Freebsd 8.0 kmem map too small

[Artem Belevich]

To think of it, UMA on i386 is not such a good idea until we fix ARC
backpressure mechanism. Right now it's rather primitive and  is pretty
much controlled by arc_min. With UMA, it would appear to ZFS that
we're constantly short on memory.

If you're up for another experiment, try raising arc_min to the point
where performance does not degrade much but not that high that it
would cause map too small panic.

--Artem



2010/5/14 Alexander V. Ribchansky <shurik at zk.informjust.ua>:
> 12.05.2010 01:38, Pawel Jakub Dawidek пишет:
>>
>> -skip-
>> Could you try the following patch without disabling UMA?
>>
>> http://people.freebsd.org/~pjd/patches/vfs_subr.c.7.patch
>>
>> It works quite well for me.
>>
>> Also we still don't have back-pressure mechanism when arc_meta_limit is
>> exceeded. OpenSolaris frees namecache entires then and we currently do
>> nothing. I'll experiment with a bit and let you know if the patch above
>> doesn't fix your problem still.
>>
> OOps, I do it again! ;)
> So after several hard days my STABLE gone away again. With your patch and
> UMA enabled. Wired constantly grow, last time I see it, it was about 940M
> As Wired grom, perfomance become terrible, buildworld take about 4 hours on
> Core2quadro.. So my wery IMHO (please don't kill me for it) that UMA
> allocation on i386 is unusable, correct me if I'm wrong.
>
> --
>    AVR39-RIPE
> _______________________________________________
> freebsd-fs at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-fs
> To unsubscribe, send any mail to "freebsd-fs-unsubscribe at freebsd.org"
>