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* blk-mq hangs easily with LLVM+clang test suite
@ 2018-01-21 16:19 David Zarzycki
  2018-01-21 17:17 ` Bart Van Assche
  0 siblings, 1 reply; 6+ messages in thread
From: David Zarzycki @ 2018-01-21 16:19 UTC (permalink / raw)
  To: linux-block

Hello,

I think I=E2=80=99ve narrowed down a kernel hang to the multi-queue =
block layer when running the LLVM+clang test suite. Here is what I=E2=80=99=
ve gathered:

1) The hang does *not* reproduce on tmpfs or a SATA SSD drive.
2) The hang does reproduce on blk-mq devices (NVMe or loopback to a file =
in tmpfs).
3) The hang does reproduce with ext4 or xfs, so the filesystem doesn=E2=80=
=99t seem to matter.

How can I help debug this further?

Thanks,
Dave

For reference, reproduction steps:

cd /to/a/blk-mq/partition
git clone https://git.llvm.org/git/llvm.git
cd llvm/tools
git clone https://git.llvm.org/git/clang.git
cd ..
mkdir t
cd t
cmake -G Ninja \
	-DCMAKE_BUILD_TYPE=3DRelease \
	-DLLVM_ENABLE_ASSERTIONS=3DTRUE \
	-DLLVM_TARGETS_TO_BUILD=3DX86 ..
# It only takes a few runs of the test suite on a 48-core system
while true
do
	ninja check-all
done=

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-01-22 17:40 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-01-21 16:19 blk-mq hangs easily with LLVM+clang test suite David Zarzycki
2018-01-21 17:17 ` Bart Van Assche
2018-01-21 17:39   ` David Zarzycki
2018-01-22  3:11     ` David Zarzycki
2018-01-22 17:25     ` Bart Van Assche
2018-01-22 17:40     ` Jens Axboe

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