From owner-svn-src-stable-7@FreeBSD.ORG Wed Apr 8 14:49:06 2009 Return-Path: Delivered-To: svn-src-stable-7@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D04BA106564A; Wed, 8 Apr 2009 14:49:06 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from fk-out-0910.google.com (fk-out-0910.google.com [209.85.128.190]) by mx1.freebsd.org (Postfix) with ESMTP id 0F25B8FC16; Wed, 8 Apr 2009 14:49:05 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: by fk-out-0910.google.com with SMTP id b27so79804fka.11 for ; Wed, 08 Apr 2009 07:49:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=rSxgeKylvEYjgy+H7x4pZphk1ValLw264vPKjOMFLiQ=; b=E8uGAMfREVAvcn9B9kMEpFBoIZ6GAXo4LVMn/bxKkV8PNY0HazT1cyQImtSoIxjxTC z9NEGedrrLPksjWVLVmmdiiKZnj6c2myxLzi/QKV2Lt5rDmxW+XDlkRjd8L7+gw1SkJK E1uOePpOJXvWIHVFzLeqlmbkIOQh0hU+Qx1b4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=PmZkzMsWU2kEGlBtV6UfLcrImxOhG3GKH31xs9oSDueQkYmb4V/wdeauV4B4rIDM0z YeaAyXu5W1xRaDYAQ78n60oiqu9893lUOIl4+JSMX9TrtmvSJT7d6sn/3KoO5KWeyJQl ZpHPRIrSi5YT/c5GvyTst8Yi98kORcC9JzTIA= MIME-Version: 1.0 Sender: asmrookie@gmail.com Received: by 10.103.245.18 with SMTP id x18mr586250mur.62.1239200676161; Wed, 08 Apr 2009 07:24:36 -0700 (PDT) In-Reply-To: References: <200904080430.n384UGWw043589@svn.freebsd.org> Date: Wed, 8 Apr 2009 16:24:36 +0200 X-Google-Sender-Auth: 22042fdc5f27f1eb Message-ID: <3bbf2fe10904080724i381c36fdpb1699def955fdb6d@mail.gmail.com> From: Attilio Rao To: Robert Watson Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: svn-src-stable@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, svn-src-stable-7@freebsd.org, Stephen McKay Subject: Re: svn commit: r190837 - in stable/7/sys: . contrib/pf dev/ath/ath_hal dev/cxgb kern X-BeenThere: svn-src-stable-7@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for only the 7-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Apr 2009 14:49:07 -0000 2009/4/8, Robert Watson : > On Wed, 8 Apr 2009, Stephen McKay wrote: > > > > Author: mckay > > Date: Wed Apr 8 04:30:16 2009 > > New Revision: 190837 > > URL: http://svn.freebsd.org/changeset/base/190837 > > > > Log: > > MFC r187460: Add a limit on namecache entries. > > > > Obviously, having a limit is a good idea, but I wonder if we should use > some more mature scheme to limit entries. At the very least, using UMA zone > limits may help memory being dedicated to cache entries without being able > to actually use it (i.e., extra entries in the UMA cache above the > desiredvnodes limit). > > Similarly, the cost of different cache entries is different -- long entries > cost much, much more than short ones, because we use two bucket sizes. > Perhaps this means that we should separately count long and short entries, > and short ones should contribute less towards the limit than long ones? > > Finally, I think it would be a good idea to do a bit of real-world > profiling on memory efficiency of the name cache: how much memory is wasted > when assumptions about short/long are wrong, and could we retune lengths, > limits, hash bucket counts, etc, to work better in practice? Am I wrong or you were working on adding DTrace tracing to it? Do you have any interesting workload/numbers you can show? Thanks, Attilio -- Peace can only be achieved by understanding - A. Einstein