sched: make double-lock-balance fair

Browse source

double_lock balance() currently favors logically lower cpus since they
often do not have to release their own lock to acquire a second lock.
The result is that logically higher cpus can get starved when there is
a lot of pressure on the RQs.  This can result in higher latencies on
higher cpu-ids.

This patch makes the algorithm more fair by forcing all paths to have
to release both locks before acquiring them again.  Since callsites to
double_lock_balance already consider it a potential preemption/reschedule
point, they have the proper logic to recheck for atomicity violations.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>

...

This commit is contained in:

Gregory Haskins 2008-12-29 09:39:51 -05:00

parent 7e96fa5875

commit 8f45e2b516

1 changed files with 44 additions and 7 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

51

kernel/sched.c

View file