From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org,
dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com,
fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com
Subject: Re: [PATCH RFC tip/core/rcu 1/9] rcu: Add call_rcu_tasks()
Date: Tue, 29 Jul 2014 09:50:55 +0200 [thread overview]
Message-ID: <20140729075055.GY19379@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1406588180-21933-1-git-send-email-paulmck@linux.vnet.ibm.com>
[-- Attachment #1: Type: text/plain, Size: 939 bytes --]
On Mon, Jul 28, 2014 at 03:56:12PM -0700, Paul E. McKenney wrote:
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index bc1638b33449..a0d2f3a03566 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -2762,6 +2762,7 @@ need_resched:
> } else {
> deactivate_task(rq, prev, DEQUEUE_SLEEP);
> prev->on_rq = 0;
> + rcu_note_voluntary_context_switch(prev);
>
> /*
> * If a worker went to sleep, notify and ask workqueue
> @@ -2828,6 +2829,7 @@ asmlinkage __visible void __sched schedule(void)
> struct task_struct *tsk = current;
>
> sched_submit_work(tsk);
> + rcu_note_voluntary_context_switch(tsk);
> __schedule();
> }
Yeah, not entirely happy with that, you add two calls into one of the
hotest paths of the kernel.
And I'm still not entirely sure why, your 0/x babbled something about
trampolines, but I'm not sure I understand how those lead to this.
[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]
next prev parent reply other threads:[~2014-07-29 7:51 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-28 22:55 [PATCH tip/core/rcu 0/9] RCU-tasks implementation Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 1/9] rcu: Add call_rcu_tasks() Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 2/9] rcu: Provide cond_resched_rcu_qs() to force quiescent states in long loops Paul E. McKenney
2014-07-29 7:55 ` Peter Zijlstra
2014-07-29 16:22 ` Paul E. McKenney
2014-07-29 17:25 ` Peter Zijlstra
2014-07-29 17:33 ` Paul E. McKenney
2014-07-29 17:36 ` Peter Zijlstra
2014-07-29 17:37 ` Peter Zijlstra
2014-07-29 17:55 ` Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 3/9] rcu: Add synchronous grace-period waiting for RCU-tasks Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 4/9] rcu: Export RCU-tasks APIs to GPL modules Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 5/9] rcutorture: Add torture tests for RCU-tasks Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 6/9] rcutorture: Add RCU-tasks test cases Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 7/9] rcu: Add stall-warning checks for RCU-tasks Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 8/9] rcu: Make RCU-tasks track exiting tasks Paul E. McKenney
2014-07-30 17:04 ` Oleg Nesterov
2014-07-30 18:24 ` Paul E. McKenney
2014-07-28 22:56 ` [PATCH RFC tip/core/rcu 9/9] rcu: Improve RCU-tasks energy efficiency Paul E. McKenney
2014-07-29 7:50 ` Peter Zijlstra [this message]
2014-07-29 15:57 ` [PATCH RFC tip/core/rcu 1/9] rcu: Add call_rcu_tasks() Paul E. McKenney
2014-07-29 16:07 ` Peter Zijlstra
2014-07-29 16:33 ` Paul E. McKenney
2014-07-29 17:31 ` Peter Zijlstra
2014-07-29 18:19 ` Paul E. McKenney
2014-07-29 19:25 ` Peter Zijlstra
2014-07-29 20:11 ` Paul E. McKenney
2014-07-29 8:12 ` Peter Zijlstra
2014-07-29 16:36 ` Paul E. McKenney
2014-07-29 8:12 ` Peter Zijlstra
2014-07-29 8:14 ` Peter Zijlstra
2014-07-29 17:23 ` Paul E. McKenney
2014-07-29 17:33 ` Peter Zijlstra
2014-07-29 18:06 ` Paul E. McKenney
2014-07-30 13:23 ` Mike Galbraith
2014-07-30 14:23 ` Paul E. McKenney
2014-07-31 7:37 ` Mike Galbraith
2014-07-31 16:38 ` Paul E. McKenney
2014-08-01 2:59 ` Mike Galbraith
2014-08-01 15:16 ` Paul E. McKenney
2014-07-30 6:52 ` Lai Jiangshan
2014-07-30 15:07 ` Paul E. McKenney
2014-07-30 13:41 ` Frederic Weisbecker
2014-07-30 16:10 ` Paul E. McKenney
2014-07-30 15:49 ` Oleg Nesterov
2014-07-30 16:08 ` Paul E. McKenney
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=20140729075055.GY19379@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=bobby.prani@gmail.com \
--cc=dhowells@redhat.com \
--cc=dipankar@in.ibm.com \
--cc=dvhart@linux.intel.com \
--cc=edumazet@google.com \
--cc=fweisbec@gmail.com \
--cc=josh@joshtriplett.org \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.desnoyers@efficios.com \
--cc=mingo@kernel.org \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/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
Powered by JetHome