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From: Eugene Petrenko <eugene.petrenko@gmail.com>
To: git@vger.kernel.org
Subject: deadlock git upload-pack command when GIT_TRACE is enabled
Date: Mon, 9 May 2016 19:49:01 +0200	[thread overview]
Message-ID: <CAJNyVBAr7dJFxXA2+dXCJUMs=mB9u3-Ja7r4wemk9C_HBZ3W2A@mail.gmail.com> (raw)

Hello,

I stuck around the deadlock inside git when running git upload-pack .
command. A debugging shown that the bottom process (it starts several
processes to implement the task) hangs writing to stderr. I managed to
reproduce the issue with a tiny bash script. The repository and the
script is found here
https://github.com/jonnyzzz/git-upload-pack-deadlock

I saw the issue reproducing both under Windows and Linux/Mac.

Windows thread dumps are available here
https://github.com/jonnyzzz/git-upload-pack-deadlock/tree/master/debug


According to those thread dumps I see the following problem around
upload-pack.c line 129. There the pack_objects command is executed.
First the wants block is pushed to the command, next the stdout
processing is started. This means, that pack_objects process output is
not processed until all output is put there. In the case I have, the
pack_objects process writes TRACE logging into stderr and eventually
(on hug repo) the OS buffer runs-out deadlocking the execution.


Best regards,
Eugene Petrenko

             reply	other threads:[~2016-05-09 17:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-09 17:49 Eugene Petrenko [this message]
2016-05-09 17:53 ` deadlock git upload-pack command when GIT_TRACE is enabled Stefan Beller
2016-05-09 17:54   ` Stefan Beller

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