> -----Original Message----- > From: Mike Galbraith [mailto:[EMAIL PROTECTED] > Sent: Wednesday, August 17, 2005 11:10 PM > At 09:43 PM 8/17/2005 -0600, you wrote: > > > > > > Have you tried sysrq t? See the Documentation/sysrq.txt file. > > > >This is a headless system. > > You could try netconsole.
Haven't heard of it before. Will look into it. But I doubt it will help pinpoint the semaphore holder, if all I can do is sysrq stuff. > > > > > > > How stuck is the system? > > > > > > Keith > > > >Very. Only pingable, but can't login via > telnet/ssh/anything. Reason is > >the same reason the low priority mystery task is unable to run and > >release the held semaphore. > > (hmm. I'm obviously missing some original context here) > > Sounds like there must be another player who is RT prio + spinning. > > -Mike Very good! Yes, I left out that piece of detail in my original posting. There is a real low priority (4) SCHED_FIFO (hence still higher than any SCHED_OTHER) task spinning. But it is not the semaphore holder. I am trying to identify which kernel thread (because that's most likely) running at SCHED_OTHER real low priority (too nice) is holding the semaphore, locking out a priority 50 SCHED_FIFO task in its sys_write() as a result. Thanks - Bhavesh Bhavesh P. Davda | Distinguished Member of Technical Staff | Avaya | 1300 West 120th Avenue | B3-B03 | Westminster, CO 80234 | U.S.A. | Voice/Fax: 303.538.4438 | [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
