Messages in this thread | | | From | Byungchul Park <> | Subject | Re: [PATCH RFC v7 08/23] dept: Apply sdt_might_sleep_strong() to PG_{locked,writeback} wait | Date | Sat, 21 Jan 2023 12:35:09 +0900 |
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Byungchul wrote: > Hillf wrote: > > On 9 Jan 2023 12:33:36 +0900 Byungchul Park <byungchul.park@lge.com> > > > Makes Dept able to track dependencies by PG_{locked,writeback} waits. > > > > > > Signed-off-by: Byungchul Park <byungchul.park@lge.com> > > > --- > > > > Hey Byungchul > > +cc max.byungchul.park@gmail.com > > Hi, > > This email never reached to me. > > > Is DEPT able to get deadlock reported for the syzbot report [1]? > > DEPT can detect the case 100% *IF* the folio_trylock() is released > within the same context since DEPT tracks folio_trylock(), folio_lock() > and folio_unlock(), and it's definitely a deadlock. > > But as we know, because folio_trylock() can be released by another > context like irq, it might be either just a severe slowdown of the > context triggering folio_unlock() or a literal deadlock where the > context is involved. I dunno which one is the case. > > In short, DEPT can detect this case too *IF* it's a literal deadlock, > but it doesn't if it's just a slowdown. I'm planning to warn it even if > there is a slowdown tho, not for now. > > Let me reproduce the following issue. I will share the result.
Hi Hillf,
Can we talk about the DEPT report for the hang issue in here?
https://lore.kernel.org/lkml/1673235231-30302-1-git-send-email-byungchul.park@lge.com/T/#m458f4d5f3da06a28c7fbb39b392d05e4c016603b
Thanks, Byungchul
> > Hillf > > > > [1] https://lore.kernel.org/lkml/6383cde5-cf4b-facf-6e07-1378a485657d@I-love.SAKURA.ne.jp/ > > Byungchul >
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