[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Thu, 07 Jul 2011 04:52:34 -0700 (PDT)
From: David Miller <davem@...emloft.net>
To: abbotti@....co.uk
Cc: ian.abbott@....co.uk, netdev@...r.kernel.org, arnd@...db.de,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] lib/checksum.c: optimize do_csum a bit
From: David Miller <davem@...emloft.net>
Date: Thu, 07 Jul 2011 04:36:25 -0700 (PDT)
> From: Ian Abbott <abbotti@....co.uk>
> Date: Thu, 7 Jul 2011 12:32:45 +0100
>
>> On 07/07/11 12:29, David Miller wrote:
>>> From: Ian Abbott <abbotti@....co.uk>
>>> Date: Thu, 7 Jul 2011 12:18:49 +0100
>>>
>>>> Reduce the number of variables modified by the loop in do_csum() by 1,
>>>> which seems like a good idea. On Nios II (a RISC CPU with 3-operand
>>>> instruction set) it reduces the loop from 7 to 6 instructions, including
>>>> the conditional branch.
>>>>
>>>> Signed-off-by: Ian Abbott <abbotti@....co.uk>
>>>
>>> I think you'll overshoot past the end of the buffer when there are
>>> trailing bytes to handle.
>>>
>>> The whole reason we need the count variable is to handle those
>>> kinds of cases.
>>
>> I don't think it does. That's what the & ~3 was for.
>
> Aha, yes that indeed makes it work.
I've applied this to net-next-2.6, thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists