Messages in this thread |  | | Subject | Re: [PATCH v2] locking/hung_task: Show all hung tasks before panic | From | Tetsuo Handa <> | Date | Sun, 8 Apr 2018 01:24:24 +0900 |
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Dmitry Vyukov wrote: > On Sat, Apr 7, 2018 at 5:39 PM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Sat, Apr 07, 2018 at 09:31:19PM +0900, Tetsuo Handa wrote: > >> are for replacing debug_show_all_locks() in check_hung_task() for cases like > >> https://syzkaller.appspot.com/bug?id=26aa22915f5e3b7ca2cfca76a939f12c25d624db > >> because we are interested in only threads holding locks. > >> > >> SysRq-t is too much but SysRq-w is useless for killable/interruptible threads... > > > > Or use a script to process the sysrq-t output? I mean, we can add all > > sorts, but where does it end?
Maybe allow khungtaskd to call call_usermode_helper() to run arbitrary operations instead of just calling panic()?
> > Good question. > We are talking about few dozen more stacks, right? > > Not all kernel bugs are well reproducible, so it's not always possible > to go back and hit sysrq-t. And this come up in the context of syzbot, > which is an automated system. It reported a bunch of hangs and most of > them are real bugs, but not all of them are easily actionable. > Can it be a config or a command line argument, which will make syzbot > capture more useful context for each such hang? >
It will be nice if syzbot testing is done with kdump configured, and the result of automated scripting on vmcore (such as "foreach bt -s -l") is available.
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