From: Sylvain Le Gall <sylvain@le-gall.net>
To: caml-list@inria.fr
Subject: Re: ocamlmpi reduce_int_array, showstopper?
Date: Mon, 6 Sep 2010 10:51:37 +0000 (UTC) [thread overview]
Message-ID: <slrni89htp.skq.sylvain@gallu.homelinux.org> (raw)
In-Reply-To: <AANLkTimEra9gdaJRz4nwrRfMrz-VovAQLB7vPuN9fK9G@mail.gmail.com>
On 04-09-2010, Mike Lin <mikelin@MIT.EDU> wrote:
> Hi Sylvain, Xavier,
> I have encountered what seems to be a serious problem with
> reduce_int_array in ocamlmpi, namely, in a trivial test case it
> successfully returns incorrect results. This is my test code
>
[...]
>
> [mikelin@honest3 ~/]$ uname -a
> Linux honest3.ncsa.uiuc.edu 2.6.18-92.1.10.el5_lustre.1.6.6smp-perfctr
> #7 SMP Tue Nov 10 10:41:00 CST 2009 x86_64 x86_64 x86_64 GNU/Linux
> [mikelin@honest3 ~/]$ which mpiexec
> /usr/local/mvapich2-1.2-intel-ofed-1.2.5.5/bin/mpiexec
>
> see also: http://www.ncsa.illinois.edu/UserInfo/Resources/Hardware/Intel64Cluster/
>
> I know the ocamlmpi code has been stable for some time, but I wonder
> if it's been tested on x86_64? Let me know if you're able to reproduce
> this.
>
I can confirm the bug. I have commited a fix in the svn. Though, I am
not an MPI expert.
I think the problem was related to a double in-place re-encoding of
integer in the array. I'll wait for Xavier review to do a release.
Regards,
Sylvain Le Gall
prev parent reply other threads:[~2010-09-06 10:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-04 18:25 Mike Lin
2010-09-06 10:51 ` Sylvain Le Gall [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=slrni89htp.skq.sylvain@gallu.homelinux.org \
--to=sylvain@le-gall.net \
--cc=caml-list@inria.fr \
/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).