Messages in this thread | | | Date | Wed, 28 Jul 2010 19:57:16 -0400 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH] cfq-iosched: IOPS mode for group scheduling and new group_idle tunable |
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On Wed, Jul 28, 2010 at 04:22:12PM -0400, Vivek Goyal wrote: > I also did "time firefox &" testing to see how long firefox takes to > launch when linus torture test is running and without patch it took > around 20 seconds and with patch it took around 17 seconds. > > So to me above test results suggest that this patch does not worsen > the performance. In fact it helps. (at least on ext3 file system.) > > Not sure why are you seeing different results with XFS.
So why didn't you test it with XFS to verify his results? We all know that different filesystems have different I/O patters, and we have a history of really nasty regressions in one filesystem by good meaning changes to the I/O scheduler.
ext3 in fact is a particularly bad test case as it not only doesn't have I/O barriers enabled, but also has particularly bad I/O patterns compared to modern filesystems.
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