Re: SSD slowdown with 3.3.X?

[Mark Lord <kernel@teksavvy.com>]

On 12-04-21 02:30 PM, Stan Hoeppner wrote:
> On 4/21/2012 6:45 AM, cwillu wrote:
>>> Probably not relevant in this case but maybe worth mentioning to get the
>>> word out:
>>>
>>> "As of kernel 3.2.12, the default i/o scheduler, CFQ, will defeat much
>>> of the parallelization in XFS."
>>>
>>> http://www.xfs.org/index.php/XFS_FAQ
>>
>> Not that it's terribly relevant to btrfs, but do you have a better
>> citation for that than a very recent one-line wiki change that only
>> cites the user's own anecdote?
> 
> Apologies for the rather weak citation.  It was simply easier to quote
> that wiki entry.
> 
> How about something directly from Dave's fingers:
> http://www.spinics.net/lists/xfs/msg10824.html
> 
> The many issues with CFQ+XFS didn't start with 3.2.12, but long before that.


Thanks for the link.  That's handy to know.

The problems there are for XFS+RAID vs. CFQ, not XFS by itself.
Enterprise servers will normally have RAID under XFS,
but not all smaller systems.

Cheers