From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin@cygwin.com
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Subject: Re: Deadlock of the process tree when running make
Date: Thu, 7 Apr 2022 17:54:33 -0600 [thread overview]
Message-ID: <23e627a3-39a7-e22f-6372-65d50f1a63d6@SystematicSw.ab.ca> (raw)
In-Reply-To: <9388316255ada0e0fcb2d849cce5a894@ispras.ru>
On 2022-04-07 15:53, Alexey Izbyshev wrote:
> I'm using 32-bit Cygwin 3.3.4 on 64-bit Windows 10 21H2. When running
> parallel make (for testing my project), very rarely I get the whole
> process tree hanging at some seemingly random point. An example of such
> a tree:
>
> make-+-make-+-bash---find
> | |-bash---find
> | |-bash---find
> | |-bash---find
> | |-bash---find
> | `-bash---javac
> `-make-+-bash---bash---bash---readlink
> `-bash---bash---bash-+-grep
> `-grep
>
> (In the above tree, javac is the zombie parent of a native javac, and
> the latter doesn't exist at this point).
>
> I got such hang two times while running make in a loop for several days.
> ProcessHacker shows that all leaf processes are single-threaded and are
> stuck on WaitForSingleObject().
>
> I've skimmed git log of cygwin-3_3-branch after cygwin-3_3_4-release,
> but couldn't find anything that seems definitely related.
>
> Has anybody seen something like this?
>
> Is there any way I can get useful data for diagnosing this hang from the
> process tree that I currently have hanging (I'm going to keep it for
> now)? Otherwise, what would be the best strategy?
I've seen infinite loops with readlink in build scripts under Cygwin.
Seeing that readlink in a process tree makes me suspicious that
something in a shell script is looping because two paths never match or
always match under Cygwin.
Often there is one constant path and a varying path which is subjected
to readlink in a loop.
Under Cygwin, you may have to pass the first path through readlink and
compare that resulting path against the varying value.
--
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
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next prev parent reply other threads:[~2022-04-07 23:54 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-07 21:53 Alexey Izbyshev
2022-04-07 23:54 ` Brian Inglis [this message]
2022-04-08 8:42 ` Alexey Izbyshev
2022-04-08 17:04 ` Brian Inglis
2022-04-11 13:27 ` Alexey Izbyshev
2022-04-09 10:17 ` Takashi Yano
2022-04-09 11:00 ` Alexey Izbyshev
2022-04-09 11:02 ` Alexey Izbyshev
2022-04-09 11:46 ` Takashi Yano
2022-04-09 16:07 ` Alexey Izbyshev
2022-04-09 16:57 ` Takashi Yano
2022-04-09 17:23 ` Alexey Izbyshev
2022-04-09 17:54 ` Takashi Yano
2022-04-09 19:35 ` Alexey Izbyshev
2022-04-09 20:26 ` Alexey Izbyshev
2022-04-10 7:34 ` Takashi Yano
2022-04-10 12:13 ` Alexey Izbyshev
2022-04-10 20:49 ` Alexey Izbyshev
2022-04-11 8:35 ` Takashi Yano
2022-04-11 10:10 ` Alexey Izbyshev
2022-04-13 16:48 ` Alexey Izbyshev
2022-04-13 17:22 ` Takashi Yano
2022-04-13 17:27 ` Alexey Izbyshev
2022-04-13 23:17 ` Alexey Izbyshev
2022-04-16 9:39 ` Takashi Yano
2022-04-16 13:21 ` Alexey Izbyshev
2022-04-27 11:22 ` Takashi Yano
2022-04-27 12:19 ` Alexey Izbyshev
2022-04-11 5:23 ` Jeremy Drake
2022-04-11 8:36 ` Takashi Yano
2022-04-11 15:28 ` Alexey Izbyshev
2022-04-11 17:02 ` Jeremy Drake
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