Re: Linux I/O stack design question

[Jens Axboe <axboe@xxxxxxxxx>]

On 2011-09-05 16:01, Werner Fischer wrote:
> On Don, 2011-09-01 at 15:13 -0600, Jens Axboe wrote:
>> [...]
>> I mean that every device should plug in at the same place. There are
>> definite up and down sides to plugging in at the stacking level and
>> bypassing the IO scheduler. So you have to weight the pros and cons
>> before doing that. We need to fix this. Drivers doing that lose out on
>> other features in the name of a bit more performance, that's just not
>> acceptable.
> 
> I have updated the diagram according to all of your hints:
> http://www.thomas-krenn.com/de/wikiDE/images/0/07/Linux-IO-Stack.png
> 
> I had also some off-list discussion with Florian Haas, who convinced me
> that the file systems are below of the page cache. I hope this is now
> correct.

Not sure I'd agree with that, I'd place the page cache between the fs
and the storage layer.

-- 
Jens Axboe

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