HAMMER update 23-Feb-2008

Matthew Dillon dillon at apollo.backplane.com
Sun Feb 24 11:50:04 PST 2008

:I've been playing with it, and while it works nice when working on a small
:amount of files, it often locks up(ctrl+T or ctrl+C won't work) during
:a task like this (I've made sure that this has no problem writing on a UFS
:# cpdup /usr/pkgsrc/. /mnt/HAMMER/.
:I added a few kprintf()'s around tsleep()'s and wakeup()'s in
:hammer_subs.c, and I found that it is often the case that it locked up,
:tsleep() won't return (because I didn't see the kprintf() message after it)
:after being woken up by hammer_lock_downgrade().  ctrl+alt+esc mostly
:works, but it takes very long time to drop into DDB once it locked up.

    I think I have reproduced this on my test box, but not in a vkernel yet.
    It seems to be triggered fairly reliably if I do the cpdup above in
    one xterm, and try to ls -lR the target mount in another xterm.

    I wasn't able to break into DDB, though.  It looks like a hard loop
    somewhere.  Is that what you are seeing?  Some sort of hard loop in
    the kernel?

					Matthew Dillon 
					<dillon at backplane.com>

More information about the Kernel mailing list