LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Matt Fleming <matt@codeblueprint.co.uk>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>
Cc: Byungchul Park <byungchul.park@lge.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Luca Abeni <luca.abeni@unitn.it>, Rik van Riel <riel@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Wanpeng Li <wanpeng.li@hotmail.com>,
	Yuyang Du <yuyang.du@intel.com>, Petr Mladek <pmladek@suse.com>,
	Jan Kara <jack@suse.cz>,
	Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	linux-kernel@vger.kernel.org,
	Mel Gorman <mgorman@techsingularity.net>,
	Mike Galbraith <umgwanakikbuti@gmail.com>,
	Matt Fleming <matt@codeblueprint.co.uk>
Subject: [PATCH v2 5/7] sched/core: Reset RQCF_ACT_SKIP before unpinning rq->lock
Date: Wed, 21 Sep 2016 14:38:11 +0100
Message-ID: <20160921133813.31976-6-matt@codeblueprint.co.uk> (raw)
In-Reply-To: <20160921133813.31976-1-matt@codeblueprint.co.uk>

rq_clock() is called from sched_info_{depart,arrive}() after resetting
RQCF_ACT_SKIP but prior to a call to update_rq_clock().

In preparation for pending patches that check whether the rq clock has
been updated inside of a pin context before rq_clock() is called, move
the reset of rq->clock_skip_update immediately before unpinning the rq
lock.

This will avoid the new warnings which check if update_rq_clock() is
being actively skipped.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 kernel/sched/core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7950c372fca0..1254629c9f2f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2871,6 +2871,9 @@ context_switch(struct rq *rq, struct task_struct *prev,
 		prev->active_mm = NULL;
 		rq->prev_mm = oldmm;
 	}
+
+	rq->clock_skip_update = 0;
+
 	/*
 	 * Since the runqueue lock will be released by the next
 	 * task (which is an invalid locking op but in the case
@@ -3387,7 +3390,6 @@ static void __sched notrace __schedule(bool preempt)
 	next = pick_next_task(rq, prev, &rf);
 	clear_tsk_need_resched(prev);
 	clear_preempt_need_resched();
-	rq->clock_skip_update = 0;
 
 	if (likely(prev != next)) {
 		rq->nr_switches++;
@@ -3397,6 +3399,7 @@ static void __sched notrace __schedule(bool preempt)
 		trace_sched_switch(preempt, prev, next);
 		rq = context_switch(rq, prev, next, &rf); /* unlocks the rq */
 	} else {
+		rq->clock_skip_update = 0;
 		rq_unpin_lock(rq, &rf);
 		raw_spin_unlock_irq(&rq->lock);
 	}
-- 
2.9.3

  parent reply index

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-21 13:38 [PATCH v2 0/7] sched: Diagnostic checks for missing rq clock updates Matt Fleming
2016-09-21 13:38 ` [PATCH v2 1/7] sched/fair: Update the rq clock before detaching tasks Matt Fleming
2016-10-03 12:49   ` Peter Zijlstra
2016-10-03 14:37     ` Matt Fleming
2016-10-03 14:42       ` Peter Zijlstra
2016-09-21 13:38 ` [PATCH v2 2/7] sched/fair: Update rq clock before waking up new task Matt Fleming
2016-09-21 13:38 ` [PATCH v2 3/7] sched/fair: Update rq clock in task_hot() Matt Fleming
2016-09-21 13:38 ` [PATCH v2 4/7] sched: Add wrappers for lockdep_(un)pin_lock() Matt Fleming
2017-01-14 12:40   ` [tip:sched/core] sched/core: " tip-bot for Matt Fleming
2016-09-21 13:38 ` Matt Fleming [this message]
2017-01-14 12:41   ` [tip:sched/core] sched/core: Reset RQCF_ACT_SKIP before unpinning rq->lock tip-bot for Matt Fleming
2016-09-21 13:38 ` [PATCH v2 6/7] sched/fair: Push rq lock pin/unpin into idle_balance() Matt Fleming
2017-01-14 12:41   ` [tip:sched/core] " tip-bot for Matt Fleming
2016-09-21 13:38 ` [PATCH v2 7/7] sched/core: Add debug code to catch missing update_rq_clock() Matt Fleming
2016-09-21 15:58   ` Petr Mladek
2016-09-21 19:08     ` Matt Fleming
2016-09-21 19:46       ` Thomas Gleixner
2016-09-22  0:44       ` Sergey Senozhatsky
2016-09-22  8:04     ` Peter Zijlstra
2016-09-22  8:36       ` Jan Kara
2016-09-22  9:39         ` Peter Zijlstra
2016-09-22 10:17           ` Peter Zijlstra
2017-01-14 12:44   ` [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls tip-bot for Matt Fleming
     [not found]     ` <87tw8gutp6.fsf@concordia.ellerman.id.au>
2017-01-30 21:34       ` Matt Fleming
2017-01-31  8:35         ` Michael Ellerman
2017-01-31 11:00         ` Sachin Sant
2017-01-31 11:48           ` Mike Galbraith
2017-01-31 17:22             ` Ross Zwisler
2017-02-02 15:55               ` Peter Zijlstra
2017-02-02 22:01                 ` Matt Fleming
2017-02-03  3:05                 ` Mike Galbraith
2017-02-03  4:33                 ` Sachin Sant
2017-02-03  8:53                   ` Peter Zijlstra
2017-02-03 12:59                     ` Mike Galbraith
2017-02-03 13:37                       ` Peter Zijlstra
2017-02-03 13:52                         ` Mike Galbraith
2017-02-03 15:44                         ` Paul E. McKenney
2017-02-03 15:54                           ` Paul E. McKenney
2017-02-06  6:23                             ` Sachin Sant
2017-02-06 15:10                               ` Paul E. McKenney
2017-02-06 15:14                                 ` Paul E. McKenney
2017-02-03 13:04                 ` Borislav Petkov
2017-02-22  9:03                 ` Wanpeng Li
2017-02-24  9:16                 ` [tip:sched/urgent] sched/core: Fix update_rq_clock() splat on hotplug (and suspend/resume) tip-bot for Peter Zijlstra

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=20160921133813.31976-6-matt@codeblueprint.co.uk \
    --to=matt@codeblueprint.co.uk \
    --cc=byungchul.park@lge.com \
    --cc=fweisbec@gmail.com \
    --cc=jack@suse.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luca.abeni@unitn.it \
    --cc=mgorman@techsingularity.net \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=pmladek@suse.com \
    --cc=riel@redhat.com \
    --cc=sergey.senozhatsky.work@gmail.com \
    --cc=tglx@linutronix.de \
    --cc=umgwanakikbuti@gmail.com \
    --cc=wanpeng.li@hotmail.com \
    --cc=yuyang.du@intel.com \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git