* Linus Torvalds <torva...@linux-foundation.org> wrote: > On Tue, 6 Jan 2009, Linus Torvalds wrote: > > > > Right now, if some process deadlocks on a mutex, we get hung process, > > but with a nice backtrace and hopefully other things (that don't need > > that lock) still continue to work. > > Clarification: the "nice backtrace" we only get with something like > sysrq-W, of course. We don't get a backtrace _automatically_, but with > an otherwise live machine, there's a better chance that people do get > wchan or other info. IOW, it's at least a fairly debuggable situation.
btw., the softlockup watchdog detects non-progressing uninterruptible tasks (regardless of whether they locked up due to mutexes or any other reason). This does occasionally help in debugging deadlocks: http://marc.info/?l=linux-mm&m=122889587725061&w=2 but it would indeed be also good to have the most common self-deadlock case checked unconditionally in the mutex slowpath. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
