Messages in this thread | | | Subject | Re: possible lockdep regression introduced by 4d004099a668 ("lockdep: Fix lockdep recursion") | From | Filipe Manana <> | Date | Mon, 26 Oct 2020 11:59:29 +0000 |
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On 26/10/20 11:55, Jan Kara wrote: > On Mon 26-10-20 12:40:09, Peter Zijlstra wrote: >> On Mon, Oct 26, 2020 at 11:26:49AM +0000, Filipe Manana wrote: >>> Hello, >>> >>> I've recently started to hit a warning followed by tasks hanging after >>> attempts to freeze a filesystem. A git bisection pointed to the >>> following commit: >>> >>> commit 4d004099a668c41522242aa146a38cc4eb59cb1e >>> Author: Peter Zijlstra <peterz@infradead.org> >>> Date: Fri Oct 2 11:04:21 2020 +0200 >>> >>> lockdep: Fix lockdep recursion >>> >>> This happens very reliably when running all xfstests with lockdep >>> enabled, and the tested filesystem is btrfs (haven't tried other >>> filesystems, but it shouldn't matter). The warning and task hangs always >>> happen at either test generic/068 or test generic/390, and (oddly) >>> always have to run all tests for it to trigger, running those tests >>> individually on an infinite loop doesn't seem to trigger it (at least >>> for a couple hours). >>> >>> The warning triggered is at fs/super.c:__sb_start_write() which always >>> results later in several tasks hanging on a percpu rw_sem: >>> >>> https://pastebin.com/qnLvf94E >>> >>> What happens is percpu_rwsem_is_held() is apparently returning a false >>> positive, >> >> That smells like the same issue reported here: >> >> https://lkml.kernel.org/r/20201022111700.GZ2651@hirez.programming.kicks-ass.net >> >> Make sure you have commit: >> >> f8e48a3dca06 ("lockdep: Fix preemption WARN for spurious IRQ-enable") >> >> (in Linus' tree by now) and do you have CONFIG_DEBUG_PREEMPT enabled? > > Hum, I am at 5.10-rc1 now and above mentioned commit doesn't appear to be > there? Also googling for the title doesn't help...
Same here, can't find in Linus' tree neither through google.
> > Honza >
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