Messages in this thread | | | Date | Wed, 8 Aug 2007 18:26:24 -0700 (PDT) | From | david@lang ... | Subject | Re: [PATCH 00/23] per device dirty throttling -v8 |
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On Thu, 9 Aug 2007, Greg Trounson wrote:
>> Measurements show that noatime helps 20-30% on regular desktop workloads, >> easily 50% for kernel builds and much more than that (in excess of 100%) >> for file-read-intense workloads. We cannot just walk past such a _huge_ >> performance impact so easily without even reacting to the performance >> arguments, and i'm happy Ubuntu picked up noatime,nodiratime and is >> whipping up the floor with Fedora on the desktop. >> > > Sorry I'm just not seeing those gains here. With my filesystems mounted with > atime defaults the Quake sources build in 1m28.856s. A test with ls -ltu > verifies that atime is working as expected. When I remount my filesystems > with: > mount [fs] -o remount,noatime,nodiratime > I get a compile time of 1m23.368s, a mere 6% improvement. > > This is on a dual-core Athlon 4200+ box running 2.6.21, so I would have > thought this to be close to a best-case file I/O test.
what sort of disks does this box have? and what filesystem? slower disks/filesystems can result in this showing a larger difference.
however 6% is a fairly significant gain.
David Lang - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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