[PATCH] cgroup: prefer [kv]zalloc over [kv]malloc+memset in memory controller code.
minchan.kim at gmail.com
Mon Nov 1 16:21:43 PDT 2010
On Tue, Nov 2, 2010 at 4:59 AM, Jesper Juhl <jj at chaosbits.net> wrote:
> On Mon, 1 Nov 2010, Johannes Weiner wrote:
>> On Mon, Nov 01, 2010 at 08:40:56PM +0100, Jesper Juhl wrote:
>> > Hi (please CC me on replies),
>> > Apologies to those who receive this multiple times. I screwed up the To:
>> > field in my original mail :-(
>> > In mem_cgroup_alloc() we currently do either kmalloc() or vmalloc() then
>> > followed by memset() to zero the memory. This can be more efficiently
>> > achieved by using kzalloc() and vzalloc().
>> > Signed-off-by: Jesper Juhl <jj at chaosbits.net>
>> Looks good to me, but there is also the memset after kmalloc in
> Dang, I missed that one. Thanks for pointing it out.
> Hmm, I'm wondering if we should perhaps add kzalloc_node()/vzalloc_node()
> just like kzalloc() and vzalloc()..
I am not against that.
As looking code, there are many places to use kzalloc_node but few vzalloc_node.
Although it is, Only adding kzalloc_node would make code rather ugly like this.
if (some size > limit)
ptr = kzalloc_node(...);
prt = vmalloc_node(...)
vmalloced = 1;
if (ptr && vmalloced)
So if we will add kzalloc_node, we have to add vzalloc_node, too.
>> Can you switch that over as well in
>> this patch? You can pass __GFP_ZERO to kmalloc_node() for zeroing.
> Sure thing.
> Signed-off-by: Jesper Juhl <jj at chaosbits.net>
Reviewed-by: Minchan Kim <minchan.kim at gmail.com>
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