Date: Thu, 29 Aug 2013 12:17:50 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-stable@freebsd.org Subject: Re: Suggest changing dirhash defaults for FreeBSD 9.2. Message-ID: <kvn747$j7e$1@ger.gmane.org> In-Reply-To: <F4E60E862AF142AFBA86521E79C0BCAA@white> References: <521C9E85.4060801@UToledo.edu> <CAE-mSOLCYRM0LRLRgmaEZN1u5ozttJZC3kWtw3Zarqik1N29zw@mail.gmail.com> <521D7552.5080008@UToledo.edu> <kvkh1j$7fj$1@ger.gmane.org> <F4E60E862AF142AFBA86521E79C0BCAA@white>
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[-- Attachment #1 --] On 29/08/2013 03:32, Dewayne Geraghty wrote: > From the analysis perforned in 2009, and referenced earlier by Robert, this > https://wiki.freebsd.org/DirhashDynamicMemory and other material at this site, > indicates that the reclaimage interval is workload dependent and that 5 to 8 seconds seems, on average, to be adequate. I'm having trouble understanding what the graphs are saying - you seem to have almost consistently worse results with increasing dirhash memory and/or reclaim age. > Is the discussion, rather than (synthetic) workload > performance, sufficient to warrant changing the default settings by a factor of 12? Yes, and also for an additional reason on top of what I've already said in @fs and @hackers: it will be at least 10 years before someone remembers to bumb this tunable again, so I consider a little overkill to be ok. [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlIfH88ACgkQ/QjVBj3/HSzBjwCfcys0NTVXWJEcgy1Oxw0vR2iW 8zEAoI3mw2cZ5rHzMZ+rQ2RlNNR580CY =/TYO -----END PGP SIGNATURE-----
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