sched: remove HZ_BW feature hedge

As a hedge against unexpected user issues commit 88c56cfeaec4
("sched/fair: Block nohz tick_stop when cfs bandwidth in use")
included a scheduler feature to disable the new functionality.
It's been a few releases (v6.6) and no screams, so remove it.

Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20240515133705.3632915-1-pauld@redhat.com

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index db5823fcc31c6dac0fa4a154aa1a8022a94ce1e4..0a71050f5f0dd279979cbabe39e94ab3707c88df 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1269,7 +1269,7 @@ bool sched_can_stop_tick(struct rq *rq)
         * dequeued by migrating while the constrained task continues to run.
         * E.g. going from 2->1 without going through pick_next_task().
         */
-       if (sched_feat(HZ_BW) && __need_bw_check(rq, rq->curr)) {
+       if (__need_bw_check(rq, rq->curr)) {
                if (cfs_task_bw_constrained(rq->curr))
                        return false;
        }

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e8cdfeb898e2767966f85a0e13a59ee6ec626b78..02694fc5fce9ca3ff5baa9f2177a9ce4cbdf8c13 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6555,7 +6555,7 @@ static void sched_fair_update_stop_tick(struct rq *rq, struct task_struct *p)
 {
        int cpu = cpu_of(rq);
 
-       if (!sched_feat(HZ_BW) || !cfs_bandwidth_used())
+       if (!cfs_bandwidth_used())
                return;
 
        if (!tick_nohz_full_cpu(cpu))

diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 143f55df890b1ec2ca8fbfdc3aa658982cfbcc80..929021fd6bc43a9cf7007dd8e69a666ddfcc643c 100644 (file)
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -85,5 +85,3 @@ SCHED_FEAT(WA_BIAS, true)
 SCHED_FEAT(UTIL_EST, true)
 
 SCHED_FEAT(LATENCY_WARN, false)
-
-SCHED_FEAT(HZ_BW, true)