bf29cb238d
CONFIG_NO_HZ_FULL doesn't make sense without CONFIG_CPU_ISOLATION. In
fact enabling the first without the second is a regression as nohz_full=
boot parameter gets silently ignored.
Besides this unnatural combination hangs RCU gp kthread when running
rcutorture for reasons that are not yet fully understood:
rcu_preempt kthread starved for 9974 jiffies! g4294967208
+c4294967207 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0
rcu_preempt I 7464 8 2 0x80000000
Call Trace:
__schedule+0x493/0x620
schedule+0x24/0x40
schedule_timeout+0x330/0x3b0
? preempt_count_sub+0xea/0x140
? collect_expired_timers+0xb0/0xb0
rcu_gp_kthread+0x6bf/0xef0
This commit therefore makes NO_HZ_FULL select CPU_ISOLATION, which
prevents all these bad behaviours.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <kernellwp@gmail.com>
Fixes:
|
||
---|---|---|
.. | ||
alarmtimer.c | ||
clockevents.c | ||
clocksource.c | ||
hrtimer.c | ||
itimer.c | ||
jiffies.c | ||
Kconfig | ||
Makefile | ||
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 |