[PATCH] Zero memory more efficiently in mm/percpu.c::pcpu_mem_alloc()

[PATCH] Zero memory more efficiently in mm/percpu.c::pcpu_mem_alloc()

[Jesper Juhl]

Don't do vmalloc() + memset() when vzalloc() will do.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
 percpu.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index efe8168..8d75223 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -294,9 +294,7 @@ static void *pcpu_mem_alloc(size_t size)
 	if (size <= PAGE_SIZE)
 		return kzalloc(size, GFP_KERNEL);
 	else {
-		void *ptr = vmalloc(size);
-		if (ptr)
-			memset(ptr, 0, size);
+		void *ptr = vzalloc(size);
 		return ptr;
 	}
 }


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[PATCH] percpu: zero memory more efficiently in mm/percpu.c::pcpu_mem_alloc()

[Tejun Heo]

Don't do vmalloc() + memset() when vzalloc() will do.

tj: dropped unnecessary temp variable ptr.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
Applied with slight modification.  Thank you.

 mm/percpu.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index efe8168..9e16d1c 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -293,12 +293,8 @@ static void *pcpu_mem_alloc(size_t size)

 	if (size <= PAGE_SIZE)
 		return kzalloc(size, GFP_KERNEL);
-	else {
-		void *ptr = vmalloc(size);
-		if (ptr)
-			memset(ptr, 0, size);
-		return ptr;
-	}
+	else
+		return vzalloc(size);
 }

 /**
-- 
1.7.1

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Re: [PATCH] percpu: zero memory more efficiently in mm/percpu.c::pcpu_mem_alloc()

[Jesper Juhl]

On Sat, 30 Oct 2010, Tejun Heo wrote:

> Don't do vmalloc() + memset() when vzalloc() will do.
> 
> tj: dropped unnecessary temp variable ptr.
> 
I must be needing glasses, I should have seen that initially. Thanks for 
fixing that up :)

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