Skip to Content.
Sympa Menu

charm - [charm] Question about oversubscription

charm AT lists.cs.illinois.edu

Subject: Charm++ parallel programming system

List archive

[charm] Question about oversubscription


Chronological Thread 
  • From: Maksym Planeta <mplaneta AT os.inf.tu-dresden.de>
  • To: charm <charm AT lists.cs.illinois.edu>
  • Subject: [charm] Question about oversubscription
  • Date: Thu, 10 Nov 2016 16:46:13 +0100

Dear Charm++ group,

as far as I understand, the main mode of operation of AMPI is running it in oversubscribed mode.

Does it mean that I should create less processes (+p parameter), than I have cores? And I should create at least as many virtual processes (+vp) as I have cores, or even more?

I tried to create 64 processes on 8 nodes and specified +vp 512. What I observed is that at each node there were 8 processes created, and the rest 16 cores of each 24-cores node stayed unoccupied. Did I do something wrong?

The way how I launched the program is following:

./charmrun +p64 ++mpiexec ++remote-shell $HOME/script.sh ./lulesh2.0 +vp512 -i 300

The script basically only does "exec srun -N 8 -n $*"

--
Regards,
Maksym Planeta

Attachment: smime.p7s
Description: S/MIME Cryptographic Signature




Archive powered by MHonArc 2.6.19.

Top of Page