On Fri, 2008-05-30 at 17:50 +0200, Valerie Clement wrote: > Hi all, > Hi Valerie, > Since a couple of weeks, I did batches of tests to have some performance > numbers for the new ext4 features like uninit_groups, flex_bg or > journal_checksum on a 5TB filesystem. > I tried to test allmost all combinations of mkfs and mount options, but > I put only a subset of them in the result tables, the most significant > for me. > Thanks, that's very helpful. > I had started to do these tests on a kernel 2.6.26-rc1, but I'd got several > hangs and crashes occuring randomly outside ext4, sometimes in the slab > code or in the scsi driver eg., and which were not reproductible. > Since 2.6.26-rc2, no crash or hang occur with ext4 on my system. > > The first results and the test description are available here: > http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html Interesting nomballoc is faster than default (with mballoc) about 3%, but the fragmentation is much better. > http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html > > I will complete them in the next days. > > In the first batch of tests, I compare the I/O throughput to create > 1-GB files on disk in different configurations. The CPU usage is also > given to show mainly how the delayed allocation feature reduces it. > The average number of extents per file shows the impact of the > multiblock allocator and the flex_bg grouping on the file fragmentation. > At last, the fsck time shows how the uninit_groups feature reduces the > e2fsck duration. > Don't know if Jose has any suggestions, I am curious what's the impact of flex bg alone on fsck perf? > In the second batch of tests, the results show improvements in transactions > -per-second throughput when doing small files writes, reads and creates > when using the flex_bg grouping. > The same ffsb test on an XFS filesystem hangs, I will try to have traces. > > If you are interested in other tests, please let me know. > I also wondering if you get a chance to test larger inode (>256 bytes) with uninit group and flex bg? > Valérie > > > -- > 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 -- 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
