mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-13 14:04:05 +08:00
c725dafc95
PREEMPT_RT does not spin and wait until a running timer completes its callback but instead it blocks on a sleeping lock to prevent a livelock in the case that the task waiting for the callback completion preempted the callback. This cannot be done for timers flagged with TIMER_IRQSAFE. These timers can be canceled from an interrupt disabled context even on RT kernels. The expiry callback of such timers is invoked with interrupts disabled so there is no need to use the expiry lock mechanism because obviously the callback cannot be preempted even on RT kernels. Do not use the timer_base::expiry_lock mechanism when waiting for a running callback to complete if the timer is flagged with TIMER_IRQSAFE. Also add a lockdep assertion for RT kernels to validate that the expiry lock mechanism is always invoked in preemptible context. Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201103190937.hga67rqhvknki3tp@linutronix.de |
||
|---|---|---|
| .. | ||
| alarmtimer.c | ||
| clockevents.c | ||
| clocksource.c | ||
| hrtimer.c | ||
| itimer.c | ||
| jiffies.c | ||
| Kconfig | ||
| Makefile | ||
| namespace.c | ||
| ntp_internal.h | ||
| ntp.c | ||
| posix-clock.c | ||
| posix-cpu-timers.c | ||
| posix-stubs.c | ||
| posix-timers.c | ||
| posix-timers.h | ||
| sched_clock.c | ||
| test_udelay.c | ||
| tick-broadcast-hrtimer.c | ||
| tick-broadcast.c | ||
| tick-common.c | ||
| tick-internal.h | ||
| tick-oneshot.c | ||
| tick-sched.c | ||
| tick-sched.h | ||
| time.c | ||
| timeconst.bc | ||
| timeconv.c | ||
| timecounter.c | ||
| timekeeping_debug.c | ||
| timekeeping_internal.h | ||
| timekeeping.c | ||
| timekeeping.h | ||
| timer_list.c | ||
| timer.c | ||
| vsyscall.c | ||