Hi Sanjoy,
I think this is definitely getting to the point where it looks like a
kernel problem. Could you report this to the Linux Kernel mailing list
and to the ext3 maintainers? (I could do it, but I can't reproduce the
problem so I would just be a useless middle man.)
Cheers,
Bart
Sanjoy Mahajan wrote:
In summary, I think I have a way to reproduce the problem. Next time
I'll try just the 'mount' command without unplugging the AC power.
I'm in the middle of that experiment. I rebooted at 7:20am and saw the
'locate' cron job start at 7:30. A few minutes later, at 7:35:11, I ran
the following mount command while leaving the AC power plugged in (and
leaving the laptop-mode settings unchanged, so I didn't turn off laptop
mode). Here is the command (in bash):
time mount /dev/sda2 -t ext3 / -o remount,rw,errors=remount-ro,commit=600
It is still running at 9.00am! The system is sluggish, and is
especially sluggish with anything requiring disk I/O, like saving or
loading new files in Emacs.
Here are the first two lines of the 'top' output (at 9:10):
4637 root 20 0 3260 756 644 R 106 0.0 93:39.75 mount
4509 nobody 39 19 6916 4680 908 R 96 0.3 67:10.69 find
One guess is that the mount keeps waiting for the 'find' to do something
or other, but the 'find' never gets a chance because its ionice priority
is too low:
$ ionice -p 4509
idle
I just (9:05am) did
ionice -p4509 -c2 -n0
but it hasn't helped yet (the 'mount' is still running strong).
'top' claims that all the CPU time is system time, on both cores. The
'find' process is probably in system time with all its 'stat' calls.
But 'strace -p 4637' (the 'mount' process) produces no output, so I
cannot figure out what system calls are taking up so much system time.
And the 'strace' is not interruptable with ^C. It needed to be stopped
with ^Z and the 'kill -9 %1' to get rid of it (which I just did).
I just tried to kill the 'mount' process. Neither ^C, 'kill', nor 'kill
-9' worked. I'm going to reboot now as it's almost two hours now and
the CPU is very hot (92 C).
-Sanjoy
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
