From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [net-next PATCH 3/3] net: frag queue per hash bucket locking Date: Thu, 28 Mar 2013 15:03:59 -0400 (EDT) Message-ID: <20130328.150359.1119974430252894273.davem@davemloft.net> References: <20130327155601.15203.25289.stgit@dragon> <1364405159.15753.26.camel@edumazet-glaptop> <20130328185721.GA20223@order.stressinduktion.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: eric.dumazet@gmail.com, brouer@redhat.com, netdev@vger.kernel.org, fw@strlen.de, dborkman@redhat.com To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:44547 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751335Ab3C1TED (ORCPT ); Thu, 28 Mar 2013 15:04:03 -0400 In-Reply-To: <20130328185721.GA20223@order.stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Hannes Frederic Sowa Date: Thu, 28 Mar 2013 19:57:21 +0100 > On Wed, Mar 27, 2013 at 10:25:59AM -0700, Eric Dumazet wrote: >> On Wed, 2013-03-27 at 16:56 +0100, Jesper Dangaard Brouer wrote: >> > This patch implements per hash bucket locking for the frag queue >> > hash. This removes two write locks, and the only remaining write >> > lock is for protecting hash rebuild. This essentially reduce the >> > readers-writer lock to a rebuild lock. ... >> I am not sure why you added _bh suffix to spin_lock()/spin_unlock() >> here ? > > I assume that it has to do with the usage of this code in > ipv6/netfilter/nf_conntrack_reasm.c, which could be invoked from process > context, if I read it correctly. That appears to be the case yes. That's an odd environment for these routines to be invoked from, so longer term we should probably make the nf conntrack code do the BH disabling around the inet frag calls, rather than make the inet frag code eat the extra overhead for the more common invocations.