From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755887AbbHYQx4 (ORCPT ); Tue, 25 Aug 2015 12:53:56 -0400 Received: from smtprelay0202.hostedemail.com ([216.40.44.202]:42794 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754893AbbHYQxz (ORCPT ); Tue, 25 Aug 2015 12:53:55 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::,RULES_HIT:41:355:379:541:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2828:3138:3139:3140:3141:3142:3352:3865:3866:3867:3870:3872:4321:4605:5007:6119:6261:7903:8603:8660:10004:10400:10848:11026:11658:11914:12296:12517:12519:12555:12679:12700:12737:13069:13148:13161:13229:13230:13311:13357:14394:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: run70_5c19508ab045a X-Filterd-Recvd-Size: 2296 Message-ID: <1440521631.2670.100.camel@perches.com> Subject: [PATCH] cred: Remove unnecessary kdebug atomic reads From: Joe Perches To: David Howells , James Morris Cc: Andrew Morton , LKML Date: Tue, 25 Aug 2015 09:53:51 -0700 Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.12.11-0ubuntu3 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit e0e817392b9a ("CRED: Add some configurable debugging [try #6]") added the kdebug mechanism to this file back in 2009. The kdebug macro calls no_printk which always evaluates arguments. Most of the kdebug uses have an unnecessary call of atomic_read(&cred->usage) Make the kdebug macro do nothing by defining it with do { if (0) no_printk(...); } while (0) when not enabled. $ size kernel/cred.o* (defconfig x86-64) text data bss dec hex filename 2748 336 8 3092 c14 kernel/cred.o.new 2788 336 8 3132 c3c kernel/cred.o.old Miscellanea: o Neaten the #define kdebug macros while there Signed-off-by: Joe Perches --- kernel/cred.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/cred.c b/kernel/cred.c index ec1c076..71179a0 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -20,11 +20,16 @@ #include #if 0 -#define kdebug(FMT, ...) \ - printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__) +#define kdebug(FMT, ...) \ + printk("[%-5.5s%5u] " FMT "\n", \ + current->comm, current->pid, ##__VA_ARGS__) #else -#define kdebug(FMT, ...) \ - no_printk("[%-5.5s%5u] "FMT"\n", current->comm, current->pid ,##__VA_ARGS__) +#define kdebug(FMT, ...) \ +do { \ + if (0) \ + no_printk("[%-5.5s%5u] " FMT "\n", \ + current->comm, current->pid, ##__VA_ARGS__); \ +} while (0) #endif static struct kmem_cache *cred_jar;