From: "Paul E. McKenney" <paulmck@kernel.org>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Linux Next Mailing List <linux-next@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>
Subject: Re: linux-next: manual merge of the rcu tree with the tip tree
Date: Fri, 29 May 2020 07:15:01 -0700 [thread overview]
Message-ID: <20200529141501.GC2869@paulmck-ThinkPad-P72> (raw)
In-Reply-To: <20200529164132.6fb46471@canb.auug.org.au>
On Fri, May 29, 2020 at 04:41:32PM +1000, Stephen Rothwell wrote:
> Hi all,
>
> On Fri, 29 May 2020 16:22:34 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > Hi all,
> >
> > Today's linux-next merge of the rcu tree got a conflict in:
> >
> > kernel/rcu/tree.c
> >
> > between commits:
> >
> > 806f04e9fd2c ("rcu: Allow for smp_call_function() running callbacks from idle")
> > aaf2bc50df1f ("rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()")
> >
> > from the tip tree and commit:
> >
> > c0601bb42994 ("rcu/tree: Clean up dynticks counter usage")
> > 3f3baaf3ac07 ("rcu/tree: Remove dynticks_nmi_nesting counter")
> >
> > from the rcu tree.
> >
> > I fixed it up (I punted and took some from the former and some from the
> > latter) and can carry the fix as necessary. This is now fixed as far as
> > linux-next is concerned, but any non trivial conflicts should be mentioned
> > to your upstream maintainer when your tree is submitted for merging.
> > You may also want to consider cooperating with the maintainer of the
> > conflicting tree to minimise any particularly complex conflicts.
>
> I redid this and the resolution is below, but you should look at the
> final file when I do the release.
Given that the merge window might be opening in a couple days, my thought
is to defer these -rcu commits to my v5.9 pile, and then I resolve this
conflict in the -rcu tree when v5.8-rc1 comes out. I just now adjusted
the -rcu tree's rcu/next branch accordingly.
Seem reasonable?
Thanx, Paul
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc kernel/rcu/tree.c
> index c716eadc7617,78125749638f..1426b968eec1
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@@ -427,14 -385,8 +386,12 @@@ EXPORT_SYMBOL_GPL(rcu_momentary_dyntick
> */
> static int rcu_is_cpu_rrupt_from_idle(void)
> {
> - long nesting;
> -
> - /* Called only from within the scheduling-clock interrupt */
> - lockdep_assert_in_irq();
> + /*
> + * Usually called from the tick; but also used from smp_function_call()
> + * for expedited grace periods. This latter can result in running from
> + * the idle task, instead of an actual IPI.
> + */
> + lockdep_assert_irqs_disabled();
>
> /* Check for counter underflows */
> RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) < 0,
> @@@ -778,24 -718,6 +723,21 @@@ void rcu_irq_exit_preempt(void
> "RCU in extended quiescent state!");
> }
>
> +#ifdef CONFIG_PROVE_RCU
> +/**
> + * rcu_irq_exit_check_preempt - Validate that scheduling is possible
> + */
> +void rcu_irq_exit_check_preempt(void)
> +{
> + lockdep_assert_irqs_disabled();
> +
> + RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) <= 0,
> + "RCU dynticks_nesting counter underflow/zero!");
> - RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nmi_nesting) !=
> - DYNTICK_IRQ_NONIDLE,
> - "Bad RCU dynticks_nmi_nesting counter\n");
> + RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(),
> + "RCU in extended quiescent state!");
> +}
> +#endif /* #ifdef CONFIG_PROVE_RCU */
> +
> /*
> * Wrapper for rcu_irq_exit() where interrupts are enabled.
> *
next prev parent reply other threads:[~2020-05-29 14:15 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-29 6:22 linux-next: manual merge of the rcu tree with the tip tree Stephen Rothwell
2020-05-29 6:41 ` Stephen Rothwell
2020-05-29 14:15 ` Paul E. McKenney [this message]
2020-05-29 23:38 ` Stephen Rothwell
-- strict thread matches above, loose matches on Subject: below --
2024-02-27 1:55 Stephen Rothwell
2022-04-06 2:45 Stephen Rothwell
2022-04-06 16:28 ` Paul E. McKenney
2022-02-21 18:17 broonie
2021-10-12 4:48 Stephen Rothwell
2021-10-13 16:31 ` Paul E. McKenney
2021-08-17 7:09 Stephen Rothwell
2021-06-23 5:33 Stephen Rothwell
2021-06-22 4:51 Stephen Rothwell
2021-06-22 4:47 Stephen Rothwell
2021-06-22 5:04 ` Stephen Rothwell
2021-06-22 17:10 ` Paul E. McKenney
2020-10-09 4:59 Stephen Rothwell
2020-07-29 6:23 Stephen Rothwell
2020-06-26 3:14 Stephen Rothwell
2020-06-25 2:44 Stephen Rothwell
2020-06-25 3:44 ` Paul E. McKenney
2020-06-24 3:04 Stephen Rothwell
2020-06-24 4:06 ` Paul E. McKenney
2020-03-25 3:08 Stephen Rothwell
2020-03-25 3:18 ` Paul E. McKenney
2020-03-25 21:31 ` Paul E. McKenney
2019-12-19 0:50 Stephen Rothwell
2019-12-19 1:27 ` Paul E. McKenney
2019-12-19 1:31 ` Paul E. McKenney
2019-12-19 8:41 ` Peter Zijlstra
2019-12-19 13:38 ` Paul E. McKenney
2019-12-16 23:37 Stephen Rothwell
2018-06-22 2:27 Stephen Rothwell
2018-06-26 19:33 ` Paul E. McKenney
2017-11-10 2:14 Stephen Rothwell
2017-08-22 4:13 Stephen Rothwell
2017-07-31 3:50 Stephen Rothwell
2017-07-31 16:13 ` Paul E. McKenney
2017-08-01 0:04 ` Mathieu Desnoyers
2017-08-01 4:03 ` Paul E. McKenney
2017-08-01 4:25 ` Mathieu Desnoyers
2017-08-01 16:31 ` Paul E. McKenney
2017-08-01 13:43 ` Andy Lutomirski
2017-08-01 13:58 ` Peter Zijlstra
2017-08-01 14:15 ` Peter Zijlstra
2017-08-01 14:17 ` Andy Lutomirski
2017-08-01 14:02 ` Mathieu Desnoyers
2017-08-01 14:15 ` Andy Lutomirski
2017-08-01 15:40 ` Mathieu Desnoyers
2017-08-01 21:36 ` Paul E. McKenney
2016-07-18 5:26 Stephen Rothwell
2016-07-19 3:00 ` Paul E. McKenney
2016-06-09 5:14 Stephen Rothwell
2016-06-09 15:59 ` Paul E. McKenney
2016-03-04 4:13 Stephen Rothwell
2016-03-04 15:04 ` Paul E. McKenney
2015-07-16 2:57 Stephen Rothwell
2015-05-07 3:56 Stephen Rothwell
2014-02-24 4:18 Stephen Rothwell
2014-02-24 4:42 ` Paul E. McKenney
2012-09-05 3:59 Stephen Rothwell
2012-09-05 16:39 ` Paul E. McKenney
2012-09-05 17:11 ` Peter Zijlstra
2012-08-23 3:01 Stephen Rothwell
2012-08-23 3:22 ` Paul E. McKenney
2012-08-22 4:27 Stephen Rothwell
2012-08-22 5:05 ` Paul E. McKenney
2012-08-22 4:27 Stephen Rothwell
2012-08-22 5:03 ` Paul E. McKenney
2011-06-20 4:47 Stephen Rothwell
2011-06-20 15:17 ` 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=20200529141501.GC2869@paulmck-ThinkPad-P72 \
--to=paulmck@kernel.org \
--cc=hpa@zytor.com \
--cc=joel@joelfernandes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=sfr@canb.auug.org.au \
--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;
as well as URLs for NNTP newsgroup(s).