On 2 October 2010 18:52, Ted Ts'o <tytso@xxxxxxx> wrote: > On Sun, Sep 26, 2010 at 10:04:13PM +0200, Rafael J. Wysocki wrote: >> >> Bug-Entry   : http://bugzilla.kernel.org/show_bug.cgi?id=17361 >> Subject        : Watchdog detected hard LOCKUP in jbd2_journal_get_write_access >> Submitter   : Christian Casteyde <casteyde.christian@xxxxxxx> >> Date     Â: 2010-08-29 19:59 (29 days old) > > See my latest comment here: > >  Âhttps://bugzilla.kernel.org/show_bug.cgi?id=17361#c14 > > This subject line is highly misleading, since after -rc4, the stack > traces are in places all over the kernel, in other places other than > ext4/jbd2. ÂSo I fear no one is looking at this bug report given the > highly misleading subject line. > > It looks like you have spinlock debugging, and yet there wan't any > spinlocks listed on the initial ext4 might_sleep() warning. ÂSo > something looks highly confused. > > The fact that you closed other bugs as duplicates of this one that > relate to kmemcheck makes me wonder if this is really a kmemcheck bug. > (If so, the subject line here is doubly, doubly misleading.) > > Do you see any symptoms if you turn off kmemcheck? ÂAre you sure this > isn't just only a kmemcheck bug? I just had a quick glance at the report, and here's my gut feeling: I see perf symbols in the stack trace. I don't think kmemcheck and perf play nicely together (for example if perf uses NMIs to write data to its buffers, it could get a page fault inside the NMI handler, which is not so nice, I think). Isn't this exactly what Frederic Weisbecker tried to detect and warn about in a patch that I saw recently? Please do as Ted suggested and try to turn kmemcheck off. Vegard -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
