* [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb()
@ 2010-10-30 19:06 Jesper Juhl
2010-11-01 17:55 ` Peter Zijlstra
0 siblings, 1 reply; 4+ messages in thread
From: Jesper Juhl @ 2010-10-30 19:06 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Zijlstra, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin
Hi,
I believe this would be an improvement?
Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb().
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
---
perf_event_amd.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 46d5844..a3787b2 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -280,11 +280,10 @@ static struct amd_nb *amd_alloc_nb(int cpu, int nb_id)
struct amd_nb *nb;
int i;
- nb = kmalloc(sizeof(struct amd_nb), GFP_KERNEL);
+ nb = kzalloc(sizeof(struct amd_nb), GFP_KERNEL);
if (!nb)
return NULL;
- memset(nb, 0, sizeof(*nb));
nb->nb_id = nb_id;
/*
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Plain text mails only, please http://www.expita.com/nomime.html
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb()
2010-10-30 19:06 [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb() Jesper Juhl
@ 2010-11-01 17:55 ` Peter Zijlstra
2010-11-01 17:57 ` Jesper Juhl
0 siblings, 1 reply; 4+ messages in thread
From: Peter Zijlstra @ 2010-11-01 17:55 UTC (permalink / raw)
To: Jesper Juhl
Cc: linux-kernel, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin,
Stephane Eranian, robert.richter, Andreas Herrmann,
Borislav Petkov
On Sat, 2010-10-30 at 21:06 +0200, Jesper Juhl wrote:
> Hi,
>
> I believe this would be an improvement?
>
> Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb().
>
>
> Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> ---
I've changed it to..
---
Subject: perf, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Mon Nov 01 18:52:05 CET 2010
Jasper suggested we use the zeroing capability of the allocators
instead of calling memset ourselves. Add node affinity while we're at
it.
Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
Index: linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event_amd.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event_amd.c
@@ -280,11 +280,10 @@ static struct amd_nb *amd_alloc_nb(int c
struct amd_nb *nb;
int i;
- nb = kmalloc(sizeof(struct amd_nb), GFP_KERNEL);
+ nb = kmalloc_node(sizeof(struct amd_nb), GFP_KERNEL | __GFP_ZERO, nb_id);
if (!nb)
return NULL;
- memset(nb, 0, sizeof(*nb));
nb->nb_id = nb_id;
/*
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb()
2010-11-01 17:55 ` Peter Zijlstra
@ 2010-11-01 17:57 ` Jesper Juhl
2010-11-02 14:08 ` Stephane Eranian
0 siblings, 1 reply; 4+ messages in thread
From: Jesper Juhl @ 2010-11-01 17:57 UTC (permalink / raw)
To: Peter Zijlstra
Cc: linux-kernel, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin,
Stephane Eranian, robert.richter, Andreas Herrmann,
Borislav Petkov
On Mon, 1 Nov 2010, Peter Zijlstra wrote:
> On Sat, 2010-10-30 at 21:06 +0200, Jesper Juhl wrote:
> > Hi,
> >
> > I believe this would be an improvement?
> >
> > Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb().
> >
> >
> > Signed-off-by: Jesper Juhl <jj@chaosbits.net>
> > ---
>
>
> I've changed it to..
>
> ---
> Subject: perf, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation
> From: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Date: Mon Nov 01 18:52:05 CET 2010
>
> Jasper suggested we use the zeroing capability of the allocators
> instead of calling memset ourselves. Add node affinity while we're at
> it.
>
> Reported-by: Jesper Juhl <jj@chaosbits.net>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fine by me.
--
Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/
Plain text mails only, please http://www.expita.com/nomime.html
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb()
2010-11-01 17:57 ` Jesper Juhl
@ 2010-11-02 14:08 ` Stephane Eranian
0 siblings, 0 replies; 4+ messages in thread
From: Stephane Eranian @ 2010-11-02 14:08 UTC (permalink / raw)
To: Jesper Juhl
Cc: Peter Zijlstra, linux-kernel, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin,
robert.richter, Andreas Herrmann, Borislav Petkov
On Mon, Nov 1, 2010 at 6:57 PM, Jesper Juhl <jj@chaosbits.net> wrote:
> On Mon, 1 Nov 2010, Peter Zijlstra wrote:
>
>> On Sat, 2010-10-30 at 21:06 +0200, Jesper Juhl wrote:
>> > Hi,
>> >
>> > I believe this would be an improvement?
>> >
>> > Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb().
>> >
>> >
>> > Signed-off-by: Jesper Juhl <jj@chaosbits.net>
>> > ---
>>
>>
>> I've changed it to..
>>
>> ---
>> Subject: perf, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation
>> From: Peter Zijlstra <a.p.zijlstra@chello.nl>
>> Date: Mon Nov 01 18:52:05 CET 2010
>>
>> Jasper suggested we use the zeroing capability of the allocators
>> instead of calling memset ourselves. Add node affinity while we're at
>> it.
>>
>> Reported-by: Jesper Juhl <jj@chaosbits.net>
>> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
>
> Fine by me.
>
Works for me.
Acked-by: Stephane Eranian <eranian@google.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-11-02 14:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2010-10-30 19:06 [PATCH] Perf, AMD: Prefer kzalloc() over kmalloc()+memset() in amd_alloc_nb() Jesper Juhl
2010-11-01 17:55 ` Peter Zijlstra
2010-11-01 17:57 ` Jesper Juhl
2010-11-02 14:08 ` Stephane Eranian
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