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Subject: [OMPI users] High CPU usage with yield_when_idle =1 on CFS
From: Randolph Pullen (randolph_pullen_at_[hidden])
Date: 2011-09-01 02:48:09


I recall a discussion some time ago about yield, the Completely F%’d Scheduler (CFS) and OpenMPI. My system is currently suffering from massive CPU use while busy waiting.  This gets worse as I try to bump up user concurrency. I am running with yield_when_idle but its not enough. Is there anything else I can do to release some CPU resource? I recall seeing one post where usleep(1) was inserted around the yields, is this still feasible? I'm using 1.4.1 - is there a fix to be found in upgrading? Unfortunately I am stuck  with the CFS as I need Linux.  Currently its Ubuntu 10.10 with 2.6.32.14 Thanks in advance