Date: Wed, 13 Feb 2013 22:30:42 +0200 From: Konstantin Belousov <kostikbel@gmail.com> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: Marc Fournier <scrappy@hub.org>, Kostik Belousov <kib@freebsd.org>, freebsd-stable@freebsd.org, John Baldwin <jhb@freebsd.org> Subject: Re: 9-STABLE -> NFS -> NetAPP: Message-ID: <20130213203042.GW2522@kib.kiev.ua> In-Reply-To: <339364797.2960794.1360720239431.JavaMail.root@erie.cs.uoguelph.ca> References: <61DAA500-EB20-4861-AA7F-402FF1047B81@hub.org> <339364797.2960794.1360720239431.JavaMail.root@erie.cs.uoguelph.ca>
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--nk8TfLPx+OTa8gAE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Feb 12, 2013 at 08:50:39PM -0500, Rick Macklem wrote: > Marc Fournier wrote: > > Just reset server, so any further details will have to be 'next time' > > ??? but, just did a csup and am rebuilding ??? the following three files > > were modified since last build: > >=20 > > grep nfs /tmp/output > > Edit src/sys/fs/nfs/nfs_commonsubs.c > > Edit src/sys/fs/nfsclient/nfs_clrpcops.c > > Edit src/sys/fs/nfsserver/nfs_nfsdserv.c > >=20 > >=20 > > On 2013-02-10, at 4:56 PM, Marc Fournier <scrappy@hub.org> wrote: > >=20 > > > > > > On 2013-02-10, at 4:31 PM, Rick Macklem <rmacklem@uoguelph.ca> > > > wrote: > > > > > >> Marc Fournier wrote: > > >>> Hi John ??? > > >>> > > >>> Does this help? > > >>> > > >>> root@io:~ # ps auxl | grep du > > >>> root 1054 0.0 0.1 16176 6600 ?? D 3:15AM 0:05.38 du -skx /vm/2799 > > >>> 0 > > >>> 81426 0 20 0 newnfs > > >>> root 12353 0.0 0.1 16176 5104 ?? D Sat03AM 0:05.41 du -skx > > >>> /vm/2799 0 > > >>> 91597 0 20 0 newnfs > > >>> root 64529 0.0 0.1 16176 5164 ?? D Fri03AM 0:05.40 du -skx > > >>> /vm/2799 0 > > >>> 43227 0 20 0 newnfs > > >>> root 12855 0.0 0.0 16308 1988 0 S+ 5:26AM 0:00.00 grep du 0 12847 > > >>> 0 20 > > >>> 0 piperd > > >> It is probably too late, but all the lines (without the | grep du) > > >> would be > > >> more useful. I also include the "H" flag, so it lists threads as > > >> well as > > >> processes. The above just says the "du" command is waiting for a > > >> vnode lock. > > >> The interesting process/thread is the one that is holding a vnode > > >> lock > > >> while waiting for something else. > > > > > > As requested, 'ps auxlH' attached ??? > > > > > > > > > <ps.out.bz2> > > > > Well, I took a look at the ps output and I didn't see anything that would > identify what the hang is. There are a lot of processes sleeping on "newn= fs" > (waiting for a vnode lock) and many sleeping on "vofflock" (waiting for t= he > f_offset lock). I never got any attachments on the thread. See http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kernel= debug-deadlocks.html for the description of what is needed to start debugging. >=20 > Unfortunately, I can't spot any process/thread that is blocked on somethi= ng > else, where it would seem likely to be holding either an nfs vnode lock or > f_offset lock that isn't one of these. >=20 > There were changes about 5 months ago which it appears fixed a deadlock r= ace > between vnode locks and offset locks for paging (r236321 and friends). No, I do not think that the description of the changes is right. >=20 > I am wondering if there could be other similar races, possibly specific to > paging in over NFS? (I can't see any case where there is a LOR, so I can't > think of what it might be?) >=20 > If you just want the hangs to go away, I'd suggest moving the executable > is /usr/local/sbin (httpd maybe) to a local file system on the server, > since it does seem to be related to paging this executable in over NFS. >=20 > rick > ps: I've added kib@ to the cc, in case he is aware of other related races? >=20 > > >> > > >> Are you still getting the: > > >> nfs_getpages: error 13 > > >> vm_fault: pager read error, pid 11355 (https) > > > > > > Fairly quiet: > > > > > > <Screen Shot 2013-02-10 at 4.43.55 PM.png> > > > > > > And that is it since last reboot ~20 days ago ??? > > > > > >> > > >> messages logged? > > >> > > >> With John's recent patch, the error# would no longer be 13 if it > > >> was > > >> caused by the "intr" flag resulting in a Read RPC terminating with > > >> EINTR. > > >> If you are still getting the above with "error 13", it suggests > > >> that > > >> the server is replying EACCES for the Read RPC. > > >> I suggested before that you check to make sure that the executable > > >> had > > >> read access for everyone one the file server. Since I didn't hear > > >> back, > > >> I'll assume this is the case. > > > > > > Don't understand this question ??? I have 34 VPSs running off of this > > > server right now ??? that 'du process' runs against each of those VPSs > > > every night, and this problem started happening on Friday night's > > > run ??? ~18 days into uptime ??? so the same process has run repeated= ly, > > > with no issues, 18 times before it hung on Friday ??? also, the hang, > > > once 'triggered', only seems to recur against the same directory ??? > > > the same directory doesn't necessarily trigger it, but once it > > > starts, it appears to do it for the same directory ??? I'm not sure if > > > I've ever seem it happening to two different directories at the same > > > time ??? > > > > > > Also, please note that the du command is run from the physical > > > server, as root ??? > > > > > >> rick > > >> ps: If it is still up and hasn't been rebooted, you could: > > >> sysctl debug.kdb.break_to_debugger=3D1 > > >> - then type <ctrl><alt><esc> at the console and do the following > > >> from the debugger > > >> http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbo= ok/kerneldebug-deadlocks.html > > >> How well this work depends on what options your kernel was built > > >> with. > > > > > > My remote console on that one doesn't work very well ??? I can view, > > > but I can't type ??? > > > > > > > >=20 > > _______________________________________________ > > freebsd-stable@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > > To unsubscribe, send any mail to > > "freebsd-stable-unsubscribe@freebsd.org" --nk8TfLPx+OTa8gAE Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQIbBAEBAgAGBQJRG/fxAAoJEJDCuSvBvK1B2UEP900T6fi2b5piJ0L56tvYkmVk xc8UeWip1JFCoEoHwe1BNh26QlDJ3QXHwKSzBtlg14+U+v2Q3wI5d90w8/7mOZj9 JfICggaXhzR6by/Ob8v109kKyfK3vFQOB3k7leyX2ZscXnO9D+1o+cfuWezmAtF4 pDxQrajkBIRb3cAVsB8JxwMJCQo0wiSlziE8QZh1qU6k5PzrjmxEgOtFZxLKBCSj lFyFdPb2QCUV4FdoNOYPYlpX9cHOXlmwOwuZFkBSUqrTdyI8USoQ4q/XeAbc0k9N 50w734CIR5wHQAvnsnfw2vVPnB1KAB5RknSxmzsGMmmZQIbOItu1X7JrVxD9kh1C KqK25mfJm3D16/qLvkv4pq0Iwpfypb8jutDltKbNdngaTFLyeuF3IY7w9opxFtCd FjrvtRL2kOJEDP2mAHoTPL9t/gJrLX57EqpJIxZvYawqiORtal3YCi6JcgaE9ElU 3ZbB157KuhJvxf6YPfConIBdWKtMKUgclyuYBELqgFDIVnl4SnU+3wpJD0ADea7/ 0GIwWKHjpd+PNdRbOaeeLg7leJIdzqxET8Sk+hO+L4eNx/1mZjIxaDnYpyOosJ4B E+rr02qXsvO3ztZJ6QUWMJSMFpArbZODEunMBcl/On776/hPIyWPbSkmrHlymB3X 5lEGVBr4m7vHtJabc6E= =bBcd -----END PGP SIGNATURE----- --nk8TfLPx+OTa8gAE--
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