Re: Re: [PATCH 2/2] raid5: For write performance, remove REQ_SYNC when write was odirect.

[majianpeng <majianpeng@xxxxxxxxx>]

On 2012-07-16 15:07 NeilBrown <neilb@xxxxxxx> Wrote:
>On Mon, 16 Jul 2012 14:42:54 +0800 majianpeng <majianpeng@xxxxxxxxx> wrote:
>
>> On 2012-07-16 13:40 NeilBrown <neilb@xxxxxxx> Wrote:
>> >On Mon, 16 Jul 2012 09:31:55 +0800 majianpeng <majianpeng@xxxxxxxxx> wrote:
>> >
[snip]
>> > Normal 'sync' requests use WRITE_SYNC which includes "REQ_NOIDLE" which means
>> >   /* don't anticipate more IO after this one */
>> > O_DIRECT request use WRITE_ODIRECT which does not include this flag.
>> >
>
>> Using REQ_NOIDEL to difference odirect and sync.Why not using:
>>  +	if (bi->bi_rw & WRITE_ODIRECT)
>>  +		bi->bi_rw &= ~REQ_SYNC;
>
>Because that code is wrong.  WRITE_ODIRECT is not one flag, it is two flags
>'or'ed together.  So this code does not do what you expect.
>
No, I used those code test and it's ok.
The code used & not &&.
Maybe I wrong?
>
>> 
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