Enable low priority thread pool on Linux
Categories
(Core :: Graphics: WebRender, task, P3)
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()
People
(Reporter: bpeers, Assigned: bpeers)
References
Details
Attachments
(1 file, 1 obsolete file)
The code was submitted; enable it by default so we can see Talos numbers for the combined result.
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Updated•1 year ago
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Comment 1•1 year ago
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Pushed by bpeers@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/d39132658a17 Enable low priority thread pool on Linux r=jrmuizel
Comment 3•1 year ago
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bugherder |
Comment 4•1 year ago
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Updated•1 year ago
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Backout by aiakab@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/a8197fa66cfd Backed out changeset d39132658a17 as requested by Bert Peers for causing regressions.
Updated•1 year ago
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Assignee | ||
Comment 6•1 year ago
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At least on Windows, if I look at the affinity of everything else, then I don't see anything that's also insisting on being on core 0..7. So in theory the work that's causing ~3% slowdown could migrate to other cores and shouldn't hurt perf. So I'm still not sure what happened there. (Edit: perhaps >8 cores for Talos, and affinity prevents the pool from spreading out, causing -3% due to hyperthreading?)
As for the extra 15% slowdown when actually enabling the low priority pool... If that's really Linux saying "oh you wanted SCHED_BATCH threads, no problem" and they get 15% less CPU time, then... it's working great, I guess :) One option would be to semi-cheat and disable the pool on Talos: if Talos tests are for detecting regressions in raw SVG rasterization speed, then the throughput-for-latency trade-off is irrelevant there. Another option is to put the "low priority" pool back to normal priority, and instead boost the "normal" pool to higher-than-normal. In theory, with nothing running on the higher priority pool, that should keep perf level at +- minus 3% from affinity.
(Reminder that all of this is just a temporary workaround until we have a unified scheduler and/or yieldable SVG tasks.)
There's a r+ patch which didn't land and no activity in this bug for 2 weeks.
:bpeers, could you have a look please?
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Comment 8•1 year ago
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Invalid, no longer using low priority threads.
Description
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