On Mon, May 10, 2010 at 12:45:45PM -0400, Martin Langhoff wrote: > On Mon, May 10, 2010 at 2:37 AM, James Cameron <[email protected]> wrote: > > I've no explanation for this behaviour. > > Do we still have some (sugar?) log files opened 'sync'? ext3/4 still > 'fsync' the whole partition, which may explain the erratic > performance.
No, no Sugar log files are opened O_SYNC at the moment. I fixed that. The test also reproduces without Sugar running, and also in single user mode. This excludes Sugar and all user-space, suggesting the problem is isolatable to or a combination of kernel, hardware and media. -- #!/bin/sh # test filesystem write echo 1 > /proc/sys/vm/drop_caches echo 2 > /proc/sys/vm/drop_caches echo 3 > /proc/sys/vm/drop_caches time strace -o /tmp/k -e write -T dd if=/dev/zero of=/root/file bs=8192 count=32000 time sync grep write /tmp/k|cut -f2 -d'<'|cut -f1 -d'>'|sort -rn|more -- James Cameron http://quozl.linux.org.au/ _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
