Hi Rick –
Have you added the tmem parameter in the Xen boot line in dom0 (e.g.
the line in grub.conf with xen.gz)? Tmem is not enabled by default in the
official 4.0 release bits. Note that you must also explicitly provide the
tmem_compress parameter and (if using 4.0.1-rc) tmem_dedup on the Xen boot line
if you want that functionality turned on in tmem.
Also, what guest kernels are you using? I now have a fully
built alternate kernel rpm for EL5u5 at: http://oss.oracle.com/projects/tmem/files/oel5u5/
(And
look at the README that is there.) If you are not using EL5u5, but you are
familiar with src rpms and building your own kernel, the tmem patch there is
the most recent for a 2.6.18-based kernel and has full in-kernel self-ballooning
builtin. And if you are using a 2.6.32-based kernel, the sister directory
for RHEL6beta has the same (and also a README). Note that for these recent
tmem Linux patches, tmem must also be given as a boot parameter to the guest
kernel in the guest grub.conf.
Sorry that the tmem “user” documentation is not very up to date.
I’ve been focused on making tmem easier to use via pre-built rpm’s
and also pushing it upstream into Linux, both of which have resulted in linux
patch (and some use-model) changes. In the meantime, I’d be happy
to work directly with you (onlist or offlist) to help you get tmem running in
your environment.
Thanks,
Dan
P.S. The terms “precache” and “preswap”
are now obsolete as the Linux community dissed them as too generic. I have
renamed them “cleancache” and “frontswap”. See http://lwn.net/Articles/386090/
But, yes I know, much tmem documentation still has the old names
and I need to change those docs.
From: Rick Boone
[mailto:rick@xxxxxxxxxxxxxx]
Sent: Wednesday, July 14, 2010 2:20 PM
To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] Basics on TMEM usage/setup?
Hey,
I can't seem to find any general guidelines/FAQ's/docs for using TMEM in xen
4.0. I've built the kernel with the tmem config options (tmem, precache,
preswap), but whenever I run "xm tmem-list -a", I get a
"-1" response. Feels like I might have missed something - any info
out there?
-- Rick
