Re: [PATCH] libata: implement ata_qc_exec_internal()

[Tejun Heo <htejun@gmail.com>]

Tejun Heo wrote:
> Tejun Heo wrote:
> 
>> Raz Ben-Jehuda(caro) wrote:
>>
>>> does it solve the cpu usage ?
>>>
>>> On 11/28/05, Tejun Heo <htejun@gmail.com> wrote:
>>>
>>>> Each user libata internal commands initializes a qc, issues it, waits
>>>> for its completion and checks for errors.  This patch factors internal
>>>> command execution sequence into ata_qc_exec_internal().  The function
>>>> also removes race condition between irq and timeout handling.
>>>>
>>>> Signed-off-by: Tejun Heo <htejun@gmail.com>
>>>>
>>
>> Hi, Raz.
>>
>> It propabably has nothing to do with the cpu usage problem on piix you 
>> reported.  I think you need to post more data to get people on the 
>> list interested in your problem.  The followings may help.
>>
>> 1. Please report exactly which kernel you're using and more 
>> information on the hardware will also help.
>>
>> 2. Don't use raid or any fs on it.  Just perform tests on raw /dev/sdx 
>> devices.  Do something like 'time dd if=/dev/sdx of=/dev/zero bs=1M 
>> count=1024' and report how much user/system time it uses.
> 
> 
> Oops, count=1024 is way too small.  Do something like bs=1M count=1M or 
> maybe count=10M.

I hate myself.  I must be on crack or something now.  count=1024 should 
be fine (count=2k or 4k should be fine too).  Don't do count=1M or 10M.

Sorry guys.  :-)

-- 
tejun