From: Willem Jan Withagen <wjw@digiware.nl>
To: Mykola Golub <mgolub@mirantis.com>
Cc: Ceph Development <ceph-devel@vger.kernel.org>
Subject: Re: Hard to debug problem with ceph_erasure_code
Date: Fri, 1 Apr 2016 14:22:24 +0200 [thread overview]
Message-ID: <56FE6800.7050407@digiware.nl> (raw)
In-Reply-To: <56FE4098.8000209@digiware.nl>
On 1-4-2016 11:34, Willem Jan Withagen wrote:
> On 1-4-2016 07:12, Mykola Golub wrote:
>> On Thu, Mar 31, 2016 at 07:10:45PM +0200, Willem Jan Withagen wrote:
>>
>>> Does anybody have suggestions as how to track/debug this?
>>
>> valgrind?
>>
>
> Yup, tried that one, but it is sort of hard to find an intermittent
> erroneous write. I tried --track-addr=<addr of m_exp_len> But most of
> the time it is only written at exact the code line it is supposed to be
> written. So no info there.
>
> So perhaps I need a different set of tests?
>
> On average I need about 600 runs to catch one SIGSEGV.
>
> BTW: tried it on 2 FreeBSD systems, and on both the behaviour is
> identical. So it has got to be the code. And since 65000 runs on Linux
> give no errors, it is also typical for the combo
> FreeBSD/Clang/FreeBSD-packages.
And it gets even weirder.
Clang allows to use of AddressSanitizer
( https://github.com/google/sanitizers/wiki/AddressSanitizer )
So i've compiled all of ceph with
-fsanitize=address -fno-omit-frame-pointer
And now I've already logged 50.000 runs without crashes.
Feels a lot like Schrödinger's cat....
--WjW
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prev parent reply other threads:[~2016-04-01 12:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-31 17:10 Hard to debug problem with ceph_erasure_code Willem Jan Withagen
2016-04-01 5:12 ` Mykola Golub
2016-04-01 9:34 ` Willem Jan Withagen
2016-04-01 12:22 ` Willem Jan Withagen [this message]
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