Hi. I only just started looking at sched_ext a couple of days ago so
feel free to correct me if sched_ext patches have different rules,
different cc's and different mailing lists than normal LKML.
This mini series delegates uclamp operations to each sched_class. The
problem with the current handling of uclamp is that it seems to be a
global thing but it conditions on sched_class->uclamp_enabled anyway, so
it is in fact already kind of sched_class-specific. So, remove
sched_class->uclamp_enabled and just let each class decide what to do.
More importantly, sched_ext no longer unconditionally follows the
existing uclamp implementation, but instead each custom scheduler
decides itself what to do. It can re-use the existing uclamp, ignore
uclamp completely, or have its own uclamp implementation.
Some simple testing with trace_printk() shows uclamp_rq_{inc,dec}() are
called successfully from a sched_ext scheduler:
[002] d..21 1016.017441: uclamp_rq_dec: sched_ext uclamp dec
[002] dN.21 1016.017456: uclamp_rq_inc: sched_ext uclamp inc
Hongyan Xia (2):
sched/uclamp: Delegate uclamp to each sched_class
sched/ext: Add BPF functions for uclamp inc and dec
kernel/sched/core.c | 14 ++------------
kernel/sched/ext.c | 16 ++++++++++++----
kernel/sched/fair.c | 6 ++----
kernel/sched/rt.c | 7 +++----
kernel/sched/sched.h | 15 +++++++++++----
tools/sched_ext/include/scx/common.bpf.h | 2 ++
6 files changed, 32 insertions(+), 28 deletions(-)
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2.34.1