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
next prev parent 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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