Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030358AbWA1AlX (ORCPT ); Fri, 27 Jan 2006 19:41:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030357AbWA1AlW (ORCPT ); Fri, 27 Jan 2006 19:41:22 -0500 Received: from smtp.osdl.org ([65.172.181.4]:35224 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1030354AbWA1AlV (ORCPT ); Fri, 27 Jan 2006 19:41:21 -0500 Date: Fri, 27 Jan 2006 16:43:08 -0800 From: Andrew Morton To: Eric Dumazet Cc: 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: <20060127164308.1ea4c3e5.akpm@osdl.org> In-Reply-To: <43DABAA4.8040208@cosmosbay.com> 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> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-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 Content-Length: 757 Lines: 22 Eric Dumazet wrote: > > > > > An advantage of retaining a spinlock in percpu_counter is that if accuracy > > is needed at a low rate (say, /proc reading) we can take the lock and then > > go spill each CPU's local count into the main one. It would need to be a > > very low rate though. Or we make the cpu-local counters atomic too. > > We might use atomic_long_t only (and no spinlocks) Yup, that's it. > Something like this ? > It'd be a lot neater if we had atomic_long_xchg(). - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/