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authorJuri Lelli <juri.lelli@redhat.com>2021-02-08 08:35:54 +0100
committerIngo Molnar <mingo@kernel.org>2021-02-17 14:12:42 +0100
commite0ee463c93c43b1657ad69cf2678ff5bf1b754fe (patch)
treed2adb4faf2fd97e0df50a6ad64f6ab625343f13a /kernel/sched/features.h
parentsched/features: Fix hrtick reprogramming (diff)
downloadlinux-dev-e0ee463c93c43b1657ad69cf2678ff5bf1b754fe.tar.xz
linux-dev-e0ee463c93c43b1657ad69cf2678ff5bf1b754fe.zip
sched/features: Distinguish between NORMAL and DEADLINE hrtick
The HRTICK feature has traditionally been servicing configurations that need precise preemptions point for NORMAL tasks. More recently, the feature has been extended to also service DEADLINE tasks with stringent runtime enforcement needs (e.g., runtime < 1ms with HZ=1000). Enabling HRTICK sched feature currently enables the additional timer and task tick for both classes, which might introduced undesired overhead for no additional benefit if one needed it only for one of the cases. Separate HRTICK sched feature in two (and leave the traditional case name unmodified) so that it can be selectively enabled when needed. With: $ echo HRTICK > /sys/kernel/debug/sched_features the NORMAL/fair hrtick gets enabled. With: $ echo HRTICK_DL > /sys/kernel/debug/sched_features the DEADLINE hrtick gets enabled. Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210208073554.14629-3-juri.lelli@redhat.com
Diffstat (limited to 'kernel/sched/features.h')
-rw-r--r--kernel/sched/features.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index e875eabb6600..1bc2b158fc51 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -38,6 +38,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
SCHED_FEAT(WAKEUP_PREEMPTION, true)
SCHED_FEAT(HRTICK, false)
+SCHED_FEAT(HRTICK_DL, false)
SCHED_FEAT(DOUBLE_TICK, false)
/*