Date: Fri, 17 Feb 2012 14:54:51 +0100 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-fs@freebsd.org Subject: Re: ZFS and mem management Message-ID: <jhlm7b$tge$1@dough.gmane.org> In-Reply-To: <C82EC982-C587-4579-8DD7-01B97186E2D2@free.de> References: <15861.1329298812.1414986334451204096@ffe12.ukr.net> <92617.1329301696.6338962447434776576@ffe5.ukr.net> <CA%2BdUSyqKoqrfD_cgsfupsuZRE0O6dH-4F1roLp_GFaeBKJkN-w@mail.gmail.com> <CA%2BdUSyoRyC5O4D8tQQ9iDH2E87P3cxW_Ay8b6FuvzzbORpSYhA@mail.gmail.com> <96280.1329309582.18313701080496209920@ffe5.ukr.net> <jhgdsu$k7l$1@dough.gmane.org> <C82EC982-C587-4579-8DD7-01B97186E2D2@free.de>
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[-- Attachment #1 --] On 15/02/2012 17:07, Kai Gallasch wrote: > > Am 15.02.2012 um 15:02 schrieb Ivan Voras: > >> On 15/02/2012 13:39, Pavlo wrote: >>> >>> >>> >>> Unfortunately we can't afford disabling prefetch. It is too much of an >>> overhead. >>> >>> Also I made some tests. I have process that maps file using mmap() and >>> writes or reads first byte of each page of mapped file with some data. >> >> Note that ZFS is designed so that it interacts somewhat badly with >> mmap() and other kernel services which rely on coherency between VM and >> IO such as sendfile(). At the very best, you will have two in-kernel >> copies of all data buffers used with such interfaces, but there have >> been sporadic reports that there are other bugs with it. > > So best practice for running apache2 on FreeBSD ZFS is making sure EnableMMAP and EnableSendfile are disabled in httpd.conf, right? Yes. > (both are turned off by default) No, they are enabled by default: http://httpd.apache.org/docs/2.2/mod/core.html#enablemmap [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk8+XCsACgkQldnAQVacBcjQswCgjdhwr+oUhMCpbOwlxcG0K+uc e/oAoJJnKr2KTTfqKl/AwhFlQdql3Kkz =jmua -----END PGP SIGNATURE-----home | help
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