From:   Thomas Gleixner <tglx@linutronix.de>
To:     "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Michael Nazzareno Trimarchi <michael@amarulasolutions.com>,
        John Stultz <jstultz@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Stephen Boyd <sboyd@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
        Michael <michael@mipisi.de>, kernel-team@android.com,
        Peter Zijlstra <peterz@infradead.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [RFC][PATCH 2/2] time: alarmtimer: Use TASK_FREEZABLE to
 cleanup freezer handling
In-Reply-To: <CAJZ5v0iWZqAcbqdTuKbo35Gk6vNS0h9De20GDNZeZvqfhQiSWA@mail.gmail.com>
References: <20230211064527.3481754-1-jstultz@google.com>
 <20230211064527.3481754-2-jstultz@google.com>
 <CAOf5uwnW1u=nfFnj3C8kCVmhgwRaVh6sHZR1RGnXdbrCNpkGVg@mail.gmail.com>
 <87o7porea9.ffs@tglx>
 <CAOf5uwmhtQ8GXhMiE-Y3-wgL5=xfjOv0Tpq1vqPB8p=LyZHBmw@mail.gmail.com>
 <CAOf5uwmpayJwpAFzUS6qsCgdpyek1f-2t2t9YNr76vnRjSC8=w@mail.gmail.com>
 <87a618qlcp.ffs@tglx>
 <CAOf5uw=a2RYYFj+4_WOX+KaF_FCXSsUgfM+T2m2XjVuqKMdooA@mail.gmail.com>
 <87sff0ox1a.ffs@tglx>
 <CAJZ5v0iWZqAcbqdTuKbo35Gk6vNS0h9De20GDNZeZvqfhQiSWA@mail.gmail.com>
Date:   Thu, 02 Mar 2023 23:21:43 +0100
Message-ID: <87zg8ukd54.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Thu, Mar 02 2023 at 15:32, Rafael J. Wysocki wrote:
> On Mon, Feb 20, 2023 at 10:19 PM Thomas Gleixner <tglx@linutronix.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.