From: Herbert Xu <herbert@gondor.apana.org.au>
To: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Wang Chen <wangchen@cn.fujitsu.com>,
Gerrit Renker <gerrit@erg.abdn.ac.uk>,
davem@davemloft.net, andi@firstfloor.org, netdev@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Christoph Lameter <clameter@sgi.com>, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 3/3] [UDP6]: Counter increment on BH mode
Date: Tue, 4 Dec 2007 00:17:23 +1100 [thread overview]
Message-ID: <20071203131723.GA30312@gondor.apana.org.au> (raw)
In-Reply-To: <20071203115435.GA4202@gondor.apana.org.au>
On Mon, Dec 03, 2007 at 10:54:35PM +1100, Herbert Xu wrote:
>
> Hmm, wasn't someone else talking about a non-atomic version of atomic
> ops lately (i.e., atomic with respect to the local CPU only)? Perhaps
> this is the killer app for it :)
Never mind, we already have that in local_t and as Alexey correctly
points out, USER is still going to be the expensive variant with the
preempt_disable (well until BH gets threaded). So how about this patch?
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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 ea206bf..9444b54 100644
--- a/include/net/snmp.h
+++ b/include/net/snmp.h
@@ -23,6 +23,7 @@
#include <linux/cache.h>
#include <linux/snmp.h>
+#include <linux/smp.h>
/*
* Mibs are stored in array of unsigned long.
@@ -137,7 +138,10 @@ struct linux_mib {
#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
#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]++)
#define SNMP_DEC_STATS(mib, field) \
@@ -145,6 +149,9 @@ struct linux_mib {
#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
next prev parent reply other threads:[~2007-12-03 13:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <474F7EE8.2040009@cn.fujitsu.com>
[not found] ` <474F8255.5060501@cn.fujitsu.com>
[not found] ` <20071130111949.GB28277@gerrit.erg.abdn.ac.uk>
[not found] ` <20071201015438.GC26895@gondor.apana.org.au>
[not found] ` <4753AE07.1040906@cn.fujitsu.com>
[not found] ` <20071203113935.GA25124@gondor.apana.org.au>
[not found] ` <20071203114912.GA4425@ms2.inr.ac.ru>
2007-12-03 11:54 ` [PATCH 3/3] [UDP6]: Counter increment on BH mode Herbert Xu
2007-12-03 13:17 ` Herbert Xu [this message]
2007-12-04 3:50 ` Wang Chen
2007-12-04 3:57 ` Herbert Xu
2007-12-15 13:58 ` Herbert Xu
2007-12-15 17:03 ` Eric Dumazet
2007-12-16 2:30 ` [SNMP]: Fix SNMP counters with PREEMPT Herbert Xu
2007-12-20 12:13 ` David Miller
2007-12-15 18:43 ` [PATCH 3/3] [UDP6]: Counter increment on BH mode Ingo Molnar
2007-12-16 2:36 ` Herbert Xu
2007-12-16 8:58 ` Ingo Molnar
2007-12-17 19:42 ` Christoph Lameter
2007-12-17 19:40 ` Christoph Lameter
2007-12-20 12:12 ` David Miller
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