Date: Tue, 23 Oct 2007 10:00:03 GMT From: Kostik Belousov <kostikbel@gmail.com> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/104406: [ufs] Processes get stuck in "ufs" stateunderpersistent CPU load Message-ID: <200710231000.l9NA03hm055576@freefall.freebsd.org>
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The following reply was made to PR kern/104406; it has been noted by GNATS. From: Kostik Belousov <kostikbel@gmail.com> To: bug-followup@FreeBSD.org Cc: Oleg Derevenetz <oleg@vsi.ru> Subject: Re: kern/104406: [ufs] Processes get stuck in "ufs" stateunderpersistent CPU load Date: Tue, 23 Oct 2007 12:54:15 +0300 --wIc/V6YLA2QdyfT4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 22, 2007 at 04:29:32PM +0400, Oleg Derevenetz wrote: > I posted a followup to kern/104406 that includes all information listed i= n=20 > "Debugging Deadlocks" chapter of FreeBSD Developer's Handbook. Can anyone= =20 > take a look on it and say - is this certainly a hardware problem or some= =20 > sort of software problem ? The ps output from ddb would simplify the analysis. The buffer space on the machine seems to be contaminated with a critical amount of the dirty buffers that are sent for the write. The pid 844 (that is the only one producing the writes) is blocked in waitrunningbufspace(), waiting for the write queue to be drained. There are other processes, for instance, 937 etc, that wait for the buffer lock. Most likely, these buffers are scheduled for write and cause the processes to be uninterruptibly blocked. If this state of the system is static, then the write queue is not processed. Most plausible cause is the controller (mly0) or the controller driver fault. --wIc/V6YLA2QdyfT4 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFHHcTGC3+MBN1Mb4gRAodzAKDLMJIiPnjWNRejDrnj/6R/Kic1LwCbBxK+ 9GLcje2brT6bTZA1dzB17Yg= =2chV -----END PGP SIGNATURE----- --wIc/V6YLA2QdyfT4--
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