From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>, RCU <rcu@vger.kernel.org>,
"Paul E . McKenney" <paulmck@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Michal Hocko <mhocko@suse.com>,
Thomas Gleixner <tglx@linutronix.de>,
"Theodore Y . Ts'o" <tytso@mit.edu>,
Joel Fernandes <joel@joelfernandes.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Uladzislau Rezki <urezki@gmail.com>,
Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>,
Ingo Molnar <mingo@kernel.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>
Subject: [PATCH 04/16] preempt: Cleanup PREEMPT_COUNT leftovers
Date: Thu, 29 Oct 2020 17:50:07 +0100 [thread overview]
Message-ID: <20201029165019.14218-4-urezki@gmail.com> (raw)
In-Reply-To: <20201029165019.14218-1-urezki@gmail.com>
From: Thomas Gleixner <tglx@linutronix.de>
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: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
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 7d9c1c0e149c..513769b1edf8 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.
--
2.20.1
next prev parent reply other threads:[~2020-10-29 16:51 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 16:50 [PATCH 01/16] rcu/tree: Add a work to allocate pages from regular context Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 02/16] lib/debug: Remove pointless ARCH_NO_PREEMPT dependencies Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 03/16] preempt: Make preempt count unconditional Uladzislau Rezki (Sony)
2020-10-29 16:50 ` Uladzislau Rezki (Sony) [this message]
2020-10-29 16:50 ` [PATCH 05/16] lockdep: Cleanup PREEMPT_COUNT leftovers Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 06/16] mm/pagemap: " Uladzislau Rezki (Sony)
2020-10-29 20:57 ` Uladzislau Rezki
2020-10-29 21:26 ` Paul E. McKenney
2020-10-29 16:50 ` [PATCH 07/16] locking/bitspinlock: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 08/16] uaccess: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 09/16] sched: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 10/16] ARM: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 11/16] xtensa: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 12/16] drm/i915: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 13/16] rcutorture: " Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 14/16] preempt: Remove PREEMPT_COUNT from Kconfig Uladzislau Rezki (Sony)
2020-10-29 16:50 ` [PATCH 15/16] rcu/tree: Allocate a page when caller is preemptible Uladzislau Rezki (Sony)
2020-11-03 18:03 ` Joel Fernandes
2020-11-04 11:39 ` Uladzislau Rezki
2020-11-04 14:36 ` Joel Fernandes
2020-10-29 16:50 ` [PATCH 16/16] rcu/tree: Use delayed work instead of hrtimer to refill the cache Uladzislau Rezki (Sony)
2020-10-29 19:47 ` Paul E. McKenney
2020-10-29 20:13 ` Uladzislau Rezki
2020-10-29 20:22 ` Uladzislau Rezki
2020-10-29 20:33 ` Paul E. McKenney
2020-10-29 21:00 ` Uladzislau Rezki
2020-11-03 15:47 ` [PATCH 01/16] rcu/tree: Add a work to allocate pages from regular context Joel Fernandes
2020-11-03 16:33 ` Uladzislau Rezki
2020-11-03 19:18 ` Paul E. McKenney
2020-11-04 12:35 ` Uladzislau Rezki
2020-11-04 14:12 ` Paul E. McKenney
2020-11-04 14:40 ` Uladzislau Rezki
2020-11-03 17:54 ` Joel Fernandes
2020-11-04 12:12 ` Uladzislau Rezki
2020-11-04 15:01 ` Joel Fernandes
2020-11-04 18:38 ` Uladzislau Rezki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201029165019.14218-4-urezki@gmail.com \
--to=urezki@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=bristot@redhat.com \
--cc=bsegall@google.com \
--cc=dietmar.eggemann@arm.com \
--cc=joel@joelfernandes.org \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.com \
--cc=mingo@kernel.org \
--cc=oleksiy.avramchenko@sonymobile.com \
--cc=paulmck@kernel.org \
--cc=peterz@infradead.org \
--cc=rcu@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=tytso@mit.edu \
--cc=vincent.guittot@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).