Re: [PATCH] kernel/softirq.c: delete 'while' looping to improve alittle performance and beautify code
From: Chen Gang
Date: Wed Jun 12 2013 - 22:11:26 EST
On 06/10/2013 10:15 PM, Thomas Gleixner wrote:
> On Sun, 9 Jun 2013, Chen Gang wrote:
>> > After finish the internal 'while', need not test TASKLET_STATE_SCHED
>> > again, so looping back to outside 'while' is only for set_bit().
>> >
>> > When use 'if' and set_bit() instead of 'while', it will save at least
>> > one running conditional instruction, and also will be clearer for readers
>> > (although the binary size will be a little bigger).
> And by doing that you break the atomicity of test_and_set_bit. There
> is a good reason why this is an atomic operation and why the code is
> written as is.
>
OK, thanks. it is my fault (and also sorry for replying late).
>> > The related patch is "1da177e Linux-2.6.12-rc2"
> How is that patch related to the problem?
Because the modification since Linux-2.6.12-rc2.
Thanks.
--
Chen Gang
Asianux Corporation
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