On 16 March 2011 18:46, Roman Divacky <rdiva...@freebsd.org> wrote: > > On Wed, Mar 16, 2011 at 04:22:59PM +0000, Ivan Voras wrote: > > Author: ivoras > > Date: Wed Mar 16 16:22:59 2011 > > New Revision: 219699 > > URL: http://svn.freebsd.org/changeset/base/219699 > > > > Log: > > The hardware has caught up; improvements are now observed even at 128, > > but stay conservative and bump read_max to "only" 64 (it will probably be > > a good idea to increase this to 128 after the next major release). > > how did you measure this?
Specifically for this commit: my desktop 2xSATA 7200 RPM drives, gmirror, single read "dd" stream, bs=1m. (Are there any ready read multi-stream read tests which are not trivial i.e. they start from different positions in the file?) results: read_max=32 -> 78 MB/s read_max=64 -> 136 MB/s read_max=128 -> 141 MB/s I'm the one who previously bumped read_max from 8 to 32 about a year ago, based on tests under an (otherwise idle, naturally) VMWare cluster on a FC SAN, and a similar point of saturation was at read_max=64. Now it is at 128 with raw hardware. Maybe it should be tuned at 2^(major_freebsd_version-2) :) (as for safety & stability, I've put 2-3 new web servers in production this year with read_max=128 irregardless of this commit. It's stable). _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
