status of autotuning freebsd for 9.2

[Dewayne Geraghty]

> -----Original Message-----
> From: owner-freebsd-stable at freebsd.org 
> [mailto:owner-freebsd-stable at freebsd.org] On Behalf Of Alfred 
> Perlstein
> Sent: Tuesday, 20 August 2013 2:05 AM
> To: Outback Dingo
> Cc: re at freebsd.org; stable at freebsd.org; Andre Oppermann; 
> nonesuch at longcount.org
> Subject: Re: status of autotuning freebsd for 9.2
> 
> Performance is bad for large memory requirements period. 
> 
> Vnodes and mbufs on a machine with 24gb ram is limited to the 
> same amount as a machine with less than 4GB ram. 
> 
> This was fixed in head but not merged back in time. 
> 
> This results in poor out of the box performance on 10gige and 
> servers with high vnode requirements.  
> 
> Sent from my iPhone
> 
> On Aug 19, 2013, at 7:30 AM, Outback Dingo 
> <outbackdingo at gmail.com> wrote:
> 
> > 
> > 
> > 
> > On Mon, Aug 19, 2013 at 10:26 AM, Alfred Perlstein 
> <alfred at ixsystems.com> wrote:
> >> 
> >> 
> >> On Aug 19, 2013, at 2:52 AM, Andre Oppermann 
> <andre at freebsd.org> wrote:
> >> 
> >> > On 16.08.2013 10:29, Andre Oppermann wrote:
> >> >> On 16.08.2013 08:32, Alfred Perlstein wrote:
> >> >>> Andre, I'm kind of bummed out this didn't make it into 
> 9.2, I'm 
> >> >>> wondering can I commit this to 9-stable now?  (or is 
> it already 
> >> >>> in?)
> >> >>
> >> >> It didn't make it because there was only sparse 
> feedback after the 
> >> >> call for testers.  There were a couple of replies that 
> it is being 
> >> >> tested but no statements either way if it was good or 
> not.  Hence 
> >> >> I erred on the side of caution and refrained from committing it.
> >> >
> >> > Revisiting the history of this after vacation absence actually 
> >> > shows that we straddled the release code freeze deadline and you 
> >> > had provided good testing feedback.  However the MFC got 
> rejected 
> >> > by RE on the fear of introducing unknown regressions 
> into the release process.
> >> >
> >> >>> Would you do the honors?
> >> >>
> >> >> Yes, will do later today.
> >> >
> >> > Committed to stable/9 as r254515.
> >> >
> >> > Let me know if there are any issues.
> >> 
> >> Thanks Andre.
> >> 
> >>  Maybe we can do a point release/patch release with this 
> in a few weeks for 9.2.1 or 9.2p1 because 9.2 out of the box 
> performance is abysmal not only in networking but also disk 
> as maxvnodes is clipped way too small even with plenty of ram.
> > 
> > So your saying, 9.2-RELEASE performance suffers degradation against 
> > say 9.1 ?? are you referring to with this patch enabled? or just in 
> > general 9.2-RELEASE
> >  
> >> >
> >> > --
> >> > Andre
> >> >
> >> _______________________________________________
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> > 
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It might be relevant that there were performance changes to nullfs (caching) code back in January and updated in May by Kib. Because
I use jails and nullfs extensively, the nullfs enhancement demanded an increase in maxvodes, otherwise performance degraded, quite
badly.  Tripling the default suited my needs on 4GB systems, but I don't have an algorithmic recommendation; as for me it depends on
the role/purpose of the server.  

If vnodes is an issue *and* you use mount_nullfs, another approach is to disable caching via 
"mount_nullfs -o nocache" as this may help to narrow the cause.

Ref:
http://svnweb.freebsd.org/base/stable/9/sys/fs/nullfs/null_subr.c?view=log
http://lists.freebsd.org/pipermail/svn-src-stable-9/2013-May/004531.html

And thank-you for your work on http://lists.freebsd.org/pipermail/svn-src-stable-9/2013-August/005307.html

Regards, Dewayne.