008 +0200 Flip back to the old behaviour. Reported-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 27 6月, 2008 2 次提交
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由 Peter Zijlstra 提交于
Measurement shows that the difference between cgroup:/ and cgroup:/foo wake_affine() results is that the latter succeeds significantly more. Therefore bias the calculations towards failing the test. Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
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: NPeter Zijlstra <peterz@infradead.org> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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