On Wed, May 16, 2007 at 12:33:42PM -0700, Andrew Morton wrote: > On Wed, 16 May 2007 15:13:39 -0400 > Chris Mason <[EMAIL PROTECTED]> wrote: > > > > > > > If that's still working then the problem will _probably_ be directory > > > writeout. Possibly inodes, but they should be well-laid-out. > > > > > > Were you using dir_index? That might be screwing things up. > > > > Yes, dir_index. A quick test of mkfs.ext3 -O ^dir_index seems to still > > have the problem. Even though the inodes are well laid out, is the > > order they get written sane? > > Should be: it uses first-fit. > > > Looks like ext3 is just walking a list of > > bh/jh, maybe we can just sort the silly thing? > > The IO scheduler is supposed to do that. > > But I don't know what's causing this.
I had high hopes of blaming cfq, but deadline gives the same results: create dir kernel-0 222MB in 5.38 seconds (41.33 MB/s) ... [ ~30MB/s here ] ... create dir kernel-7 222MB in 8.11 seconds (27.42 MB/s) create dir kernel-8 222MB in 18.39 seconds (12.09 MB/s) create dir kernel-9 222MB in 6.91 seconds (32.18 MB/s) create dir kernel-10 222MB in 24.32 seconds (9.14 MB/s) create dir kernel-11 222MB in 12.06 seconds (18.44 MB/s) create dir kernel-12 222MB in 10.95 seconds (20.31 MB/s) The good news is that if you let it run long enough, the times stabilize. The bad news is: create dir kernel-86 222MB in 15.85 seconds (14.03 MB/s) create dir kernel-87 222MB in 28.67 seconds (7.76 MB/s) create dir kernel-88 222MB in 18.12 seconds (12.27 MB/s) create dir kernel-89 222MB in 19.77 seconds (11.25 MB/s) echo 2048 > /sys/block/..../nr_requests didn't do it either. I guess I'll have systemtap tell me more about the log flushing. -chris - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
