Date: Sat, 1 Jan 2011 19:26:35 +0200 From: Kostik Belousov <kostikbel@gmail.com> To: Beat G?tzi <beat@chruetertee.ch> Cc: Alexander Best <arundel@freebsd.org>, current@freebsd.org Subject: Re: Suddenly slow lstat syscalls on CURRENT from Juli Message-ID: <20110101172635.GZ90883@deviant.kiev.zoral.com.ua> In-Reply-To: <4D1F5D5E.8030602@chruetertee.ch> References: <4D1F1AE8.5040704@chruetertee.ch> <20110101151008.GA7762@freebsd.org> <4D1F4A48.6080604@chruetertee.ch> <20110101154537.GW90883@deviant.kiev.zoral.com.ua> <4D1F4FB8.3030303@chruetertee.ch> <20110101161254.GX90883@deviant.kiev.zoral.com.ua> <4D1F5992.8030309@chruetertee.ch> <20110101164649.GY90883@deviant.kiev.zoral.com.ua> <4D1F5D5E.8030602@chruetertee.ch>
next in thread | previous in thread | raw e-mail | index | archive | help
--6+qwXIXENytJnbGu Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jan 01, 2011 at 05:59:10PM +0100, Beat G?tzi wrote: > On 01.01.2011 17:46, Kostik Belousov wrote: > > On Sat, Jan 01, 2011 at 05:42:58PM +0100, Beat G?tzi wrote: > >> On 01.01.2011 17:12, Kostik Belousov wrote: > >>> On Sat, Jan 01, 2011 at 05:00:56PM +0100, Beat G?tzi wrote: > >>>> On 01.01.2011 16:45, Kostik Belousov wrote: > >>>>> Check the output of sysctl kern.maxvnodes and vfs.numvnodes. I susp= ect > >>>>> they are quite close or equial. If yes, consider increasing maxvnod= es. > >>>>> Another workaround, if you have huge nested directories hierarhy, is > >>>>> to set vfs.vlru_allow_cache_src to 1. > >>>> > >>>> Thanks for the hint. kern.maxvnodes and vfs.numvnodes were equal: > >>>> # sysctl kern.maxvnodes vfs.numvnodes > >>>> kern.maxvnodes: 100000 > >>>> vfs.numvnodes: 100765 > >>>> > >>>> I've increased kern.maxvnodes and the problem was gone until > >>>> vfs.numvnodes reached the value of kern.maxvnodes again: > >>>> # sysctl kern.maxvnodes vfs.numvnodes > >>>> kern.maxvnodes: 150000 > >>>> vfs.numvnodes: 150109 > >>> The processes should be stuck in "vlruwk" state, that can be > >>> checked with ps or '^T' on the terminal. > >> > >> Yes, there are various processes in "vlruwk" state, > >> > >>>> As the directory structure is quite huge on this server I've set > >>>> vfs.vlru_allow_cache_src to one now. > >>> Did it helped ? > >> > >> No, it doesn't looks like setting vfs.vlru_allow_cache_src helped. The > >> problem was gone when I increased kern.maxvnodes until vfs.numvnodes > >> reached that level. I've stopped all running deamons but numvnodes > >> doesn't decrease. > > Stopping the daemons would not decrease the count of cached vnodes. > > What you can do is to call unmount on the filesystems. Supposedly, the > > filesystems are busy and unmount shall fail, but it will force freed > > the vnodes that are unused by any process. >=20 > That freed around 1500 vnodes. At the moment the vfs.numvnodes doesn't > increase rapidly and the server is usable. I will keep an eye it to see > if I run into the same problem again. This is too small amount of vnodes to be freed for the typical system, and it feels like a real vnode leak. It would be helpful if you tried to identify the load that causes the situation to occur. You are on the UFS, right ? --6+qwXIXENytJnbGu Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (FreeBSD) iEYEARECAAYFAk0fY8sACgkQC3+MBN1Mb4jLOQCfar3tWLQkujs0UZX5YW+OzFJT IzIAn1Oqeuneymr9stKhCWJxgLXd/UwQ =/cZf -----END PGP SIGNATURE----- --6+qwXIXENytJnbGu--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110101172635.GZ90883>