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Differential D49349

uma: Avoid excessive per-CPU draining
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Authored by des on Fri, Mar 14, 12:56 AM.
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F112540193: D49349.diff
Wed, Mar 19, 2:04 PM
F112483933: D49349.id152240.diff
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F112483206: D49349.id152356.diff
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kevans
siderop1_netapp.com

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kib
gallatin
siderop1_netapp.com
markj
Commits
rGf506d5af50fc: uma: Avoid excessive per-CPU draining
Summary

After commit 389a3fa693ef, uma_reclaim_domain(UMA_RECLAIM_DRAIN_CPU)
calls uma_zone_reclaim_domain(UMA_RECLAIM_DRAIN_CPU) twice on each zone
in addition to globally draining per-CPU caches. This was unintended
and is unnecessarily slow; in particular, draining per-CPU caches
requires binding to each CPU.

Stop draining per-CPU caches when visiting each zone, just do it once in
pcpu_cache_drain_safe() to minimize the amount of expensive sched_bind()
calls.

Fixes: 389a3fa693ef ("uma: Add UMA_ZONE_UNMANAGED")

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rG FreeBSD src repository
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Event Timeline

markj created this revision.Fri, Mar 14, 12:56 AM
Herald added a subscriber: imp. · View Herald TranscriptFri, Mar 14, 12:56 AM
markj requested review of this revision.Fri, Mar 14, 12:56 AM
Harbormaster completed remote builds in B62910: Diff 152240.Fri, Mar 14, 12:56 AM
des accepted this revision.Fri, Mar 14, 9:03 AM
This revision is now accepted and ready to land.Fri, Mar 14, 9:03 AM
siderop1_netapp.com added a subscriber: siderop1_netapp.com.Fri, Mar 14, 1:23 PM
kib accepted this revision.Fri, Mar 14, 2:37 PM
gallatin accepted this revision.Fri, Mar 14, 5:38 PM
siderop1_netapp.com accepted this revision.Fri, Mar 14, 9:21 PM

FWIW, internal testing with an equivalent diff shows the intermittent (~8%) OOM panics seen with 389a3fa693ef are now resolved. Thanks!

kevans added a subscriber: kevans.Sat, Mar 15, 4:43 AM
des commandeered this revision.Mon, Mar 17, 7:12 PM
des edited reviewers, added: markj; removed: des.

commandeering since @markj is afk

Closed by commit rGf506d5af50fc: uma: Avoid excessive per-CPU draining (authored by markj, committed by des). · Explain WhyMon, Mar 17, 7:14 PM
This revision was automatically updated to reflect the committed changes.
des added a commit: rGf506d5af50fc: uma: Avoid excessive per-CPU draining.

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PathSize
sys/
vm/
7 lines

Diff 152356

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sys/vm/uma_core.c

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