From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932227AbXLPCbY (ORCPT ); Sat, 15 Dec 2007 21:31:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758122AbXLPCbM (ORCPT ); Sat, 15 Dec 2007 21:31:12 -0500 Received: from rhun.apana.org.au ([64.62.148.172]:2185 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757704AbXLPCbK (ORCPT ); Sat, 15 Dec 2007 21:31:10 -0500 Date: Sun, 16 Dec 2007 10:30:25 +0800 From: Herbert Xu To: Eric Dumazet Cc: Alexey Kuznetsov , Wang Chen , Gerrit Renker , davem@davemloft.net, andi@firstfloor.org, netdev@vger.kernel.org, Linux Kernel Mailing List , Christoph Lameter , Ingo Molnar Subject: [SNMP]: Fix SNMP counters with PREEMPT Message-ID: <20071216023025.GA959@gondor.apana.org.au> References: <474F8255.5060501@cn.fujitsu.com> <20071130111949.GB28277@gerrit.erg.abdn.ac.uk> <20071201015438.GC26895@gondor.apana.org.au> <4753AE07.1040906@cn.fujitsu.com> <20071203113935.GA25124@gondor.apana.org.au> <20071203114912.GA4425@ms2.inr.ac.ru> <20071203115435.GA4202@gondor.apana.org.au> <20071203131723.GA30312@gondor.apana.org.au> <20071215135851.GA29063@gondor.apana.org.au> <476408D7.50205@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <476408D7.50205@cosmosbay.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 15, 2007 at 06:03:19PM +0100, Eric Dumazet wrote: > > How come you change SNMP_INC_STATS_USER() but not SNMP_INC_STATS() ? Heh, my brain must have blocked me from seeing it because it's too hard :) Let's fix it the stupid way first and I'll do a local_t conversion later. [SNMP]: Fix SNMP counters with PREEMPT The SNMP macros use raw_smp_processor_id() in process context which is illegal because the process may be preempted and then migrated to another CPU. This patch makes it use get_cpu/put_cpu to disable preemption. Signed-off-by: Herbert Xu Thanks, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/include/net/snmp.h b/include/net/snmp.h index 9c5793d..fbb6666 100644 --- a/include/net/snmp.h +++ b/include/net/snmp.h @@ -23,6 +23,7 @@ #include #include +#include /* * Mibs are stored in array of unsigned long. @@ -135,14 +136,26 @@ struct linux_mib { #define SNMP_INC_STATS_BH(mib, field) \ (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++) #define SNMP_INC_STATS_USER(mib, field) \ - (per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++) + do { \ + per_cpu_ptr(mib[1], get_cpu())->mibs[field]++; \ + put_cpu(); \ + } while (0) #define SNMP_INC_STATS(mib, field) \ - (per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++) + do { \ + per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]++; \ + put_cpu(); \ + } while (0) #define SNMP_DEC_STATS(mib, field) \ - (per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--) + do { \ + per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]--; \ + put_cpu(); \ + } while (0) #define SNMP_ADD_STATS_BH(mib, field, addend) \ (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend) #define SNMP_ADD_STATS_USER(mib, field, addend) \ - (per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend) + do { \ + per_cpu_ptr(mib[1], get_cpu())->mibs[field] += addend; \ + put_cpu(); \ + } while (0) #endif