697091f927
[ Upstream commit 06862d789ddde8a99c1e579e934ca17c15a84755 ]
We get suspcious RCU usage splats with cpuidle in several places in
omap_enter_idle_coupled() with the kernel debug options enabled:
RCU used illegally from extended quiescent state!
...
(_raw_spin_lock_irqsave)
(omap_enter_idle_coupled+0x17c/0x2d8)
(omap_enter_idle_coupled)
(cpuidle_enter_state)
(cpuidle_enter_state_coupled)
(cpuidle_enter)
Let's use RCU_NONIDLE to suppress these splats. Things got changed around
with commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the
idle path") that started triggering these warnings.
For the tick_broadcast related calls, ideally we'd just switch over to
using CPUIDLE_FLAG_TIMER_STOP for omap_enter_idle_coupled() to have the
generic cpuidle code handle the tick_broadcast related calls for us and
then just drop the tick_broadcast calls here.
But we're currently missing the call in the common cpuidle code for
tick_broadcast_enable() that CPU1 hotplug needs as described in earlier
commit 50d6b3cf9403 ("ARM: OMAP2+: fix lack of timer interrupts on CPU1
after hotplug").
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.