Re: [PATCH] x86: Enable fast 32-bit put_user_64 for copy_to_user

From: Chris Wilson
Date: Thu Apr 16 2015 - 03:41:06 EST


On Thu, Apr 16, 2015 at 09:28:02AM +0200, Ingo Molnar wrote:
>
> * Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
>
> > For fixed sized copies, copy_to_user() will utilize __put_user_size
> > fastpaths. However, it is missing the translation for 64bit copies on
> > x86/32. Testing on a Pinetrail Atom, the 64 bit put_user fastpath is
> > substantially faster than the generic copy_to_user() fallback.
> >
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> > Cc: x86@xxxxxxxxxx
> > CC: linux-kernel@xxxxxxxxxxxxxxx
>
> The patch makes sense, but your Signed-off-by line is missing.

Sorry, totally forgot that when rewriting the changelog.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
-Chris

--
Chris Wilson, Intel Open Source Technology Centre
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