From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next-2.6] loopback: Implement 64bit stats on 32bit arches Date: Mon, 14 Jun 2010 23:14:12 -0700 (PDT) Message-ID: <20100614.231412.39191304.davem@davemloft.net> References: <1276531162.2478.121.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, bhutchings@solarflare.com To: eric.dumazet@gmail.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:35927 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750874Ab0FOGOB (ORCPT ); Tue, 15 Jun 2010 02:14:01 -0400 In-Reply-To: <1276531162.2478.121.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Mon, 14 Jun 2010 17:59:22 +0200 > Uses a seqcount_t to synchronize stat producer and consumer, for packets > and bytes counter, now u64 types. > > (dropped counter being rarely used, stay a native "unsigned long" type) > > No noticeable performance impact on x86, as it only adds two increments > per frame. It might be more expensive on arches where smp_wmb() is not > free. > > Signed-off-by: Eric Dumazet Applied, but I suspect we might end up eventually needing to abstract this kind of technique in a common place so other spots can use it.