From owner-freebsd-hackers@FreeBSD.ORG Thu Nov 13 21:40:04 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1C6A4106567D for ; Thu, 13 Nov 2008 21:40:04 +0000 (UTC) (envelope-from freebsd-hackers@m.gmane.org) Received: from ciao.gmane.org (main.gmane.org [80.91.229.2]) by mx1.freebsd.org (Postfix) with ESMTP id BDE278FC1C for ; Thu, 13 Nov 2008 21:40:03 +0000 (UTC) (envelope-from freebsd-hackers@m.gmane.org) Received: from root by ciao.gmane.org with local (Exim 4.43) id 1L0jv0-0000HS-F2 for freebsd-hackers@freebsd.org; Thu, 13 Nov 2008 21:40:02 +0000 Received: from 93-138-121-139.adsl.net.t-com.hr ([93.138.121.139]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 13 Nov 2008 21:40:02 +0000 Received: from ivoras by 93-138-121-139.adsl.net.t-com.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 13 Nov 2008 21:40:02 +0000 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-hackers@freebsd.org From: Ivan Voras Date: Thu, 13 Nov 2008 22:34:38 +0100 Lines: 66 Message-ID: References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigAE6A6262578BE2789691D2E7" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 93-138-121-139.adsl.net.t-com.hr User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) In-Reply-To: X-Enigmail-Version: 0.95.7 Sender: news Cc: freebsd-questions@freebsd.org Subject: Re: 128 Bucket Failures? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Nov 2008 21:40:04 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigAE6A6262578BE2789691D2E7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Chris Pratt wrote: > I have asked this before a couple of years ago but received no > replies. I assumed that's because it's a somewhat obscure question. > I'm still interested and thought I might try again in case someone > new is watching this list who might know. >=20 > A vmstat -z on my highest traffic server always shows the failures > as below on 128 Bucket. It also goes to having 0 free rather soon > after the system is restarted and never returns to having more than > 1 free in that column and yet always has the highest number of > requests by far. Does this mean anything significant? Is it > something I should tune or even can be tuned? UMA buckets seem to be some kind of cache for SMP-optimized allocations - I hope someone who knows it better will explain them. > Here is the output of the vmstat -z with everything chopped out > besides the 128 Bucket line. The machine it's on is an 8 core 8 GB > Tyan and shouldn't really be starved for anything in my way of thinking= =2E >=20 > vmstat -z > ITEM SIZE LIMIT USED FREE REQUESTS = FAILURES >=20 > 128 Bucket: 1048, 0, 2043, 0, 13591, = 6511069 What is the server used for? Here's a snapshot from a very loaded apache+php+pgsql web server, uptime 60 days (since the last power outage): 16 Bucket: 76, 0, 42, 58, 125, 0 32 Bucket: 140, 0, 76, 64, 183, 0 64 Bucket: 268, 0, 74, 38, 438, 11 128 Bucket: 524, 0, 2060, 642, 788828, 6985 A generic advice would be to increase vm.kmem_size (you're using AMD64, right?) and see what happens. --------------enigAE6A6262578BE2789691D2E7 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkkcnW4ACgkQldnAQVacBchxCQCeOS5FKqQwoOrdNnZUpAQ+q0dx a7sAn1H5KrZVUKwKOkb4uVB/aSCmzWxt =RJ3Z -----END PGP SIGNATURE----- --------------enigAE6A6262578BE2789691D2E7--