Martin,
can you explain what local_irq_disable() in do_request in
drivers/ide/ide.c should guard against? There is dozen (all unless I
missed something) of paths which do not local_irq_enable(), and neither
does the caller...
And what you meant with (endless) loop in ide_do_request?
And where do_request() callers obtain channel lock so that do_request()
can release and reacquire it?
My problem is that fsck reliable dies between 79.6 and 81% of its
run - on UP machine with SMP kernel:
NMI detected lockup on CPU0 ...
Stack trace: do_request + 315/924
do_ide_request
generic_unplug_device
blk_run_queues
do_page_cache_readahead
page_cache_readahead
do_generic_file_read
generic_file_read
file_read_actor
vfs_read
sys_read
do_request+315 is clear_bit(IDE_BUSY, channel->active) at line 606.
The do_ide_request()'s loop
while (!test_and_set_bit(IDE_BUSY, ch->active)) {
do_request(ch)
}
looks very suspicious to me - it will loop here until the end of world,
as there is nothing in queue, so do_request() will always exit
with IDE_BUSY cleared.
Next question is: with this stack trace, where you obtained ch->lock,
so that do_request() can do call to spin_unlock(ch->lock) ? It looks
to me like that I should get 'unlocking unlocked spinlock' with
appropriate debug.
What (probably) happened is that hardware finished request before
spin_lock_irq(ch->lock) (at line 749) was executed, we quit with
IDE_BUSY cleared, and it was last thing we did... Maybe I should
go back to IDE-98?
Thanks,
Petr Vandrovec
vandrove@vc.cvut.cz
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This archive was generated by hypermail 2b29 : Tue Jul 30 2002 - 14:00:21 EST