is TMPFS still highly experimental?

[krad]

On 2 October 2011 07:41, Chris Rees <crees at freebsd.org> wrote:

> On 2 Oct 2011 03:03, "Jeremy Chadwick" <freebsd at jdc.parodius.com> wrote:
> >
> > On Sat, Oct 01, 2011 at 06:02:39PM -0700, Xin LI wrote:
> > > On Sat, Oct 1, 2011 at 8:48 AM, Chris Rees <crees at freebsd.org> wrote:
> > > > I've also not heard of anyone using it with zfs successfully- it
> tends
> to
> > > > shrink rapidly.
> > >
> > > I'm quite surprised with this assertion.  I use tmpfs on my own system
> > > and I never see such problem as long as one have sufficient swap
> > > space.
> > >
> > > Not to say there is no problem --there is no way to say "commit this
> > > amount of memory to ZFS" but really I have never hit this exact
> > > alleged problem...
> >
> > Its been reported multiple times by multiple people, and there has been
> > no official word on -fs, -stable, or zfs-devel that this specific
> > problem has been fixed:
> >
> > * miyamoto moesasji
> >  - 2011/01/01
> >  - 8.2-PRERELEASE (thus RELENG_8)
> >  - World/kernel build date unknown
> >  -
> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/060850.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/060852.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/060860.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/060861.html
> >  - Statement from Ivan Voras that it's a known problem:
> >  -
> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/060867.html
> >
> > * Atilla Nagy
> >  - 2011/01/19
> >  - 8.2-PRERELEASE (thus RELENG_8)
> >  - World/kernel build date of 2011/01/08
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010496.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010497.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010498.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010499.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010501.html
> >  -
> http://lists.freebsd.org/pipermail/freebsd-fs/2011-January/010569.html
> >  - Ivan Voras mentions a thread he started on -CURRENT circa 2010/11/21
> >    about this problem:
> >
> http://www.mail-archive.com/freebsd-current@freebsd.org/msg126491.html
> >
> > * Michael Loftis
> >  - 2009/12/08
> >  - FreeBSD 8.0-RELEASE (RELENG_8_0)
> >  - World/kernel build date of 2009/11/21
> >  - Might be a different problem altogether, but tmpfs is explicitly
> >    mentioned in the fix/commit text from avg@
> >  - http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/141305
> >
> > Plus Chris Rees' report.  So that makes 3, possibly 4 if you consider
> > the PR from Michael Loftis.
> >
> > Possibly it has something to do with the exact FreeBSD version they're
> > using.  Not just version (e.g. 8.2-RELEASE vs. 8.2-STABLE), but also
> > kernel/world build date -- because as we've established, ZFS changes are
> > happening all the time and there is very little transparency when it
> > comes to communicating these changes to the community.
> >
> > Maybe the problem has been fixed in RELENG_8 sometime after 2011/01/08,
> > but we do not know.  ZFS committers would need to help.  Else, folks
> > should be reaching out to the first two people I mentioned above and
> > asking if they can reproduce the problem on present-day RELENG_8.
> >
>
> Thanks hugely for doing the linking and research I should have done-- I've
> not personally had these problems but I recalled the recent conversation,
> that's all.
>
> Chris
> _______________________________________________
> 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"
>


It may seem a silly question, but I have been wondering about tmpfs and zfs,
and whether there is any point to mixing the two?

Surely if you have frequently accessed files under /tmp they are going to be
in the arc or l2arc anyway so fairly speedy, or am I missing the point of
tmpfs?