From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-ext4@vger.kernel.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-block@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: REGRESSION: 37f4a24c2469: blk-mq: centralise related handling into blk_mq_get_driver_tag
Date: Thu, 24 Sep 2020 21:13:11 -0400 [thread overview]
Message-ID: <20200925011311.GJ482521@mit.edu> (raw)
In-Reply-To: <20200924143345.GD482521@mit.edu>
On Thu, Sep 24, 2020 at 10:33:45AM -0400, Theodore Y. Ts'o wrote:
> HOWEVER, thanks to a hint from a colleague at $WORK, and realizing
> that one of the stack traces had virtio balloon in the trace, I
> realized that when I switched the GCE VM type from e1-standard-2 to
> n1-standard-2 (where e1 VM's are cheaper because they use
> virtio-balloon to better manage host OS memory utilization), problem
> has become, much, *much* rarer (and possibly has gone away, although
> I'm going to want to run a lot more tests before I say that
> conclusively) on my test setup. At the very least, using an n1 VM
> (which doesn't have virtio-balloon enabled in the hypervisor) is
> enough to unblock ext4 development.
.... and I spoke too soon. A number of runs using -rc6 are now
failing even with the n1-standard-2 VM, so virtio-ballon may not be an
indicator.
This is why debugging this is frustrating; it is very much a heisenbug
--- although 5.8 seems to work completely reliably, as does commits
before 37f4a24c2469. Anything after that point will show random
failures. :-(
- Ted
next prev parent reply other threads:[~2020-09-25 1:13 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200818181117.GA34125@mit.edu>
[not found] ` <990cc101-d4a1-f346-fe78-0fb5b963b406@kernel.dk>
[not found] ` <20c844c8-b649-3250-ff5b-b7420f72ff38@kernel.dk>
[not found] ` <20200822143326.GC199705@mit.edu>
[not found] ` <aff250ad-4c31-15c2-fa1d-3f3945cb7aa5@kernel.dk>
[not found] ` <7f0e2d99-5da2-237e-a894-0afddc0ace1e@kernel.dk>
[not found] ` <049a97db-c362-bcfb-59e5-4b1d2df59383@kernel.dk>
[not found] ` <5140ba6c-779c-2a71-b7f2-3c3220cdf19c@kernel.dk>
[not found] ` <68510957-c887-8e26-4a1a-a7a93488586a@kernel.dk>
[not found] ` <20200904035528.GE558530@mit.edu>
2020-09-15 4:45 ` REGRESSION: 37f4a24c2469: blk-mq: centralise related handling into blk_mq_get_driver_tag Theodore Y. Ts'o
2020-09-15 7:33 ` Ming Lei
2020-09-15 22:45 ` Theodore Y. Ts'o
2020-09-15 23:09 ` Ming Lei
2020-09-16 20:20 ` Theodore Y. Ts'o
2020-09-17 2:20 ` Ming Lei
2020-09-17 14:30 ` Theodore Y. Ts'o
2020-09-17 23:08 ` Ming Lei
2020-09-24 0:59 ` Ming Lei
2020-09-24 14:33 ` Theodore Y. Ts'o
2020-09-25 1:13 ` Theodore Y. Ts'o [this message]
2020-09-25 7:31 ` Ming Lei
2020-09-25 16:19 ` Ming Lei
2020-09-25 16:32 ` Shakeel Butt
2020-09-25 16:47 ` Shakeel Butt
2020-09-25 17:22 ` Roman Gushchin
2020-09-25 17:17 ` Linus Torvalds
2020-09-25 17:22 ` Shakeel Butt
2020-09-25 17:35 ` Shakeel Butt
2020-09-25 17:47 ` Roman Gushchin
2020-09-25 17:58 ` Shakeel Butt
2020-09-25 19:19 ` Shakeel Butt
2020-09-25 20:56 ` Roman Gushchin
2020-09-25 21:18 ` Shakeel Butt
2020-09-27 17:38 ` Theodore Y. Ts'o
2020-09-26 1:43 ` Ming Lei
2020-09-26 6:42 ` Roman Gushchin
2020-09-25 1:14 ` Ming Lei
2020-09-25 2:34 ` Ming Lei
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