From: Juri Lelli juri.lelli@redhat.com
[ Upstream commit a73f863af4ce9730795eab7097fb2102e6854365 ]
Commit:
765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds")
made sched features static for !CONFIG_SCHED_DEBUG configurations, but overlooked the CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL cases.
For the latter echoing changes to /sys/kernel/debug/sched_features has the nasty effect of effectively changing what sched_features reports, but without actually changing the scheduler behaviour (since different translation units get different sysctl_sched_features).
Fix CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL configurations by properly restructuring ifdefs.
Fixes: 765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds") Co-developed-by: Daniel Bristot de Oliveira bristot@redhat.com Signed-off-by: Daniel Bristot de Oliveira bristot@redhat.com Signed-off-by: Juri Lelli juri.lelli@redhat.com Signed-off-by: Ingo Molnar mingo@kernel.org Acked-by: Patrick Bellasi patrick.bellasi@matbug.net Reviewed-by: Valentin Schneider valentin.schneider@arm.com Link: https://lore.kernel.org/r/20201013053114.160628-1-juri.lelli@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/core.c | 2 +- kernel/sched/sched.h | 13 ++++++++++--- 2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2d95dc3f46444..b1e0da56abcac 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -43,7 +43,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(sched_update_nr_running_tp);
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) +#ifdef CONFIG_SCHED_DEBUG /* * Debugging: various feature bits * diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 28709f6b0975c..8d1ca65db3b0d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1629,7 +1629,7 @@ enum {
#undef SCHED_FEAT
-#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) +#ifdef CONFIG_SCHED_DEBUG
/* * To support run-time toggling of sched features, all the translation units @@ -1637,6 +1637,7 @@ enum { */ extern const_debug unsigned int sysctl_sched_features;
+#ifdef CONFIG_JUMP_LABEL #define SCHED_FEAT(name, enabled) \ static __always_inline bool static_branch_##name(struct static_key *key) \ { \ @@ -1649,7 +1650,13 @@ static __always_inline bool static_branch_##name(struct static_key *key) \ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
-#else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */ +#else /* !CONFIG_JUMP_LABEL */ + +#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) + +#endif /* CONFIG_JUMP_LABEL */ + +#else /* !SCHED_DEBUG */
/* * Each translation unit has its own copy of sysctl_sched_features to allow @@ -1665,7 +1672,7 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features =
#define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
-#endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */ +#endif /* SCHED_DEBUG */
extern struct static_key_false sched_numa_balancing; extern struct static_key_false sched_schedstats;