Re: [PATCH]micro optimization of kcalloc

From: David Lang
Date: Mon Mar 20 2006 - 13:49:11 EST


On Mon, 20 Mar 2006, Pekka Enberg wrote:

Hi,

On Mon, Mar 20, 2006 at 03:45:23PM +0100, Oliver Neukum wrote:
static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
{
- if (n != 0 && size > INT_MAX / n)
+ if (unlikely(size != 0 && n > INT_MAX / size ))
return NULL;
return kzalloc(n * size, flags);
}

On 3/20/06, Benjamin LaHaise <bcrl@xxxxxxxxx> wrote:
This function shouldn't be inlined. We have no need to optimize the
unlikely case like this.

IIRC, I made it static inline in the first place because that actually
reduced kernel text size. (And I think it was Adrian who made me do it
:-).

I wonder if this is still needed with the new inline changes that were made to allow GCC to make the decision (for recent GCC's)

David Lang

--
There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies.
-- C.A.R. Hoare

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