From owner-svn-src-head@FreeBSD.ORG  Wed Mar 13 15:43:14 2013
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id 75619100;
 Wed, 13 Mar 2013 15:43:14 +0000 (UTC)
 (envelope-from glebius@FreeBSD.org)
Received: from cell.glebius.int.ru (glebius.int.ru [81.19.69.10])
 by mx1.freebsd.org (Postfix) with ESMTP id EE0F5FBE;
 Wed, 13 Mar 2013 15:43:13 +0000 (UTC)
Received: from cell.glebius.int.ru (localhost [127.0.0.1])
 by cell.glebius.int.ru (8.14.6/8.14.6) with ESMTP id r2DFhC48071092;
 Wed, 13 Mar 2013 19:43:12 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
Received: (from glebius@localhost)
 by cell.glebius.int.ru (8.14.6/8.14.6/Submit) id r2DFhCgM071091;
 Wed, 13 Mar 2013 19:43:12 +0400 (MSK)
 (envelope-from glebius@FreeBSD.org)
X-Authentication-Warning: cell.glebius.int.ru: glebius set sender to
 glebius@FreeBSD.org using -f
Date: Wed, 13 Mar 2013 19:43:12 +0400
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: Andre Oppermann <andre@freebsd.org>
Subject: Re: svn commit: r248196 - head/sys/nfs
Message-ID: <20130313154312.GT48089@FreeBSD.org>
References: <201303121219.r2CCJN5Z069789@svn.freebsd.org>
 <513F3A54.3090702@freebsd.org> <20130312150053.GI48089@FreeBSD.org>
 <513F4A39.8040107@freebsd.org> <20130312155005.GJ48089@FreeBSD.org>
 <513F58C0.4050302@freebsd.org> <20130312194936.GL48089@FreeBSD.org>
 <513F9BC9.3060300@freebsd.org> <20130313151843.GS48089@FreeBSD.org>
 <51409D40.5050408@freebsd.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=koi8-r
Content-Disposition: inline
In-Reply-To: <51409D40.5050408@freebsd.org>
User-Agent: Mutt/1.5.21 (2010-09-15)
Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org,
 src-committers@freebsd.org
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 13 Mar 2013 15:43:14 -0000

On Wed, Mar 13, 2013 at 04:37:36PM +0100, Andre Oppermann wrote:
A> > A> > Let me repeat: there is a lot of code, that does handmade allocation of
A> > A> > an mbuf chain of an arbitrary length using mbufs and common clusters. This
A> > A> > code can be cut and use m_getm2(), if we can restrict it to avoid page size
A> > A> > clusters. I don't have time to dig deeper in the code and analyze and test
A> > A> > whether it can support page sized clusters in chains.
A> > A>
A> > A> m_getm2() can be used in any such case and doesn't have to avoid PAGE_SIZE
A> > A> clusters.  PAGE_SIZE jumbo clusters are fine.  Larger than PAGE_SIZE is not.
A> > A>
A> > A> When the code is able to work with mbuf chains the exact size of each cluster
A> > A> isn't important anymore.  We can use the optimal size.
A> >
A> > Do you volunteer to fix if anything is broken? If not, I'd prefer to
A> > be conservative and make m_getm() capable to produce chains without
A> > clusters bigger than MCLBYTES.
A> 
A> There is nothing to fix.  It works just fine and in fact is in use for all
A> socket i/o (write) for about 6 years since r163916 and 163916.  :-)
A> 
A> Yes, if there is anything broken with PAGE_SIZE mbuf chains returned by m_getm2()
A> I'm volunteering to fix it.

I caught your tongue :) Be prepared to study netipsec code :)

-- 
Totus tuus, Glebius.