Re: [GIT PULL] Ext3 latency fixes

Jens Axboe
2009-04-06T08:13:58Z

On Sun, Apr 05 2009, Mark Lord wrote:
> Linus Torvalds wrote:
>>
>> Non-rotational media would tend to want the unplugging, but the block
>> layer already does that (ie in __make_request() we already do:
>>
>> if (unplug || blk_queue_nonrot(q))
>> __generic_unplug_device(q);
>>
>> so non-rotational devices get unplugged whether the request was a
>> unplugging request or not).
> ..
>
> Mmm.. except that Jeff's SSD doesn't appear to identify itself
> as a non-rotating media. I suppose there's a way to "quirk" that
> somewhere, though.

You can quirk it in userspace, just have it set the 'rotational' sysfs
file to 0 if it matches make/model/whatever.

--
Jens Axboe