Reduce ARC fragmentaion threshold
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Authored by smh on Mar 15 2017, 12:40 PM.

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mav
avg

Commits

rS315449: Reduce ARC fragmentation threshold

Summary

As ZFS can request up to SPA_MAXBLOCKSIZE memory block e.g. during zfs recv, update the threshold at which we start agressive reclamation to use SPA_MAXBLOCKSIZE (16M) instead of the lower zfs_max_recordsize which defaults to 1M.

This was reported here:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194513

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Build Status

Buildable 8058
Build 8250: CI src build	Jenkins
Build 8249: arc lint + arc unit

Event Timeline

smh created this revision.Mar 15 2017, 12:40 PM

Herald added subscribers: delphij, imp. · View Herald TranscriptMar 15 2017, 12:40 PM

smh added a reviewer: mav.Mar 15 2017, 12:40 PM

I have no objections. It may be too aggressive if fragmentation was somehow caused not by ZFS, but any way I don't know any other place in system which would bother to do this, while I know other places that suffer quietly from fragmentation.

This revision is now accepted and ready to land.Mar 15 2017, 12:45 PM

Harbormaster completed remote builds in B8058: Diff 26273.Mar 15 2017, 1:15 PM

smh added a reviewer: avg.Mar 17 2017, 12:14 PM

avg accepted this revision.Mar 17 2017, 12:22 PM

Closed by commit rS315449: Reduce ARC fragmentation threshold (authored by smh). · Explain WhyMar 17 2017, 12:35 PM

This revision was automatically updated to reflect the committed changes.