From: Ricardo Wurmus <rekado@elephly.net>
To: Pjotr Prins <pjotr.public12@thebird.nl>
Cc: guix-devel@gnu.org, Dave Love <fx@gnu.org>
Subject: Re: OpenBLAS and performance
Date: Wed, 20 Dec 2017 19:15:16 +0100 [thread overview]
Message-ID: <87d139xo3v.fsf@elephly.net> (raw)
In-Reply-To: <20171220172215.GA7926@thebird.nl>
Hi Pjotr,
> I was just stating that the default openblas package does not perform
> well (it is single threaded, for one).
Is it really single-threaded? I remember having a couple of problems
with OpenBLAS on our cluster when it is used with Numpy as both would
spawn lots of threads. The solution was to limit OpenBLAS to at most
two threads.
> If I compile for a target it
> makes a large difference.
The FAQ document[1] says this:
The environment variable which control the kernel selection is
OPENBLAS_CORETYPE (see driver/others/dynamic.c) e.g. export
OPENBLAS_CORETYPE=Haswell. And the function char*
openblas_get_corename() returns the used target.
[1]: https://github.com/xianyi/OpenBLAS/wiki/Faq
Have you tried this and compared the performance?
--
Ricardo
GPG: BCA6 89B6 3655 3801 C3C6 2150 197A 5888 235F ACAC
https://elephly.net
next prev parent reply other threads:[~2017-12-20 20:02 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-19 10:49 OpenBLAS and performance Pjotr Prins
2017-12-19 17:12 ` Ludovic Courtès
2017-12-20 11:50 ` Dave Love
2017-12-20 14:48 ` Dave Love
2017-12-20 15:06 ` Ricardo Wurmus
2017-12-22 12:24 ` Dave Love
2017-12-20 17:22 ` Pjotr Prins
2017-12-20 18:15 ` Ricardo Wurmus [this message]
2017-12-20 19:28 ` Pjotr Prins
2017-12-20 20:00 ` Ricardo Wurmus
2017-12-20 20:32 ` Pjotr Prins
2017-12-20 19:02 ` Eric Bavier
2017-12-21 16:38 ` Dave Love
2017-12-20 23:02 ` Ricardo Wurmus
2017-12-21 10:36 ` Pjotr Prins
2017-12-21 14:43 ` Ludovic Courtès
2017-12-22 14:35 ` Dave Love
2017-12-21 16:17 ` Dave Love
2017-12-21 16:46 ` Ricardo Wurmus
2017-12-21 14:55 ` Ludovic Courtès
2017-12-22 12:45 ` Dave Love
2017-12-22 15:10 ` Ludovic Courtès
2017-12-22 16:08 ` Pjotr Prins
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
List information: https://guix.gnu.org/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87d139xo3v.fsf@elephly.net \
--to=rekado@elephly.net \
--cc=fx@gnu.org \
--cc=guix-devel@gnu.org \
--cc=pjotr.public12@thebird.nl \
/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.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/guix.git
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 read-only IMAP folder(s) and NNTP newsgroup(s).