Hi!
[ 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.
I just wanted to check... AFAICT RCU_NONIDLE puts some quite heavy instrumentation around each statement; does it makes sense to group the statements into one in cases like this?
Best regards, Pavel
@@ -194,9 +194,9 @@ static int omap_enter_idle_coupled(struct cpuidle_device *dev, mpuss_can_lose_context) gic_dist_disable();
clkdm_deny_idle(cpu_clkdm[1]);omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);clkdm_allow_idle(cpu_clkdm[1]);
RCU_NONIDLE(clkdm_deny_idle(cpu_clkdm[1]));RCU_NONIDLE(omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON));RCU_NONIDLE(clkdm_allow_idle(cpu_clkdm[1]));if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) && mpuss_can_lose_context) {