kernel/stop_machine.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
rcu_momentary_dyntick_idle() is getting called from all the irq
disable path(also documented in rcu_momentary_dyntick_idle())
however, in multi_cpu_stop() it is not.
"
* Let the RCU core know that this CPU has gone through the scheduler,
* which is a quiescent state. This is called when the need for a
* quiescent state is urgent, so we burn an atomic operation and full
* memory barriers to let the RCU core know about it, regardless of what
* this CPU might (or might not) do in the near future.
*
* We inform the RCU core by emulating a zero-duration dyntick-idle period.
*
* The caller must have disabled interrupts and must not be idle.
"
Let's fix this as it is possible that during stop_machine() call for
a kprobe registration[1] can get stuck when one cpu(cpu4) calls
rcu_momentary_dyntick_idle() after acking MULTI_STOP_PREPARE state[2]
and other cpus have acked MULTI_STOP_DISABLE_IRQ and waiting for earlier
cpu to reach to next state [3].
[1]
[<ffffffdb78c75c54>] __switch_to+0x1e8
[<ffffffdb78c76520>] __schedule+0x6bc
[<ffffffdb78c76af0>] preempt_schedule_common+0xb4
[<ffffffdb78c75e60>] preempt_schedule[jt]+0x20
[<ffffffdb77dd7bd0>] queue_stop_cpus_work[jt]+0xdc
[<ffffffdb77dd781c>] stop_machine_cpuslocked+0xdc
[<ffffffdb78c816f8>] aarch64_insn_patch_text[jt]+0x4c
[<ffffffdb78c81938>] arch_arm_kprobe+0x40
[<ffffffdb77de88c0>] arm_kprobe+0x3c
[<ffffffdb77de84f4>] register_kprobe+0x3fc
[2]
000|check_preemption_disabled(what1 = 0xFFFFFFDB79153D0B, what2 = 0xFFFFFFDB7912A911)
| what1 = 0xFFFFFFDB79153D0B
| what2 = 0xFFFFFFDB7912A911
-001|__this_cpu_preempt_check(op = ?)
-002|rcu_preempt_need_deferred_qs(inline)
| t = 0xFFFFFF8806879F80
| pscr_ret__ = 0
-002|rcu_preempt_deferred_qs(inline)
| t = 0xFFFFFF8806879F80
| flags = 0
-002|rcu_momentary_dyntick_idle()
-003|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_PREPARE ==> This seems to have acked MULTI_STOP_PREPARE
state and calls rcu_momentary_dyntick_idle()
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-004|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6D812F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-005|smpboot_thread_fn(:data = 0xFFFFFF8805C063C0)
| data = 0xFFFFFF8805C063C0
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-006|kthread(_create = 0xFFFFFF8806B7EC00)
| _create = 0xFFFFFF8806B7EC00
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C063C0
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806402F00
| done = 0xFFFFFFC08005BA98
-007|ret_from_fork(asm)
[3]
000|touch_softlockup_watchdog()
-001|touch_nmi_watchdog(inline)
-001|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| newstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-002|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6D04EF28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-003|smpboot_thread_fn(:data = 0xFFFFFF8805C06230)
| data = 0xFFFFFF8805C06230
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-004|kthread(_create = 0xFFFFFF8806469D80)
| _create = 0xFFFFFF8806469D80
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C06230
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806401500
| done = 0xFFFFFFC08005B888
-005|ret_from_fork(asm)
---|end of frame
cpu1:
-000|touch_softlockup_watchdog()
-001|touch_nmi_watchdog(inline)
-001|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| newstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-002|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6D23FF28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-003|smpboot_thread_fn(:data = 0xFFFFFF8805C06270)
| data = 0xFFFFFF8805C06270
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-004|kthread(_create = 0xFFFFFF88066119C0)
| _create = 0xFFFFFF88066119C0
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C06270
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806401000
| done = 0xFFFFFFC08005BA98
-005|ret_from_fork(asm)
---|end of frame
cpu2:
-000|touch_softlockup_watchdog()
-001|touch_nmi_watchdog(inline)
-001|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| newstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-002|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6D430F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-003|smpboot_thread_fn(:data = 0xFFFFFF8805C062E0)
| data = 0xFFFFFF8805C062E0
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-004|kthread(_create = 0xFFFFFF88067D5B80)
| _create = 0xFFFFFF88067D5B80
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C062E0
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806403F00
| done = 0xFFFFFFC08005BA98
-005|ret_from_fork(asm)
---|end of frame
cpu3:
-000|touch_softlockup_watchdog_sched(inline)
| __ptr = 18446743916840366040
-000|touch_softlockup_watchdog()
-001|touch_nmi_watchdog(inline)
-001|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| newstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-002|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6D621F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-003|smpboot_thread_fn(:data = 0xFFFFFF8805C06350)
| data = 0xFFFFFF8805C06350
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-004|kthread(_create = 0xFFFFFF88069E7300)
| _create = 0xFFFFFF88069E7300
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C06350
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806403300
| done = 0xFFFFFFC08005BA98
-005|ret_from_fork(asm)
---|end of frame
Cpu5:
-000|check_preemption_disabled(what1 = ?, what2 = ?)
| what1 = ?
| what2 = ?
-001|debug_smp_processor_id()
-002|ct_state_inc(inline)
| incby = 8
| __ptr = 0
-002|rcu_momentary_dyntick_idle()
| seq = 0
-003|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-004|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6DA03F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-005|smpboot_thread_fn(:data = 0xFFFFFF8805C06430)
| data = 0xFFFFFF8805C06430
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-006|kthread(_create = 0xFFFFFF8806D58180)
| _create = 0xFFFFFF8806D58180
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C06430
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806402400
| done = 0xFFFFFFC08005BA98
-007|ret_from_fork(asm)
---|end of frame
Cpu6:
-000|check_preemption_disabled(what1 = ?, what2 = ?)
| what1 = ?
| what2 = ?
-001|__this_cpu_preempt_check(op = ?)
-002|rcu_preempt_need_deferred_qs(inline)
| t = 0xFFFFFF8806E03F00
| pscr_ret__ = 0
-002|rcu_preempt_deferred_qs(inline)
| t = 0xFFFFFF8806E03F00
| flags = 0
-002|rcu_momentary_dyntick_idle()
-003|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-004|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6DBF4F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-005|smpboot_thread_fn(:data = 0xFFFFFF8805C064A0)
| data = 0xFFFFFF8805C064A0
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-006|kthread(_create = 0xFFFFFF8806F67D00)
| _create = 0xFFFFFF8806F67D00
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C064A0
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806402600
| done = 0xFFFFFFC08005BA98
-007|ret_from_fork(asm)
---|end of frame
Cpu7:
-000|check_preemption_disabled(what1 = ?, what2 = ?)
| what1 = ?
| what2 = ?
-001|__this_cpu_preempt_check(op = ?)
-002|rcu_preempt_need_deferred_qs(inline)
| t = 0xFFFFFF8806E1DE80
| pscr_ret__ = 0
-002|rcu_preempt_deferred_qs(inline)
| t = 0xFFFFFF8806E1DE80
| flags = 0
-002|rcu_momentary_dyntick_idle()
-003|multi_cpu_stop(:data = 0xFFFFFFC084343478)
| data = 0xFFFFFFC084343478
| msdata = 0x0
| curstate = MULTI_STOP_DISABLE_IRQ
| flags = 0
| is_active = TRUE
| cpumask = 0xFFFFFFDB79E37718
| err = 0
-004|cpu_stopper_thread(cpu = ?)
| cpu = ?
| __already_done = FALSE
| stopper = 0xFFFFFF8B6DDE5F28
| fn = 0xFFFFFFDB77DD74C4
| arg = 0xFFFFFFC084343478
| done = 0xFFFFFFC0843434A0
| ret = ???
-005|smpboot_thread_fn(:data = 0xFFFFFF8805C06510)
| data = 0xFFFFFF8805C06510
| td = 0x0
| ht = 0xFFFFFFDB79EE8B40
-006|kthread(_create = 0xFFFFFF88070FF300)
| _create = 0xFFFFFF88070FF300
| param = (sched_priority = 0)
| create = 0x0
| data = 0xFFFFFF8805C06510
| threadfn = 0x0
| ret = ???
| self = 0xFFFFFF8806407D00
| done = 0xFFFFFFC08005BA98
-007|ret_from_fork(asm)
---|end of frame
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
---
kernel/stop_machine.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index cedb17ba158a..f93e6deb8150 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -250,8 +250,8 @@ static int multi_cpu_stop(void *data)
* be detected and reported on their side.
*/
touch_nmi_watchdog();
+ rcu_momentary_dyntick_idle();
}
- rcu_momentary_dyntick_idle();
} while (curstate != MULTI_STOP_EXIT);
local_irq_restore(flags);
--
2.7.4On Tue, Apr 09, 2024 at 01:32:16PM +0530, Mukesh Ojha wrote: > rcu_momentary_dyntick_idle() is getting called from all the irq > disable path(also documented in rcu_momentary_dyntick_idle()) > however, in multi_cpu_stop() it is not. > > " > > * Let the RCU core know that this CPU has gone through the scheduler, > * which is a quiescent state. This is called when the need for a > * quiescent state is urgent, so we burn an atomic operation and full > * memory barriers to let the RCU core know about it, regardless of what > * this CPU might (or might not) do in the near future. > * > * We inform the RCU core by emulating a zero-duration dyntick-idle period. > * > * The caller must have disabled interrupts and must not be idle. > > " > > > Let's fix this as it is possible that during stop_machine() call for > a kprobe registration[1] can get stuck when one cpu(cpu4) calls > rcu_momentary_dyntick_idle() after acking MULTI_STOP_PREPARE state[2] > and other cpus have acked MULTI_STOP_DISABLE_IRQ and waiting for earlier > cpu to reach to next state [3]. Good eyes! Acked-by: Paul E. McKenney <paulmck@kernel.org> > [1] > > [<ffffffdb78c75c54>] __switch_to+0x1e8 > [<ffffffdb78c76520>] __schedule+0x6bc > [<ffffffdb78c76af0>] preempt_schedule_common+0xb4 > [<ffffffdb78c75e60>] preempt_schedule[jt]+0x20 > [<ffffffdb77dd7bd0>] queue_stop_cpus_work[jt]+0xdc > [<ffffffdb77dd781c>] stop_machine_cpuslocked+0xdc > [<ffffffdb78c816f8>] aarch64_insn_patch_text[jt]+0x4c > [<ffffffdb78c81938>] arch_arm_kprobe+0x40 > [<ffffffdb77de88c0>] arm_kprobe+0x3c > [<ffffffdb77de84f4>] register_kprobe+0x3fc > > > [2] > 000|check_preemption_disabled(what1 = 0xFFFFFFDB79153D0B, what2 = 0xFFFFFFDB7912A911) > | what1 = 0xFFFFFFDB79153D0B > | what2 = 0xFFFFFFDB7912A911 > -001|__this_cpu_preempt_check(op = ?) > -002|rcu_preempt_need_deferred_qs(inline) > | t = 0xFFFFFF8806879F80 > | pscr_ret__ = 0 > -002|rcu_preempt_deferred_qs(inline) > | t = 0xFFFFFF8806879F80 > | flags = 0 > -002|rcu_momentary_dyntick_idle() > -003|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_PREPARE ==> This seems to have acked MULTI_STOP_PREPARE > state and calls rcu_momentary_dyntick_idle() > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -004|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6D812F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -005|smpboot_thread_fn(:data = 0xFFFFFF8805C063C0) > | data = 0xFFFFFF8805C063C0 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -006|kthread(_create = 0xFFFFFF8806B7EC00) > | _create = 0xFFFFFF8806B7EC00 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C063C0 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806402F00 > | done = 0xFFFFFFC08005BA98 > -007|ret_from_fork(asm) > > [3] > 000|touch_softlockup_watchdog() > -001|touch_nmi_watchdog(inline) > -001|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | newstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -002|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6D04EF28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -003|smpboot_thread_fn(:data = 0xFFFFFF8805C06230) > | data = 0xFFFFFF8805C06230 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -004|kthread(_create = 0xFFFFFF8806469D80) > | _create = 0xFFFFFF8806469D80 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C06230 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806401500 > | done = 0xFFFFFFC08005B888 > -005|ret_from_fork(asm) > ---|end of frame > > cpu1: > > -000|touch_softlockup_watchdog() > -001|touch_nmi_watchdog(inline) > -001|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | newstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -002|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6D23FF28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -003|smpboot_thread_fn(:data = 0xFFFFFF8805C06270) > | data = 0xFFFFFF8805C06270 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -004|kthread(_create = 0xFFFFFF88066119C0) > | _create = 0xFFFFFF88066119C0 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C06270 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806401000 > | done = 0xFFFFFFC08005BA98 > -005|ret_from_fork(asm) > ---|end of frame > > cpu2: > > -000|touch_softlockup_watchdog() > -001|touch_nmi_watchdog(inline) > -001|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | newstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -002|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6D430F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -003|smpboot_thread_fn(:data = 0xFFFFFF8805C062E0) > | data = 0xFFFFFF8805C062E0 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -004|kthread(_create = 0xFFFFFF88067D5B80) > | _create = 0xFFFFFF88067D5B80 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C062E0 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806403F00 > | done = 0xFFFFFFC08005BA98 > -005|ret_from_fork(asm) > ---|end of frame > > cpu3: > > -000|touch_softlockup_watchdog_sched(inline) > | __ptr = 18446743916840366040 > -000|touch_softlockup_watchdog() > -001|touch_nmi_watchdog(inline) > -001|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | newstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -002|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6D621F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -003|smpboot_thread_fn(:data = 0xFFFFFF8805C06350) > | data = 0xFFFFFF8805C06350 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -004|kthread(_create = 0xFFFFFF88069E7300) > | _create = 0xFFFFFF88069E7300 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C06350 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806403300 > | done = 0xFFFFFFC08005BA98 > -005|ret_from_fork(asm) > ---|end of frame > > > Cpu5: > > -000|check_preemption_disabled(what1 = ?, what2 = ?) > | what1 = ? > | what2 = ? > -001|debug_smp_processor_id() > -002|ct_state_inc(inline) > | incby = 8 > | __ptr = 0 > -002|rcu_momentary_dyntick_idle() > | seq = 0 > -003|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -004|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6DA03F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -005|smpboot_thread_fn(:data = 0xFFFFFF8805C06430) > | data = 0xFFFFFF8805C06430 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -006|kthread(_create = 0xFFFFFF8806D58180) > | _create = 0xFFFFFF8806D58180 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C06430 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806402400 > | done = 0xFFFFFFC08005BA98 > -007|ret_from_fork(asm) > ---|end of frame > > Cpu6: > > -000|check_preemption_disabled(what1 = ?, what2 = ?) > | what1 = ? > | what2 = ? > -001|__this_cpu_preempt_check(op = ?) > -002|rcu_preempt_need_deferred_qs(inline) > | t = 0xFFFFFF8806E03F00 > | pscr_ret__ = 0 > -002|rcu_preempt_deferred_qs(inline) > | t = 0xFFFFFF8806E03F00 > | flags = 0 > -002|rcu_momentary_dyntick_idle() > -003|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -004|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6DBF4F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -005|smpboot_thread_fn(:data = 0xFFFFFF8805C064A0) > | data = 0xFFFFFF8805C064A0 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -006|kthread(_create = 0xFFFFFF8806F67D00) > | _create = 0xFFFFFF8806F67D00 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C064A0 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806402600 > | done = 0xFFFFFFC08005BA98 > -007|ret_from_fork(asm) > ---|end of frame > > Cpu7: > > -000|check_preemption_disabled(what1 = ?, what2 = ?) > | what1 = ? > | what2 = ? > -001|__this_cpu_preempt_check(op = ?) > -002|rcu_preempt_need_deferred_qs(inline) > | t = 0xFFFFFF8806E1DE80 > | pscr_ret__ = 0 > -002|rcu_preempt_deferred_qs(inline) > | t = 0xFFFFFF8806E1DE80 > | flags = 0 > -002|rcu_momentary_dyntick_idle() > -003|multi_cpu_stop(:data = 0xFFFFFFC084343478) > | data = 0xFFFFFFC084343478 > | msdata = 0x0 > | curstate = MULTI_STOP_DISABLE_IRQ > | flags = 0 > | is_active = TRUE > | cpumask = 0xFFFFFFDB79E37718 > | err = 0 > -004|cpu_stopper_thread(cpu = ?) > | cpu = ? > | __already_done = FALSE > | stopper = 0xFFFFFF8B6DDE5F28 > | fn = 0xFFFFFFDB77DD74C4 > | arg = 0xFFFFFFC084343478 > | done = 0xFFFFFFC0843434A0 > | ret = ??? > -005|smpboot_thread_fn(:data = 0xFFFFFF8805C06510) > | data = 0xFFFFFF8805C06510 > | td = 0x0 > | ht = 0xFFFFFFDB79EE8B40 > -006|kthread(_create = 0xFFFFFF88070FF300) > | _create = 0xFFFFFF88070FF300 > | param = (sched_priority = 0) > | create = 0x0 > | data = 0xFFFFFF8805C06510 > | threadfn = 0x0 > | ret = ??? > | self = 0xFFFFFF8806407D00 > | done = 0xFFFFFFC08005BA98 > -007|ret_from_fork(asm) > ---|end of frame > > > Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> > --- > kernel/stop_machine.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c > index cedb17ba158a..f93e6deb8150 100644 > --- a/kernel/stop_machine.c > +++ b/kernel/stop_machine.c > @@ -250,8 +250,8 @@ static int multi_cpu_stop(void *data) > * be detected and reported on their side. > */ > touch_nmi_watchdog(); > + rcu_momentary_dyntick_idle(); > } > - rcu_momentary_dyntick_idle(); > } while (curstate != MULTI_STOP_EXIT); > > local_irq_restore(flags); > -- > 2.7.4 >
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