Valerie Henson wrote:
Hello all,
We are doing some work on large page support in Linux.
Yes, Yes, YES !!!
Please reply directly to me, unless you have something to share with
the whole list. Thanks!
Arggghhhh - you can't be serious.
1. What does your organization do?
My day time job (i.e., when I'm *not* working on GNU Fortran) at the
Dutch Weather Service entails improving our Limited Area Numerical
Weather Forecasting Model - hirlam.org).
2. What does your application do?
Forecasts the weather up to 48 hours in advance over the Atlantic +
Europe (at least, that's the default configuration).
3. How are large pages useful to you?
We use lots and lots of memory every time step in the model. Our
soon-to-be operational model uses ~ 1 Gbyte of memory per (~100) MPI
node every time step. There are 720 time steps (48 hours * 15 time
steps of 4 minutes real time per hour) during the 40 minute integration.
The job maximum time of 40 minutes is determined by our delivery dead
line.
4. What is your experience with the Linux hugetlbfs implementation of
large page support?
Haven't tried it yet. However, our experience on Solaris 9 (which
supports 4 Mbyte pages down to the compilation/link unit) is very
positive (this is on UltraSPARC III hardware).
5. Does Linux's large page support affect your decision whether or not
to use Linux? If so, how?
Nope. We bought a Linux solution because hw+sw+other stuff was better
this way (SGI Altix).
6. What would make large page support in Linux better for your application?
Duh. Fewer TLB cache reloads.
Cheers,
--
Toon Moene - e-mail: [EMAIL PROTECTED] - phone: +31 346 214290
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
A maintainer of GNU Fortran 95: http://gcc.gnu.org/fortran/
Gfortran At Work: http://mysite.verizon.net/serveall/moene.pdf
_______________________________________________
Beowulf mailing list, Beowulf@beowulf.org
To change your subscription (digest mode or unsubscribe) visit
http://www.beowulf.org/mailman/listinfo/beowulf
