Re: [PATCH] bio: skip atomic inc/dec of ->bi_remaining for non-chains

[Jens Axboe <axboe@fb.com>]

On 04/20/2015 10:04 AM, Jan Kara wrote:
> On Fri 17-04-15 08:59:33, Jens Axboe wrote:
>> @@ -292,8 +292,8 @@ void bio_reset(struct bio *bio)
>>   	__bio_free(bio);
>>
>>   	memset(bio, 0, BIO_RESET_BYTES);
>> -	bio->bi_flags = flags|(1 << BIO_UPTODATE);
>> -	atomic_set(&bio->bi_remaining, 1);
>> +	bio->bi_flags = flags | 1 << BIO_UPTODATE;
>    Although this is correct, I'd prefer to keep parenthesis around 1 <<
> BIO_UPTODATE. Maybe I'm not a real C hacker but I had to lookup the
> operator precedence of | vs << :).

Heh, I think we can safely say you are a real C hacker, lets just keep 
the parenthesis if that makes it easier to read/verify.

> Otherwise the patch looks good to me (but I'm not an expert in this area, I
> just looked into the patch by accident because I thought it's another
> respin of your direct IO patch ;).

It's a parallel effort, getting rid of the atomics where we can... 
Thanks for looking at it, can I add your reviewed-by tag with the 
parenthesis change?

-- 
Jens Axboe