[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAOf5uwkR2TpXN=+D2Gz1M8MDfZn51g1Dqv6eFxSfciBSVA-f=A@mail.gmail.com>
Date: Thu, 27 Jun 2024 09:46:24 +0200
From: Michael Nazzareno Trimarchi <michael@...rulasolutions.com>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>, John Stultz <jstultz@...gle.com>,
LKML <linux-kernel@...r.kernel.org>, Stephen Boyd <sboyd@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Michael <michael@...isi.de>, kernel-team@...roid.com,
Peter Zijlstra <peterz@...radead.org>
Subject: Re: [RFC][PATCH 2/2] time: alarmtimer: Use TASK_FREEZABLE to cleanup
freezer handling
Hi Thomas
On Thu, Mar 2, 2023 at 11:58 PM Thomas Gleixner <tglx@...utronix.de> wrote:
>
> On Thu, Mar 02 2023 at 23:21, Thomas Gleixner wrote:
> > On Thu, Mar 02 2023 at 15:32, Rafael J. Wysocki wrote:
> >> On Mon, Feb 20, 2023 at 10:19 PM Thomas Gleixner <tglx@...utronix.de> wrote:
> >>> +static atomic_t alarmtimer_wakeup;
> >>>
> >>> /**
> >>> * alarmtimer_fired - Handles alarm hrtimer being fired.
> >>> @@ -194,6 +196,8 @@ static enum hrtimer_restart alarmtimer_f
> >>> int ret = HRTIMER_NORESTART;
> >>> int restart = ALARMTIMER_NORESTART;
> >>>
> >>> + atomic_inc(&alarmtimer_wakeup);
> >>> +
> >>
> >> This appears to be still somewhat racy, because the notifier can run
> >> at this point AFAICS.
> >
> > Indeed it is. Let me think more about this.
>
> All of this is inherently racy as there is zero feedback whether the
> event has been consumed or not. Making this feedback based is not
> necessarily trivial, but let me stare into that.
>
Sorry to come back on this topic but I would like to know, if we can
find a way to be sure
to not lost wakeup or if you have already addressed in some series
Michael
> Thanks,
>
> tglx
>
--
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael@...rulasolutions.com
__________________________________
Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info@...rulasolutions.com
www.amarulasolutions.com
Powered by blists - more mailing lists