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From: Chen Ridong <chenridong@huaweicloud.com>
To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	bristot@redhat.com, vschneid@redhat.com, rafael@kernel.org,
	pavel@ucw.cz
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	lujialin4@huawei.com, chenridong@huawei.com
Subject: [PATCH 6.6 1/5] sched/core: Remove ifdeffery for saved_state
Date: Mon, 28 Jul 2025 02:41:17 +0000	[thread overview]
Message-ID: <20250728024121.33864-2-chenridong@huaweicloud.com> (raw)
In-Reply-To: <20250728024121.33864-1-chenridong@huaweicloud.com>

From: Elliot Berman <quic_eberman@quicinc.com>

[ Upstream commit fbaa6a181a4b1886cbf4214abdf9a2df68471510 ]

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@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
 include/linux/sched.h |  2 --
 kernel/sched/core.c   | 10 ++--------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 393c300347de..cb38eee732fd 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -753,10 +753,8 @@ 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 760a6c3781cb..ab6550fadecd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2238,17 +2238,15 @@ 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;
 
 	/*
@@ -2260,9 +2258,6 @@ int task_state_match(struct task_struct *p, unsigned int state)
 	raw_spin_unlock_irq(&p->pi_lock);
 
 	return match;
-#else
-	return __task_state_match(p, state);
-#endif
 }
 
 /*
@@ -4059,7 +4054,6 @@ 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
@@ -4075,7 +4069,7 @@ 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;
 }
 
-- 
2.34.1


  reply	other threads:[~2025-07-28  2:55 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <2025072421-deviate-skintight-bbd5@gregkh>
2025-07-28  2:41 ` [PATCH 6.6 0/5] [Backport] sched,freezer: Remove unnecessary warning in __thaw_task Chen Ridong
2025-07-28  2:41   ` Chen Ridong [this message]
2025-07-28  2:41   ` [PATCH 6.6 2/5] freezer,sched: Use saved_state to reduce some spurious wakeups Chen Ridong
2025-07-28  2:41   ` [PATCH 6.6 3/5] freezer,sched: Do not restore saved_state of a thawed task Chen Ridong
2025-07-28  2:41   ` [PATCH 6.6 4/5] freezer,sched: Clean saved_state when restoring it during thaw Chen Ridong
2025-07-28  2:41   ` [PATCH 6.6 5/5] sched,freezer: Remove unnecessary warning in __thaw_task Chen Ridong
2025-07-28  3:11   ` [PATCH 6.6 0/5] [Backport] " Chen Ridong

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