From: Dave Chinner <david@fromorbit.com>
To: cluster-devel.redhat.com
Subject: [Cluster-devel] [PATCH] gfs2: use __vmalloc GFP_NOFS for fs-related allocations.
Date: Thu, 5 Feb 2015 22:45:00 +1100 [thread overview]
Message-ID: <20150205114459.GI12722@dastard> (raw)
In-Reply-To: <BD2045CE-45AD-4D79-8C8D-C854D112DCC5@linuxhacker.ru>
On Wed, Feb 04, 2015 at 02:13:29AM -0500, Oleg Drokin wrote:
> Hello!
>
> On Feb 3, 2015, at 5:33 PM, Dave Chinner wrote:
> >> I also wonder if vmalloc is still very slow? That was the case some
> >> time ago when I noticed a problem in directory access times in gfs2,
> >> which made us change to use kmalloc with a vmalloc fallback in the
> >> first place,
> > Another of the "myths" about vmalloc. The speed and scalability of
> > vmap/vmalloc is a long solved problem - Nick Piggin fixed the worst
> > of those problems 5-6 years ago - see the rewrite from 2008 that
> > started with commit db64fe0 ("mm: rewrite vmap layer")....
>
> This actually might be less true than one would hope. At least somewhat
> recent studies by LLNL (https://jira.hpdd.intel.com/browse/LU-4008)
> show that there's huge contention on vmlist_lock, so if you have vmalloc
vmlist_lock and the list it protected went away in 3.10.
Cheers,
Dave.
--
Dave Chinner
david at fromorbit.com
prev parent reply other threads:[~2015-02-05 11:45 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-02 3:59 [Cluster-devel] [PATCH] gfs2: use __vmalloc GFP_NOFS for fs-related allocations green
2015-02-02 5:37 ` Dave Chinner
2015-02-02 6:57 ` Oleg Drokin
2015-02-02 8:11 ` Dave Chinner
2015-02-02 10:30 ` Steven Whitehouse
2015-02-03 22:33 ` Dave Chinner
2015-02-04 7:13 ` Oleg Drokin
2015-02-04 9:49 ` Steven Whitehouse
2015-02-05 20:11 ` Dave Chinner
2015-02-05 11:45 ` Dave Chinner [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150205114459.GI12722@dastard \
--to=david@fromorbit.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).