Date: Sun, 13 Mar 2016 16:41:17 +0100 From: Fabian Keil <freebsd-listen@fabiankeil.de> To: Gary Jennejohn <gljennjohn@gmail.com> Cc: current@freebsd.org Subject: Re: how to recycle Inact memory more aggressively? Message-ID: <20160313164117.0301b79e@fabiankeil.de> In-Reply-To: <20160312093835.727d7197@ernst.home>
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[-- Attachment #1 --] Gary Jennejohn <gljennjohn@gmail.com> wrote: > In the course of the last year or so the behavior of the vm system > has changed in regard to how aggressively Inact memory is recycled. > > My box has 8GB of memory. At the moment I'm copying 100s of gigabytes > from one file system to another one. > > Looking at top I observe that there are about 6GB of Inact memory. > This value hardly changes. Instead of aggressively recycling the > Inact memory the vm now seems to prefer to swap. Are you using ZFS? > Last year, can't rmember excatly when, the behavior was totally > different. The vm very aggessively recycled Inact memory and, > even when copying 100s of GB of files, the system hardly swapped. > > It seems rather strange to me that the vm happily allows gigbytes > of Inact memory to be present and prefers swapping to recyclincg. > > Are there any sysctl's I can set to get the old behavior back? I don't think so. I'm currently using this patch set to work around the issue: https://www.fabiankeil.de/sourcecode/electrobsd/vm-limit-inactive-memory-more-aggressively.diff Patch 4 adds a couple of sysctls that can be used to let the ZFS ARC indirectly put pressure on the inactive memory until a given target is reached. Fabian [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAlblih0ACgkQBYqIVf93VJ2o/ACfX6vJ20dT/Je5Fr7DNmm6VAYU ZewAoIpW9cgiZxa5SG4cCgUrvw5tiXlc =ejF6 -----END PGP SIGNATURE-----home | help
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