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From: Denis Cheng <crquan@gmail.com>
To: trivial@kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization
Date: Mon, 18 Jun 2007 03:05:15 -0700 (PDT)	[thread overview]
Message-ID: <467658db.0f98600a.5a55.ffffdd79@mx.google.com> (raw)

From: Denis Cheng <crquan@gmail.com>

the explicit memset call could be optimized out by data initialization,
thus all the fill working can be done by the compiler implicitly.

Signed-off-by: Denis Cheng <crquan@gmail.com>

---
Is there some comments on this?

--- arch/x86_64/mm/init.c.orig	2007-06-07 10:08:04.000000000 +0800
+++ arch/x86_64/mm/init.c	2007-06-18 14:43:15.000000000 +0800
@@ -406,8 +406,7 @@ void __cpuinit zap_low_mappings(int cpu)
 #ifndef CONFIG_NUMA
 void __init paging_init(void)
 {
-	unsigned long max_zone_pfns[MAX_NR_ZONES];
-	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
 	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 	max_zone_pfns[ZONE_NORMAL] = end_pfn;

             reply	other threads:[~2007-06-18 10:12 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-18 10:05 Denis Cheng [this message]
2007-06-18 10:25 ` [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization Robert P. J. Day
2007-06-18 14:24   ` WANG Cong
2007-06-18 17:07 ` Jeremy Fitzhardinge
2007-06-19 13:27   ` Adrian Bunk
2007-06-21 13:21   ` rae l
  -- strict thread matches above, loose matches on Subject: below --
2007-06-23  5:15 Denis Cheng
2007-06-23  7:59 ` Oleg Verych
2007-06-23 13:13   ` Adrian Bunk
2007-06-23 13:41     ` Oleg Verych
2007-06-23 13:57       ` Adrian Bunk
2007-06-23 15:21         ` Segher Boessenkool
2007-06-24 12:58   ` rae l
2007-06-24 22:25     ` Oleg Verych
2007-06-24 22:15       ` Arjan van de Ven
2007-06-24 23:23         ` Benjamin LaHaise
2007-06-25  0:09           ` Arjan van de Ven
2007-06-25  0:12             ` Benjamin LaHaise
2007-06-25  0:23               ` Arjan van de Ven

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