In preparation for freezer to also use saved_state, remove the
CONFIG_PREEMPT_RT compilation guard around saved_state.
On the arm64 platform I tested which did not have CONFIG_PREEMPT_RT,
there was no statistically significant deviation by applying this patch.
Test methodology:
perf bench sched message -g 40 -l 40
Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
include/linux/sched.h | 2 --
kernel/sched/core.c | 17 +++--------------
2 files changed, 3 insertions(+), 16 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 609bde814cb0..14194a62294f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -745,10 +745,8 @@ struct task_struct {
#endif
unsigned int __state;
-#ifdef CONFIG_PREEMPT_RT
/* saved state for "spinlock sleepers" */
unsigned int saved_state;
-#endif
/*
* This begins the randomizable portion of task_struct. Only
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c52c2eba7c73..58921ab7442b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2219,31 +2219,21 @@ int __task_state_match(struct task_struct *p, unsigned int state)
if (READ_ONCE(p->__state) & state)
return 1;
-#ifdef CONFIG_PREEMPT_RT
if (READ_ONCE(p->saved_state) & state)
return -1;
-#endif
+
return 0;
}
static __always_inline
int task_state_match(struct task_struct *p, unsigned int state)
{
-#ifdef CONFIG_PREEMPT_RT
- int match;
-
/*
* Serialize against current_save_and_set_rtlock_wait_state() and
* current_restore_rtlock_saved_state().
*/
- raw_spin_lock_irq(&p->pi_lock);
- match = __task_state_match(p, state);
- raw_spin_unlock_irq(&p->pi_lock);
-
- return match;
-#else
+ guard(raw_spinlock_irq)(&p->pi_lock);
return __task_state_match(p, state);
-#endif
}
/*
@@ -4053,7 +4043,6 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success)
*success = !!(match = __task_state_match(p, state));
-#ifdef CONFIG_PREEMPT_RT
/*
* Saved state preserves the task state across blocking on
* an RT lock. If the state matches, set p::saved_state to
@@ -4069,7 +4058,7 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success)
*/
if (match < 0)
p->saved_state = TASK_RUNNING;
-#endif
+
return match > 0;
}
--
2.41.0
