From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 101002 invoked by alias); 25 Mar 2018 10:24:37 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 100969 invoked by uid 89); 25 Mar 2018 10:24:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-98.4 required=5.0 tests=AWL,BAYES_50,GOOD_FROM_CORINNA_CYGWIN,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.2 spammy=inglis, Inglis, Brian, brian X-HELO: mout.kundenserver.de Received: from mout.kundenserver.de (HELO mout.kundenserver.de) (212.227.126.187) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 25 Mar 2018 10:24:29 +0000 Received: from calimero.vinschen.de ([24.134.7.25]) by mrelayeu.kundenserver.de (mreue006 [212.227.15.167]) with ESMTPSA (Nemesis) id 0Ljxmg-1eScwv2i3m-00c6Hu for ; Sun, 25 Mar 2018 12:24:23 +0200 Received: by calimero.vinschen.de (Postfix, from userid 500) id 8D3F0A8061D; Sun, 25 Mar 2018 12:24:22 +0200 (CEST) Date: Sun, 25 Mar 2018 18:12:00 -0000 From: Corinna Vinschen To: cygwin@cygwin.com Subject: Re: Odd hang in python waiting for child; strace wakes hung process? Message-ID: <20180325102422.GC14026@calimero.vinschen.de> Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com References: <877eq5fedf.fsf@Rainer.invalid> <20180322165908.GI6761@calimero.vinschen.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3siQDZowHQqNOShm" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.2 (2017-12-15) X-UI-Out-Filterresults: notjunk:1;V01:K0:gq3iJR8jhRE=:fjKQ+Cg5PSe2Im9hdtmcDD IkpN3qR/EYCwfLHgNzVC0/O3K1WT4ega2DmJUl8MzcE7pRhafPJhwguddu7AGUDEM9IUic8R4 bETw7t7NTwJZTy5G1bjgz0zNCi7j8Aqdg84Uf9jJKsq8Q8oCn1EHJrhaXgLxtxxc0qgnWoQiI D8D6+aroipbrkZ+4XvwOLDLDNg0eNW6/xDtEytIRInFSXraK1vkOW1awrIyieHeANAy6CPdeC DDByGK1vfanm3IDPrji2JXECoGO0T4H7BJ/vGddEHqTOJPSx2wAypgkOXkbarWSaW4kqlzQZK rjKleoiFLN8Jt/c4IEg11C2Dxr8zgVf+a4l2sVc65Rdiq9ECCY/wcIMZthtf5L8eFjdFcHsOF uYRYfNPw/f+3ClV0D22gcG8P62GCR6/3cVoNQjSWUr0IErrVEhbJkkavLs8KA/JtlJVUaJixi wkY7wsjs9/LTwquuLOY0XMHadnXErFi/F8MsqeAUojZOwO030GAzjh2ye0SGvTXj0Qr9InZ+l GH9upz9LHiDVyfx2qllGBnCOzYiTGw2zJ7+/x0Slz9naTbna+OjyTx2TohAcSvHXmCwCBoMdP AeCGGOI0BzpMlGvvwOP6HJuS1Edrqltffg0d+A4V99Z7hOzGYypyBo+5WXJ2rJcJhjSqfqMH9 cEcHsMfaGFAjEivG0shJk95yPaagczORalQNwYgf0Xg9BahsK7YoxCytlYcPqfJERGPzbWtSe Y4GTIhfqAFeCsjXUsEYULvOlXmTQ4VG7mKGLKA== X-SW-Source: 2018-03/txt/msg00405.txt.bz2 --3siQDZowHQqNOShm Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-length: 2618 On Mar 23 19:21, Brian Inglis wrote: > On 2018-03-22 10:59, Corinna Vinschen wrote: > > On Mar 21 23:41, Brian Inglis wrote: > >> On 2018-03-21 16:07, Dan Kegel wrote: > >>> On Wed, Mar 21, 2018 at 11:54 AM, Achim Gratz wro= te: > >>>> Well, with the sporadic hanging/defunct processes at work my routine= is > >>>> to send CONT to all Cygwin processes, then HUP/KILL to anything that= 's > >>>> still not live or gone and then another round of CONT. This works > >>>> _most_ of the time, anything more stubborn I /bin/kill -f usually. > >>> > >>> Since I wrote, both bots hung again. This time I verified: > >>> 0) both had the defunct git process as expected > >>> 1) kill -CONT the-pid doesn't do anything, nor does kill -9. It's tr= uly wedged. > >>> 2) the process stays in its spin hang until you ^C strace -p the-pid > >>> 3) ^C-ing the strace causes the process to terminate (strace alone do= esn't) > >>> 4) taskkill /pid the-task /f also kills the process successfully. > >>> > >>> So I could write a script that watched for defunct git processes > >>> and taskkilled their parent. Build jobs would fail, but at least > >>> the bot would stay up. Of course it would be much nicer if > >>> the cygwin python process didn't get wedged. > >>> > >>> Alternately, I suppose I could try running native python... > >>> or cygwin's python3... but dangit, kill -9 should work. > >> > >> Seems to be looping on access failure to a Windows mailslot; not sure = what this > >> feature is normally used for: dmesg/syslog messages/AF_UNIX sockets? > >=20 > > /dev/kmsg is implemented using a mailslot under the hood. This > > feature is only used to log exceptions and for nothing else since > > nobody ever found another reason to use it for. > >=20 > > It would be interesting to learn if the perl hangs have the same reason. > >=20 > > I guess we can simply remove /dev/kmsg support completely and drop > > the mailslot code. I'm pretty sure nobody would miss it. Hardly > > anybody knows it exists... >=20 > Is /dev/log implemented the same way? No. /dev/log is a AF_UNIX socket. > Looks like syslog-ng stopped working around the last upgrade: >=20 > $ cat /var/log/syslog-ng.log > Error reading serialized data; error=3D'Error reading file (short read)' > Persistent configuration file is in invalid format, ignoring; > Error binding socket; addr=3D'AF_UNIX(/dev/log)', error=3D'Address alread= y in use (112)' rm -rf /dev/log Corinna --=20 Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat --3siQDZowHQqNOShm Content-Type: application/pgp-signature; name="signature.asc" Content-length: 833 -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEoVYPmneWZnwT6kwF9TYGna5ET6AFAlq3eNYACgkQ9TYGna5E T6A++w//c2vbA+LCy/Biznv/DkRFLiu2OGkbNI2619nXLKUpsVbGFIwBwpDPEXnV Wl0aEhpO/NnBqRffIpkfZoJtjPliGEuAVZLW9odVHmGKLlfLM3mVh0Z1ptRAjUda 2LLMrbYkV5VS/woEPzTGeilv5f8XU4mworW2w4KlELR1bwe4N7TT8teqRT9MfGiW ntTUcTtK9SsKeSI7OSK5zWbOQpy9MkuDQCFlYGSCkHXqnUXjm9pxZ6ur4E7bS3dL /hzy+gqD4i58zoQeZFIgy3qo724Mnlr/XFE0mYsARxhbH9xKBNj+nKU17XI9qe/C zzDimZzQy+3ks0v/ziSQfRzt+m/QB+ndgawAvFl7f4LGnNhegVKPYNGSPT9pfovB EHrpiJWQ8rzE3SvzyVbqaT5HMsDnLfW78rpJc3RM4ze8RSvSsNc/nyT51XrPL78o 0LVByfaDR1I6b/IlcMo1ZzP2tawUs3AvQ9oDTiK2/ouFMRA8EmSvzaJawiJNIfS8 sm8+YISa0frB/kvF/W0fvV+KyJnoF7KyGdgoK1G32mw7pQrYVIcbA3PT/+GUbrPm fZw58lKtJxsskJtQlI2mKFD7fCwXMQvZ4b9TVqNpUg2DcYVhxBhNsL2s6SpvoWKa 1bUNxRtW+3ODJhKiEq2i5zMscldmofBR9b7F2NobNVAMJs6HQ3Q= =7wRw -----END PGP SIGNATURE----- --3siQDZowHQqNOShm--