On 26/07/2015 23:27, Scott Long wrote: > >> On Jun 12, 2015, at 4:01 AM, Andriy Gapon <a...@freebsd.org> wrote: >> >> Author: avg >> Date: Fri Jun 12 10:01:24 2015 >> New Revision: 284297 >> URL: https://svnweb.freebsd.org/changeset/base/284297 >> >> Log: >> several lockstat improvements >> >> 0. For spin events report time spent spinning, not a loop count. >> While loop count is much easier and cheaper to obtain it is hard >> to reason about the reported numbers, espcially for adaptive locks >> where both spinning and sleeping can happen. >> So, it's better to compare apples and apples. >> > > This causes spinning to be exceptionally more expensive just by having > KDTRACE_HOOKS enabled, whether or not Dtrace is actually in use. It > makes it undesirable to deploy with Dtrace by default since it impacts > performance. Is there a way to make the expensive collection optional, > or only enable when dtrace is using the lockstat module? Also have you > seen the other recent performance complaint related to this commit?
Sorry for the trouble. Commit https://svnweb.freebsd.org/changeset/base/285704 should have fixed the problem. Could you please check if that's so? Thanks. -- Andriy Gapon _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
