ufs multilabel performance (fwd)

Edward Tomasz Napierała trasz at FreeBSD.org
Tue Apr 17 20:57:15 UTC 2012


Wiadomość napisana przez Adrian Chadd w dniu 17 kwi 2012, o godz. 21:17:
> On 16 April 2012 23:31, Richard Kojedzinszky <krichy at tvnetwork.hu> wrote:
>> 
>> So now reactions here, creating files with multilabel is still slow.
>> 
>> I would like to use multilabel access control on my /tmp, for example, my
>> web server places it's session files there in a subdirectory. Of course, I
>> would like to assign a label for that subdir, but with this slow file
>> creation, that is not the way to go. I may then use a different filesystem
>> for that. In this case, can I assign a root mac label for a mount point?
> 
> Hi,
> 
> This is a perfect job for hwpmc / dtrace.
> 
> Would you be able to load up either of those and get some CPU usage
> statistics whilst you're running your benchmark?
> 
> It's either that, or it's (massive) locking contention.

Or disk I/O.  MAC labels, just like ACLs, are stored in extended attributes,
and I remember something about writing those being synchronous.

-- 
If you cut off my head, what would I say?  Me and my head, or me and my body?



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