From owner-freebsd-current@FreeBSD.ORG Mon May 13 15:00:26 2013 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id CCA8412D for ; Mon, 13 May 2013 15:00:26 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 6CF7FCD8 for ; Mon, 13 May 2013 15:00:26 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.7/8.14.7) with ESMTP id r4DF0Ij1092971; Mon, 13 May 2013 18:00:18 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.8.3 kib.kiev.ua r4DF0Ij1092971 Received: (from kostik@localhost) by tom.home (8.14.7/8.14.7/Submit) id r4DF0Ip5092933; Mon, 13 May 2013 18:00:18 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 13 May 2013 18:00:18 +0300 From: Konstantin Belousov To: Roger Pau Monn? Subject: Re: FreeBSD-HEAD gets stuck on vnode operations Message-ID: <20130513150018.GL3047@kib.kiev.ua> References: <5190CBEC.5000704@citrix.com> <5190F9A0.3000005@citrix.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="1Zxv8fCI4MRL5zf7" Content-Disposition: inline In-Reply-To: <5190F9A0.3000005@citrix.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on tom.home Cc: "current@freebsd.org" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 May 2013 15:00:26 -0000 --1Zxv8fCI4MRL5zf7 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 13, 2013 at 04:33:04PM +0200, Roger Pau Monn? wrote: > On 13/05/13 13:18, Roger Pau Monn? wrote: > > The VM can be stuck in this state for quite some time, it generally >=20 > I would like to explain this a little bit more, the syncer process > doesn't get blocked on the _mtx_trylock_flags_ call, it just continues > looping forever in what seems to be an endless loop around > mnt_vnode_next_active/ffs_sync. Also while in this state there is no > noticeable disk activity, so I'm unsure of what is happening. How many CPUs does your VM have ? The loop you describing means that other thread owns the vnode interlock. Can you track what this thread does ? E.g. look at the vp->v_interlock.mtx_lock, which is basically a pointer to the struct thread owning the mutex, clear low bits as needed. Then you can inspect the thread and get a backtrace. Does the loop you described stuck on the same vnode during the whole lock-step time, or is the progress made, possibly slowly ? I suppose that your HEAD is recent. >=20 > > varies between a couple of minutes (5-10min) to an hour or two, after > > this the VM recovers itself and resumes normal operation. I still have > > to test this on a bare metal FreeBSD install, but I would like to ask > > if someone has seen a similar behaviour, or if someone is suspicious of > > a change that could cause this. > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" --1Zxv8fCI4MRL5zf7 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (FreeBSD) iQIcBAEBAgAGBQJRkQABAAoJEJDCuSvBvK1BmMoQAJO66spaQ/rjZQU5Py+sH8T9 mLPVoJ0l494K4ImhqeU1JuvzmGEigqGSJNlZ6AHecsvAxAUiVFWLTo3nOlquMebK vUr3ENOFNia/kPr5KhTYOfxelO6ITwcZFmXBg5USz8EAGbNWscLtMncxQ8P7hHjZ Dx16CEUFeYTnvs1vG0tyse5jCZYhmWqFEg6gIpqViL+GoKNzcSVHOj/SOujqHKlK R2lVVLsI5CHWUAcJ5lHhtwFPuohRV7gnJ2oQA7/exSRuUgNehaL5i5BbRUq/zfls zBSXlHIok6ZzpIXE4NQ+MABw6fO/0jr0VTCl4GwPJ6SHbQ+iEq9s9jjBwMal1So2 SIRQiW4dIfeBusC/ZvrKUPanbzsnZ+J4BNlkq42c8D/wgT1LI8myBj/byzUMuT9S VXWnyC7lXF+i45tYyvtpWWvyffJAtZwKSPmEE1noxEAhk9SWI/Qro0U2WPt+FnGV ZLjL/MgPq1+asqa942DKLQaxlV0sVCSnaGqCs0e/D24rTGuPVHcyZauObcFXWIoe 4YjwLLZra0/BdkokaF2irv4laXwKrDUExWp4aVR23MOOcAabXp7lFT7DsCurrnvG pvgdrO8ryrsWlIZ7W9S2YVDyEx85FvnkwfRtc1EmO9ZjrpALTlIVBW2JbmWtxY5J 8cVWgkvlodohJpPGiO92 =gREQ -----END PGP SIGNATURE----- --1Zxv8fCI4MRL5zf7--