lkml.org 
[lkml]   [2009]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/4] block: use the same failfast bits for bio and request
On Thu, Jul 09 2009, Jeff Garzik wrote:
> Christoph Hellwig wrote:
>> On Thu, Jul 09, 2009 at 09:45:24AM +0900, Tejun Heo wrote:
>>> What's more disturbing to me is the different between RQ and BIO
>>> flags. __REQ_* are bit positions, REQ_* are masks while BIO_* are bit
>>> positions. Sadly it seems it's already too late to change that. I
>>> personally an not a big fan of simple accessors or flags defined as
>>> bit positions. They seem to obscure things without much benefit.
>>
>> flags as bit positions generally only make sense if you use
>> test/set/clear_bit, otherwise they just confuse things. And the
>> accessors are pretty annoying, especially in the block layer. Trying to
>> find the places where a BIO flag has an actual effect is pretty painful
>> due to the mix of the different flags and the accessors.
>
> Indeed -- the accessors mean in practice that you always have at least
> _two_ things to grep for, just to catch all accesses. Block layer is
> pretty bad about that style of usage :/

Yeah, I'm not too fond of it either, it does add to the confusion. I'll
sanitize it.

--
Jens Axboe



\
 
 \ /
  Last update: 2009-07-09 19:41    [W:0.067 / U:0.432 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site