[RFC PATCH 0/2] Reintroduce NEXT_BUDDY for EEVDF v2

[Mel Gorman <mgorman@techsingularity.net>]

I've been chasing down a number of schedule issues recently like many
others and found they were broadly grouped as

1. Failure to boost CPU frequency with powersave/ondemand governors
2. Processors entering idle states that are too deep
3. Differences in wakeup latencies for wakeup-intensive workloads

Adding topology into account means that there is a lot of
machine-specific behaviour which may explain why some discussions
recently have reproduction problems. Nevertheless, the removal of
LAST_BUDDY and NEXT_BUDDY being disabled has an impact on wakeup
latencies.

This RFC is to determine if this is valid approach to prefer selecting
a wakee if it's eligible to run even though other unrelated tasks are
more eligible.

 kernel/sched/fair.c     | 131 ++++++++++++++++++++++++++++++++++------
 kernel/sched/features.h |   2 +-
 2 files changed, 112 insertions(+), 21 deletions(-)

-- 
2.51.0