Re: [PATCH] mtd/nand: use string library

From: Brian Norris
Date: Fri Jan 27 2012 - 13:52:49 EST


On Fri, Jan 27, 2012 at 9:16 AM, Joe Perches <joe@xxxxxxxxxxx> wrote:
> On Fri, 2012-01-27 at 23:24 +0900, Akinobu Mita wrote:
>> - Use memchr_inv to check if the data contains all 0xFF bytes.
>>   It is faster than looping for each byte.
>
> Stupid question:
>
> Are there any mtd devices modified that are slower
> at 64 bit accesses than repeated 8 bit accesses?

I believe this patch deals with kernel buffers, not any kind of direct
access to the MTD, so the question (which is not stupid IMO) should be
regarding CPU architectures. And my educated guess is that 64-bit
access should not be any slower. I do know that 8-bit access *is*
slower for some relevant architectures.

Brian
--
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/