From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
fweisbec@gmail.com, oleg@redhat.com, umgwanakikbuti@gmail.com,
tglx@linutronix.de, rostedt@goodmis.org,
Peter Zijlstra <peterz@infradead.org>
Subject: [RFC][PATCH 01/11] sched: Simplify INIT_PREEMPT_COUNT
Date: Tue, 29 Sep 2015 11:28:26 +0200 [thread overview]
Message-ID: <20150929093519.706413197@infradead.org> (raw)
In-Reply-To: <20150929092825.540553633@infradead.org>
[-- Attachment #1: peterz-kill-preempt_active-1.patch --]
[-- Type: text/plain, Size: 1285 bytes --]
As per commit d86ee4809d03 ("sched: optimize cond_resched()") we need
PREEMPT_ACTIVE to avoid cond_resched() from working before the
scheduler is setup.
However, keeping preemption disabled should do the same thing already,
making the PREEMPT_ACTIVE part entirely redundant.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
include/linux/sched.h | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -608,17 +608,14 @@ struct task_cputime_atomic {
/*
* Disable preemption until the scheduler is running.
* Reset by start_kernel()->sched_init()->init_idle().
- *
- * We include PREEMPT_ACTIVE to avoid cond_resched() from working
- * before the scheduler is active -- see should_resched().
*/
-#define INIT_PREEMPT_COUNT (PREEMPT_DISABLED + PREEMPT_ACTIVE)
+#define INIT_PREEMPT_COUNT PREEMPT_DISABLED
/**
* struct thread_group_cputimer - thread group interval timer counts
* @cputime_atomic: atomic thread group interval timers.
* @running: non-zero when there are timers running and
- * @cputime receives updates.
+ * @cputime receives updates.
*
* This structure contains the version of task_cputime, above, that is
* used for thread group CPU timer calculations.
next prev parent reply other threads:[~2015-09-29 9:45 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-29 9:28 [RFC][PATCH 00/11] sched: Killing PREEMPT_ACTIVE Peter Zijlstra
2015-09-29 9:28 ` Peter Zijlstra [this message]
2015-09-29 10:30 ` [tip:sched/core] sched/core: Simplify INIT_PREEMPT_COUNT tip-bot for Peter Zijlstra
2015-09-29 13:19 ` [RFC][PATCH 01/11] sched: " Frederic Weisbecker
2015-09-29 14:43 ` Steven Rostedt
2015-09-29 14:47 ` Peter Zijlstra
[not found] ` <20150929103729.00899e69@gandalf.local.home>
[not found] ` <20150929143559.GL3816@twins.programming.kicks-ass.net>
2015-09-29 15:00 ` Steven Rostedt
2015-09-29 15:05 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 02/11] sched: Create preempt_count invariant Peter Zijlstra
2015-09-29 10:30 ` [tip:sched/core] sched/core: " tip-bot for Peter Zijlstra
2015-09-29 12:55 ` [RFC][PATCH 02/11] sched: " Frederic Weisbecker
2015-09-29 13:02 ` Peter Zijlstra
2015-09-29 14:40 ` Steven Rostedt
2015-09-29 13:11 ` Thomas Gleixner
2015-09-29 14:09 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 03/11] sched: Robustify preemption leak checks Peter Zijlstra
2015-09-29 10:31 ` [tip:sched/core] sched/core: " tip-bot for Peter Zijlstra
2015-09-29 13:13 ` [RFC][PATCH 03/11] sched: " Thomas Gleixner
2015-09-29 13:25 ` Frederic Weisbecker
2015-09-29 14:24 ` Peter Zijlstra
2015-09-29 14:32 ` Frederic Weisbecker
2015-09-29 15:07 ` Steven Rostedt
2015-09-29 15:17 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 04/11] sched: Rework TASK_DEAD preemption exception Peter Zijlstra
2015-09-29 13:13 ` Thomas Gleixner
2015-09-29 13:41 ` Frederic Weisbecker
2015-09-29 15:10 ` Steven Rostedt
2015-09-29 9:28 ` [RFC][PATCH 05/11] sched: Add preempt argument to __schedule() Peter Zijlstra
2015-09-29 13:14 ` Thomas Gleixner
2015-09-29 13:18 ` Frederic Weisbecker
2015-09-29 15:28 ` Steven Rostedt
2015-09-29 15:30 ` Steven Rostedt
2015-09-29 15:29 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 06/11] sched: Fix trace_sched_switch() Peter Zijlstra
2015-09-29 13:15 ` Thomas Gleixner
2015-09-29 15:38 ` Steven Rostedt
2015-09-29 15:48 ` Peter Zijlstra
2015-09-29 16:30 ` Steven Rostedt
2015-09-29 9:28 ` [RFC][PATCH 07/11] sched: Stop setting PREEMPT_ACTIVE Peter Zijlstra
2015-09-29 13:16 ` Thomas Gleixner
2015-09-29 15:41 ` Steven Rostedt
2015-09-29 16:25 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 08/11] sched: Simplify preempt_count tests Peter Zijlstra
2015-09-29 13:17 ` Thomas Gleixner
2015-09-29 15:42 ` Steven Rostedt
2015-09-29 9:28 ` [RFC][PATCH 09/11] sched, x86: Kill saved_preempt_count Peter Zijlstra
2015-09-29 13:18 ` Thomas Gleixner
2015-09-29 15:44 ` Steven Rostedt
2015-09-29 15:46 ` Peter Zijlstra
2015-09-29 9:28 ` [RFC][PATCH 10/11] sched: Kill PREEMPT_ACTIVE Peter Zijlstra
2015-09-29 13:18 ` Thomas Gleixner
2015-09-29 15:45 ` Steven Rostedt
2015-09-29 9:28 ` [RFC][PATCH 11/11] sched: More notrace Peter Zijlstra
2015-09-29 13:19 ` Thomas Gleixner
2015-09-29 15:58 ` Steven Rostedt
2015-09-29 10:27 ` [RFC][PATCH 12/11] sched: Add preempt_count invariant check Peter Zijlstra
2015-09-29 10:32 ` Peter Zijlstra
2015-09-29 10:56 ` [RFC][PATCH v2 " Peter Zijlstra
2015-09-29 11:55 ` Linus Torvalds
2015-09-29 11:55 ` Peter Zijlstra
2015-09-29 10:34 ` [RFC][PATCH 00/11] sched: Killing PREEMPT_ACTIVE Ingo Molnar
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