linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [WARNING] kernel/rcu/tree.c:1058 rcu_irq_enter+0x15/0x20
Date: Fri, 2 Oct 2020 20:13:13 +0200	[thread overview]
Message-ID: <20201002181313.GM29142@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20201002135644.7903d0e5@gandalf.local.home>

On Fri, Oct 02, 2020 at 01:56:44PM -0400, Steven Rostedt wrote:
> On Wed, 30 Sep 2020 20:13:23 +0200
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > Blergh, IIRC there's header hell that way. The sane fix is killing off
> > that trace_*_rcuidle() disease.
> > 
> > But I think this will also cure it.
> 
> I guess you still don't build modules ;-). I had to add a
> EXPORT_SYMBOL(lockdep_recursion) to get it to build, and then move the

Correct, my regular configs are all without modules.

> checks within the irq disabling to get rid of the using cpu pointers within
> preemptable code warnings

Ah, I think I lost a s/__this_cpu_read/raw_cpu_read/ somewhere. The
thing is, if we're preemptible/migratable it will be 0 on both CPUs and
it doesn't matter which 0 we read. If it is !0, IRQs will be disabled
and we can't get migrated.

Anyway, let me go write a Changelog to go with it.

  reply	other threads:[~2020-10-02 18:13 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-17 17:16 [WARNING] kernel/rcu/tree.c:1058 rcu_irq_enter+0x15/0x20 Steven Rostedt
2020-09-17 17:18 ` Steven Rostedt
2020-09-25 20:07 ` Steven Rostedt
2020-09-30 18:13 ` Peter Zijlstra
2020-09-30 19:10   ` Steven Rostedt
2020-09-30 19:22     ` Peter Zijlstra
2020-09-30 19:52       ` Steven Rostedt
2020-10-02  9:04         ` Peter Zijlstra
2020-10-02 17:56   ` Steven Rostedt
2020-10-02 18:13     ` Peter Zijlstra [this message]
2020-10-05  7:52       ` Peter Zijlstra
2020-10-05  9:59         ` [PATCH] lockdep: Revert "lockdep: Use raw_cpu_*() for per-cpu variables" Peter Zijlstra
2020-10-07 16:20           ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2020-10-09  7:58           ` tip-bot2 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=20201002181313.GM29142@worktop.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --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;
as well as URLs for NNTP newsgroup(s).