RELENG_4 -> 5 -> 6: significant performance regression

ml at sd2i.com ml at sd2i.com
Thu Apr 27 19:17:31 UTC 2006


Kris Kennaway a écrit :
> On Thu, Apr 27, 2006 at 08:26:06PM +0200, ml at sd2i.com wrote:
>> Kris Kennaway a ?crit :
>>> On Thu, Apr 27, 2006 at 05:08:11PM +0300, Dmitry Pryanishnikov wrote:
>>>
>>>
>>>> options 	QUOTA
>>> This definitely effects performance on 6.x since it makes your
>>> filesystem giant-locked, which may also interfere with your network
>>> processing.
>> Why would QUOTA affect performance more on 6.x than 4.x ? I would like 
>> to understand because i think a system cannot be secure without QUOTA
> 
> It makes filesystem writes acquire Giant, which blocks other kernel
> code that needs to also acquire Giant.  When the need to acquire Giant
> was removed from the mainstream UFS code in 6.0 it was an enormous
> performance improvement.

Thanks for your anwser, but i'm not sure i understand... You wrote that 
Giant is needed in 6.0 and now you write it has been removed.

So is it removed for 6-STABLE ? 6.1-rc ? Since i already use 6.x boxes, 
and i do have performance issues, i would upgrade to the right version 
immediatly

R.


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