From: Tony Lindgren <tony@atomide.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Barry Song" <baohua@kernel.org>,
linux-samsung-soc@vger.kernel.org,
"Maxime Ripard" <maxime.ripard@bootlin.com>,
"Frank Rowand" <frank.rowand@am.sony.com>,
linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org,
"Russell King" <linux@armlinux.org.uk>,
"Krzysztof Kozlowski" <krzk@kernel.org>,
"Patrice Chotard" <patrice.chotard@st.com>,
"David Brown" <david.brown@linaro.org>,
"Chen-Yu Tsai" <wens@csie.org>, "Kukjin Kim" <kgene@kernel.org>,
"Wei Xu" <xuwei5@hisilicon.com>,
"Viresh Kumar" <vireshk@kernel.org>,
"Andy Gross" <andy.gross@linaro.org>,
tglx@linutronix.de, linux-omap@vger.kernel.org,
"Shiraz Hashim" <shiraz.linux.kernel@gmail.com>,
"Andreas Färber" <afaerber@suse.de>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm: Convert arm boot_lock to raw
Date: Fri, 4 May 2018 08:21:37 -0700 [thread overview]
Message-ID: <20180504152137.GC98604@atomide.com> (raw)
In-Reply-To: <20180504105600.20613-1-bigeasy@linutronix.de>
* Sebastian Andrzej Siewior <bigeasy@linutronix.de> [180504 10:58]:
> From: Frank Rowand <frank.rowand@am.sony.com>
>
> The arm boot_lock is used by the secondary processor startup code. The locking
> task is the idle thread, which has idle->sched_class == &idle_sched_class.
> idle_sched_class->enqueue_task == NULL, so if the idle task blocks on the
> lock, the attempt to wake it when the lock becomes available will fail:
>
> try_to_wake_up()
> ...
> activate_task()
> enqueue_task()
> p->sched_class->enqueue_task(rq, p, flags)
>
> Fix by converting boot_lock to a raw spin lock.
Still works for me:
Tested-by: Tony Lindgren <tony@atomide.com>
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm: Convert arm boot_lock to raw
Date: Fri, 4 May 2018 08:21:37 -0700 [thread overview]
Message-ID: <20180504152137.GC98604@atomide.com> (raw)
In-Reply-To: <20180504105600.20613-1-bigeasy@linutronix.de>
* Sebastian Andrzej Siewior <bigeasy@linutronix.de> [180504 10:58]:
> From: Frank Rowand <frank.rowand@am.sony.com>
>
> The arm boot_lock is used by the secondary processor startup code. The locking
> task is the idle thread, which has idle->sched_class == &idle_sched_class.
> idle_sched_class->enqueue_task == NULL, so if the idle task blocks on the
> lock, the attempt to wake it when the lock becomes available will fail:
>
> try_to_wake_up()
> ...
> activate_task()
> enqueue_task()
> p->sched_class->enqueue_task(rq, p, flags)
>
> Fix by converting boot_lock to a raw spin lock.
Still works for me:
Tested-by: Tony Lindgren <tony@atomide.com>
next prev parent reply other threads:[~2018-05-04 15:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-04 10:55 [PATCH] arm: Convert arm boot_lock to raw Sebastian Andrzej Siewior
2018-05-04 10:55 ` Sebastian Andrzej Siewior
2018-05-04 10:55 ` [PATCH] arm: kprobe: replace patch_lock to raw lock Sebastian Andrzej Siewior
2018-05-04 10:56 ` [PATCH] arm/unwind: use a raw_spin_lock Sebastian Andrzej Siewior
2018-05-04 15:21 ` Tony Lindgren [this message]
2018-05-04 15:21 ` [PATCH] arm: Convert arm boot_lock to raw Tony Lindgren
2018-05-06 18:23 ` Krzysztof Kozlowski
2018-05-06 18:23 ` Krzysztof Kozlowski
2018-05-07 7:33 ` Sebastian Andrzej Siewior
2018-05-07 7:33 ` Sebastian Andrzej Siewior
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