Re: [PATCH] x86: introduce and use percpu_inc()

From: H. Peter Anvin
Date: Thu Apr 22 2010 - 02:48:38 EST


On 04/21/2010 11:26 PM, Jan Beulich wrote:
>
>> Keep in mind that although INC is smaller than ADD,
>> the former has flag dependencies that the latter doesn't...
>
> Wasn't that a problem just on Pentium4-s, which when I submitted
> another related patch a couple of months back I was told would
> not be a primary target anymore?
>

It doesn't look like it, from what I could tell after the abovementioned
conversation... I was wondering mostly how many bytes this saved across
the kernel. If it saves a byte in one place it's not so interesting,
but if it is all over it might make more sense.

It bit much worse on P4 than on most other cores, though.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/