diff options
author | Peter Zijlstra <peterz@infradead.org> | 2013-01-22 02:39:13 -0500 |
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committer | Gleb Natapov <gleb@redhat.com> | 2013-01-29 08:38:37 -0500 |
commit | 7b270f609982f68f2433442bf167f735e7364b06 (patch) | |
tree | 07430a425125c1938fad3befc6debec667310ec4 /virt | |
parent | c7c9c56ca26f7b9458711b2d78b60b60e0d38ba7 (diff) |
sched: Bail out of yield_to when source and target runqueue has one task
In case of undercomitted scenarios, especially in large guests
yield_to overhead is significantly high. when run queue length of
source and target is one, take an opportunity to bail out and return
-ESRCH. This return condition can be further exploited to quickly come
out of PLE handler.
(History: Raghavendra initially worked on break out of kvm ple handler upon
seeing source runqueue length = 1, but it had to export rq length).
Peter came up with the elegant idea of return -ESRCH in scheduler core.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Raghavendra, Checking the rq length of target vcpu condition added.(thanks Avi)
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Andrew Jones <drjones@redhat.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions