3 Jan
2003
3 Jan
'03
7:13 p.m.
[brief description of problem: jack + several other jack clients + disk
activity - a tar process, for example - hangs the machine]
This is what I'm currently testing:
2.4.20 + capabilities + preempt + lowlat +
[from Con Koliva's page]
Read latency2 disk hack (Andrew Morton) + ACPI + variable HZ (1000) +
[from an older jl patch]
drm low latency +
[from ext3 page]
ext3 patches for 2.4.20
I built the icebox kernel debugger to try to get some info on where the
program is hanging and this is what I get in terms of what's happening
(four instances of breaking into the debugger with the Sysrq-d key),
this is the list of tasks:
4) [other 3 erased for brevity]
schedule +1ab
sleep_on +45
bread +20
__mark_inode_dirty +d9
pipe_write +1b9
poll_freewait +44
sys_write +9f
system_call +33
So the system seems to be stuck in __mark_inode_dirty
I browsed the Kernel Source and there is only one mark_inode_dirty in
pipe_write (in fs/pipe.c). So we know where it is hanging...
And in __mark_inode_dirty (in fs/inode.c) there is one
spin_lock(&inode_lock)
call, and I guess that is where the whole thing is hanging. So something
is holding that lock... how do I find out who is doing that? Apparently
the handling of inode_lock is confined to inode.c. I'll keep reading.
Maybe the pipe in question is one of the pipes that jack uses for ipc?
-- Fernando