From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] tracing/irqtrace: only call trace_hardirqs_on/off when state changes
Date: Tue, 1 May 2018 16:00:59 -0400 [thread overview]
Message-ID: <20180501160059.6df6aae4@gandalf.local.home> (raw)
In-Reply-To: <20180501194838.GK12217@hirez.programming.kicks-ass.net>
On Tue, 1 May 2018 21:48:38 +0200
Peter Zijlstra <peterz@infradead.org> wrote:
> On Tue, May 01, 2018 at 03:38:40PM -0400, Steven Rostedt wrote:
> > On Tue, 1 May 2018 21:19:51 +0200
> > Peter Zijlstra <peterz@infradead.org> wrote:
>
> > > Now, lockdep only minimally tracks these otherwise redundant operations;
> > > see redundant_hardirqs_{on,off} counters, and loosing that doesn't seen
> > > like a big issue.
> > >
> > > But I'm confused how this helps track superfluous things, it looks like
> > > it explicitly tracks _less_ superfluous transitions.
> >
> > I think it is about triggering on OFF->OFF a warning, as that would
> > only happen if we have:
> >
> > local_irq_save(flags);
> > [..]
> > local_irq_disable();
> >
>
> Ahh, ok. Yes, that is easier to do with these changes. The alternative
> is to add more information to the tracehooks such that we can do the
> same internally, but whatever.
>
> Yeah, I'm fine with the proposed change, but maybe improve the Changelog
> a little for slow people like me :-)
Great!
Nicholas,
I know this is an old patch (from last November), but want to send it
again with a proper change log and signed off by?
-- Steve
next prev parent reply other threads:[~2018-05-01 20:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-16 16:15 [PATCH] tracing/irqtrace: only call trace_hardirqs_on/off when state changes Nicholas Piggin
2018-05-01 18:46 ` Steven Rostedt
2018-05-01 19:19 ` Peter Zijlstra
2018-05-01 19:38 ` Steven Rostedt
2018-05-01 19:48 ` Peter Zijlstra
2018-05-01 20:00 ` Steven Rostedt [this message]
2018-05-01 21:15 ` Joel Fernandes
2018-05-02 0:12 ` Nicholas Piggin
2018-07-11 1:44 ` Steven Rostedt
2018-07-11 5:58 ` Joel Fernandes
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