On Mon, 28 Jul 2008 13:34:12 +0900 Hisashi Hifumi <hifumi.hisashi@xxxxxxxxxxxxx> wrote: > Hi > > >> > > >> > Are there significant numbers of people using block size < page size in > >> > situations where performance is important and significantly improved by > >> > this patch? Can you give any performance numbers to illustrate perhaps? > >> > >> With XFS lots of people use 4k blocksize filesystems on ia64 systems > >> with 16k pages, so an optimization like this would be useful. > > > >As Nick says, we really should have some measurement results which > >confirm this theory. Maybe we did do some but they didn't find theor > >way into the changelog. > > > >I've put the patch on hold until this confirmation data is available. > > > > I've got some performance number. > I wrote a benchmark program and got result number with this program. > This benchmark do: > 1, mount and open a test file. > 2, create a 512MB file. > 3, close a file and umount. > 4, mount and again open a test file. > 5, pwrite randomly 300000 times on a test file. offset is aligned by IO size(1024bytes). > 6, measure time of preading randomly 100000 times on a test file. > > The result was: > 2.6.26 > 330 sec > > 2.6.26-patched > 226 sec > > Arch:i386 > Filesystem:ext3 > Blocksize:1024 bytes > Memory: 1GB > > On ext3/4, a file is written through buffer/block. So random read/write mixed workloads > or random read after random write workloads are optimized with this patch under > pagesize != blocksize environment. This test result showed this. OK, thanks. Those are pretty nice numbers for what is probably a fairly common workload. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
