Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932432AbWJ2UG7 (ORCPT ); Sun, 29 Oct 2006 15:06:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751851AbWJ2UG7 (ORCPT ); Sun, 29 Oct 2006 15:06:59 -0500 Received: from smtp007.mail.ukl.yahoo.com ([217.12.11.96]:32096 "HELO smtp007.mail.ukl.yahoo.com") by vger.kernel.org with SMTP id S1751847AbWJ2UG6 (ORCPT ); Sun, 29 Oct 2006 15:06:58 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.it; h=Received:From:Subject:Date:To:Cc:Bcc:Message-Id:Content-Type:Content-Transfer-Encoding:User-Agent; b=1vQ9578K0QLk3RNKNYlEZo0F+S7IYT6EVrzKzfJITnA62Lrio5nrShhrYgkkd9yQPBc18RiJarD0qUgnMa9JiZWaDHSeXLr1LTK4ALhggpFUbvLv1cINkqnwFvy8DVZ+Bwmrd/vg1SskkRJCn1qKaj1LtoCkTJqjDu1jFXSb0V8= ; From: "Paolo 'Blaisorblade' Giarrusso" Subject: [PATCH 1/2] Make x86_64 udelay() round up instead of down. Date: Sun, 29 Oct 2006 21:07:02 +0100 To: Andrew Morton Cc: Andi Kleen , linux-kernel@vger.kernel.org Message-Id: <20061029200702.26757.12496.stgit@americanbeauty.home.lan> Content-Type: text/plain; charset=utf-8; format=fixed Content-Transfer-Encoding: 8bit User-Agent: StGIT/0.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2379 Lines: 66 From: Paolo 'Blaisorblade' Giarrusso Port two patches from i386 to x86_64 delay.c to make sure all rounding is done upward instead of downward. There is no sign in commit messages that the mismatch was done on purpose, and "delay() guarantees sleeping at least for the specified time" is still a valid rule IMHO. The original x86 patches are both from pre-GIT era, i.e.: "[PATCH] round up in __udelay()" in commit 54c7e1f5cc6771ff644d7bc21a2b829308bd126f "[PATCH] add 1 in __const_udelay()" in commit 42c77a9801b8877d8b90f65f75db758822a0bccc (both commits are from converted BK repository to x86_64). Signed-off-by: Paolo 'Blaisorblade' Giarrusso --- arch/x86_64/lib/delay.c | 4 ++-- include/asm-x86_64/delay.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86_64/lib/delay.c b/arch/x86_64/lib/delay.c index 50be909..7514df0 100644 --- a/arch/x86_64/lib/delay.c +++ b/arch/x86_64/lib/delay.c @@ -40,13 +40,13 @@ EXPORT_SYMBOL(__delay); inline void __const_udelay(unsigned long xloops) { - __delay((xloops * HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32); + __delay((xloops * HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32 + 1); } EXPORT_SYMBOL(__const_udelay); void __udelay(unsigned long usecs) { - __const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */ + __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ } EXPORT_SYMBOL(__udelay); diff --git a/include/asm-x86_64/delay.h b/include/asm-x86_64/delay.h index 65f64ac..40146f6 100644 --- a/include/asm-x86_64/delay.h +++ b/include/asm-x86_64/delay.h @@ -16,7 +16,7 @@ extern void __const_udelay(unsigned long extern void __delay(unsigned long loops); #define udelay(n) (__builtin_constant_p(n) ? \ - ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c6ul)) : \ + ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ __udelay(n)) #define ndelay(n) (__builtin_constant_p(n) ? \ Chiacchiera con i tuoi amici in tempo reale! http://it.yahoo.com/mail_it/foot/*http://it.messenger.yahoo.com - 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/