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From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
	linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Carsten Emde <C.Emde@osadl.org>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	John Kacur <jkacur@redhat.com>, Daniel Wagner <wagi@monom.org>,
	Tom Zanussi <zanussi@kernel.org>,
	"Srivatsa S. Bhat" <srivatsa@csail.mit.edu>
Subject: [PATCH RT 08/10] locking: Drop might_resched() from might_sleep_no_state_check()
Date: Mon, 22 Nov 2021 15:38:55 -0500	[thread overview]
Message-ID: <20211122203904.807323639@goodmis.org> (raw)
In-Reply-To: <20211122203847.390551309@goodmis.org>

5.10.78-rt56-rc2 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

might_sleep_no_state_check() serves the same purpose as might_sleep()
except it is used before sleeping locks are acquired and therefore does
not check task_struct::state because the state is preserved.

That state is preserved in the locking slow path so we must not schedule
at the begin of the locking function because the state will be lost and
not preserved at that time.

Remove might_resched() from might_sleep_no_state_check() to avoid losing the
state before it is preserved.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 include/linux/kernel.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 2cff7554395d..6eb0ab994f4c 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -222,7 +222,7 @@ extern void __cant_migrate(const char *file, int line);
 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 
 # define might_sleep_no_state_check() \
-	do { ___might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
+	do { ___might_sleep(__FILE__, __LINE__, 0); } while (0)
 
 /**
  * cant_sleep - annotation for functions that cannot sleep
-- 
2.33.0

  parent reply	other threads:[~2021-11-22 20:39 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-22 20:38 [PATCH RT 00/10] Linux 5.10.78-rt56-rc2 Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 01/10] mm, zsmalloc: Convert zsmalloc_handle.lock to spinlock_t Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 02/10] sched: Fix get_push_task() vs migrate_disable() Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 03/10] sched: Switch wait_task_inactive to HRTIMER_MODE_REL_HARD Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 04/10] preempt: Move preempt_enable_no_resched() to the RT block Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 05/10] mm: Disable NUMA_BALANCING_DEFAULT_ENABLED and TRANSPARENT_HUGEPAGE on PREEMPT_RT Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 06/10] fscache: Use only one fscache_object_cong_wait Steven Rostedt
2021-11-22 20:38 ` [PATCH RT 07/10] fscache: Use only one fscache_object_cong_wait (2) Steven Rostedt
2021-11-22 20:38 ` Steven Rostedt [this message]
2021-11-22 20:38 ` [PATCH RT 09/10] drm/i915/gt: Queue and wait for the irq_work item Steven Rostedt
2021-11-23  8:25   ` Sebastian Andrzej Siewior
2021-11-23 15:37     ` Steven Rostedt
2021-11-24 16:12       ` Sebastian Andrzej Siewior
2021-11-24 16:12         ` [PATCH RT 1/3] irq_work: Allow irq_work_sync() to sleep if irq_work() no IRQ support Sebastian Andrzej Siewior
2021-11-24 16:12         ` [PATCH RT 2/3] irq_work: Handle some irq_work in a per-CPU thread on PREEMPT_RT Sebastian Andrzej Siewior
2021-11-24 16:12         ` [PATCH RT 3/3] irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ " Sebastian Andrzej Siewior
2021-11-22 20:38 ` [PATCH RT 10/10] Linux 5.10.78-rt56-rc2 Steven Rostedt

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