Public bug reported: On a fresh lucid install, an unmount of an empty tmpfs mount is quite slow:
# mkdir -p /tmp/test; mount -t tmpfs nodev /tmp/test; time umount /tmp/test real 0m0.318s user 0m0.000s sys 0m0.020s If there is pending I/O on any other filesystem, it can be even slower: # dd if=/dev/zero of=/tmp/testfile bs=1024 count=1024 # mkdir -p /tmp/test; mount -t tmpfs nodev /tmp/test; time umount /tmp/test real 0m8.270s user 0m0.000s sys 0m0.010s This is a regression from previous versions, e.g. on hardy: # uname -r 2.6.24-19-generic # mkdir -p /tmp/test; mount -t tmpfs nodev /tmp/test; time umount /tmp/test real 0m0.001s user 0m0.000s sys 0m0.000s The root cause is the workaround patch which fixed bug https://bugs.launchpad.net/ubuntu/+source/linux/+bug/543617. It syncs all filesystems when umount is called, not just the involved filesystem, and applies to unmount of non-ext4 FSs. I've verified that the problem goes away with that patch reverted. ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: regression-release -- tmpfs umount slowdown https://bugs.launchpad.net/bugs/585092 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
