Date: Thu, 14 Dec 2017 05:52:15 +1100 From: Peter Jeremy <peter@rulingia.com> To: Baptiste Daroussin <bapt@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: Re: svn commit: r326619 - stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <20171213185214.GA12026@server.rulingia.com> In-Reply-To: <201712061001.vB6A12Ot032201@repo.freebsd.org> References: <201712061001.vB6A12Ot032201@repo.freebsd.org>
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--wac7ysb48OaltWcw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2017-Dec-06 10:01:02 +0000, Baptiste Daroussin <bapt@FreeBSD.org> wrote: >Author: bapt >Date: Wed Dec 6 10:01:02 2017 >New Revision: 326619 >URL: https://svnweb.freebsd.org/changeset/base/326619 > >Log: > MFC r325851: > =20 > remove the poor emulation of the IllumOS needfree global variable to pre= vent > the ARC reclaim thread running longer than needed. > =20 This change appears to break the backpressure mechanism that forces ARC to release wired memory. Running FreeBSD/amd64 r326743, I found that my system was thrashing badly with almost all memory (~31GB out of 32GB) wired (including 19GB ARC, 7GB VBox guests). Running a tool that just allocates and dirties a large amount of memory had no effect on the ARC size. Reverting this change only restores normal behaviour where ARC will shrink under pressure. My ZFS boot tunables are: vfs.zfs.arc_max=3D"24G" vfs.zfs.arc_meta_limit=3D"12G" --=20 Peter Jeremy --wac7ysb48OaltWcw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQJ8BAEBCgBmBQJaMXbeXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXRFRUIyOTg2QzMwNjcxRTc0RTY1QzIyN0Ux NkE1OTdBMEU0QTIwQjM0AAoJEBall6Dkogs0qBEP/jgEyTai46NhxOuUzzxI6y2g rwnxgAAX+yMOU4ZdaK0SuSQUsmCS1SHQnuORG1Ay1CCaWcf6vtKEt0Ce90+zTMjZ qqmWLvBOOCfBSCTQzcVs1ICcKtML/zsXEO2wxyZu94yIc4kwa5Az4R5J5RCeCb9w 1iGSFWbeyTevC0QReKgj2NKhVZ6Lb9281GXq3aZJH1cONG1xDCOb9V8kw9VRtj/G sy5gaUK8ph+BWySd/PJ02cibJBPUptHSBUQdJGnU2h7HLuy/dO0tFrb2WmDozsFE CXeuPtdE8bOlJVEMFj7w1KYPIXjKBUP6g+y1ZI7hFWrecbwLWVWCiO0AmB5/bZTT +D79/c7DxLMIXwjN8iaRwJiAfMeFJcZQFVu7RtKHHb9gEpAU5QRt57RjJtqTuhXn 5tC5M1DDv5lwz6cACFG7dlRfaLvAcJgfhG0hJKtWlFlSUSfpX/Mlcv2gJUWZz/4t K/wE1iRX+EvRkmFnBThJtzizyu1NIyT+CZu4PbwiL6WJdesoO3f+vfcBnQaDR2gL /bHSofISm/GKhpCbzmbaZ7Xw1Fp/S6TBthKBESYFTExKze4Am6EdayqphIa9Sytj J9euCfAxags1d3IJ30GF7pNzqYBgXmobd4Wfca1F8P1ZQRtPtqHg6wb1kIOKYyAm rTQkYjlzaOmbjMrz0H4Y =fypZ -----END PGP SIGNATURE----- --wac7ysb48OaltWcw--
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