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

From: Ingo Molnar
Date: Thu Apr 16 2015 - 03:28:17 EST



* 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.

Thanks,

Ingo
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