From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750797AbWA2A4V (ORCPT ); Sat, 28 Jan 2006 19:56:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750796AbWA2A4V (ORCPT ); Sat, 28 Jan 2006 19:56:21 -0500 Received: from smtp.osdl.org ([65.172.181.4]:46503 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750778AbWA2A4U (ORCPT ); Sat, 28 Jan 2006 19:56:20 -0500 Date: Sat, 28 Jan 2006 16:55:49 -0800 From: Andrew Morton To: Benjamin LaHaise Cc: dada1@cosmosbay.com, kiran@scalex86.org, davem@davemloft.net, linux-kernel@vger.kernel.org, shai@scalex86.org, netdev@vger.kernel.org, pravins@calsoftinc.com Subject: Re: [patch 3/4] net: Percpufy frequently used variables -- proto.sockets_allocated Message-Id: <20060128165549.262f2b90.akpm@osdl.org> In-Reply-To: <20060129004459.GA24099@kvack.org> References: <20060126185649.GB3651@localhost.localdomain> <20060126190357.GE3651@localhost.localdomain> <43D9DFA1.9070802@cosmosbay.com> <20060127195227.GA3565@localhost.localdomain> <20060127121602.18bc3f25.akpm@osdl.org> <20060127224433.GB3565@localhost.localdomain> <43DAA586.5050609@cosmosbay.com> <20060127151635.3a149fe2.akpm@osdl.org> <43DABAA4.8040208@cosmosbay.com> <20060129004459.GA24099@kvack.org> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Benjamin LaHaise wrote: > > On Sat, Jan 28, 2006 at 01:28:20AM +0100, Eric Dumazet wrote: > > We might use atomic_long_t only (and no spinlocks) > > Something like this ? > > Erk, complex and slow... Try using local_t instead, which is substantially > cheaper on the P4 as it doesn't use the lock prefix and act as a memory > barrier. See asm/local.h. > local_t isn't much use until we get rid of asm-generic/local.h. Bloaty, racy with nested interrupts.