From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: core/rcu] preempt: Cleanup PREEMPT_COUNT leftovers
Date: Fri, 09 Oct 2020 17:01:28 -0000 [thread overview]
Message-ID: <160226288816.7002.14635860661393046833.tip-bot2@tip-bot2> (raw)
The following commit has been merged into the core/rcu branch of tip:
Commit-ID: a19bfa918cdfbb43157bb2ab5c8df364b241b77b
Gitweb: https://git.kernel.org/tip/a19bfa918cdfbb43157bb2ab5c8df364b241b77b
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 14 Sep 2020 19:21:01 +02:00
Committer: Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 28 Sep 2020 16:03:18 -07:00
preempt: Cleanup PREEMPT_COUNT leftovers
CONFIG_PREEMPT_COUNT is now unconditionally enabled and will be
removed. Cleanup the leftovers before doing so.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
include/linux/preempt.h | 37 ++++---------------------------------
1 file changed, 4 insertions(+), 33 deletions(-)
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index 7d9c1c0..513769b 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -56,8 +56,7 @@
#define PREEMPT_DISABLED (PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
/*
- * Disable preemption until the scheduler is running -- use an unconditional
- * value so that it also works on !PREEMPT_COUNT kernels.
+ * Disable preemption until the scheduler is running.
*
* Reset by start_kernel()->sched_init()->init_idle()->init_idle_preempt_count().
*/
@@ -69,7 +68,6 @@
*
* preempt_count() == 2*PREEMPT_DISABLE_OFFSET
*
- * Note: PREEMPT_DISABLE_OFFSET is 0 for !PREEMPT_COUNT kernels.
* Note: See finish_task_switch().
*/
#define FORK_PREEMPT_COUNT (2*PREEMPT_DISABLE_OFFSET + PREEMPT_ENABLED)
@@ -106,11 +104,7 @@
/*
* The preempt_count offset after preempt_disable();
*/
-#if defined(CONFIG_PREEMPT_COUNT)
-# define PREEMPT_DISABLE_OFFSET PREEMPT_OFFSET
-#else
-# define PREEMPT_DISABLE_OFFSET 0
-#endif
+#define PREEMPT_DISABLE_OFFSET PREEMPT_OFFSET
/*
* The preempt_count offset after spin_lock()
@@ -122,8 +116,8 @@
*
* spin_lock_bh()
*
- * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and
- * softirqs, such that unlock sequences of:
+ * Which need to disable both preemption and softirqs, such that unlock
+ * sequences of:
*
* spin_unlock();
* local_bh_enable();
@@ -164,8 +158,6 @@ extern void preempt_count_sub(int val);
#define preempt_count_inc() preempt_count_add(1)
#define preempt_count_dec() preempt_count_sub(1)
-#ifdef CONFIG_PREEMPT_COUNT
-
#define preempt_disable() \
do { \
preempt_count_inc(); \
@@ -231,27 +223,6 @@ do { \
__preempt_count_dec(); \
} while (0)
-#else /* !CONFIG_PREEMPT_COUNT */
-
-/*
- * Even if we don't have any preemption, we need preempt disable/enable
- * to be barriers, so that we don't have things like get_user/put_user
- * that can cause faults and scheduling migrate into our preempt-protected
- * region.
- */
-#define preempt_disable() barrier()
-#define sched_preempt_enable_no_resched() barrier()
-#define preempt_enable_no_resched() barrier()
-#define preempt_enable() barrier()
-#define preempt_check_resched() do { } while (0)
-
-#define preempt_disable_notrace() barrier()
-#define preempt_enable_no_resched_notrace() barrier()
-#define preempt_enable_notrace() barrier()
-#define preemptible() 0
-
-#endif /* CONFIG_PREEMPT_COUNT */
-
#ifdef MODULE
/*
* Modules have no business playing preemption tricks.
reply other threads:[~2020-10-09 17:01 UTC|newest]
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