On Fri, 2016-01-22 at 21:49 +0100, Premysl Kouril wrote: > On 22 Jan 2016 17:43, "James Bottomley" < > james.bottom...@hansenpartnership.com> wrote: > > The 3x difference in the benchmarks would seem to indicate a local > > tuning or configuration problem, because it's not what most people > > see. What the current benchmarks seem to show is about a 1-5% > > difference between the directio and the direct to block paths > > depending on fstype, how its tuned, ioscheduler and underlying > > device. > > I will try to find problem in our configuration and re-run our > benchmarks. By chance do you have some more information (and possibly > configuration) about the bechmarks you are mentioning?
Well, what I'd actually do (and don't say I put you up to this) is send an email to linux-fsde...@vger.kernel.org alleging a 60% performance drop on O_DIRECT under whatever filesystem it is, along with the figures you publish. I bet this will get a swift response from the lead developer for that filesystem and a demand to help you tune your system better ... James __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
