Messages in this thread | | | Subject | Re: [PATCH] cpu/hotplug: Fix rollback during error-out in takedown_cpu() | From | Mukesh Ojha <> | Date | Tue, 4 Sep 2018 17:42:28 +0530 |
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On 9/4/2018 12:03 PM, Neeraj Upadhyay wrote: > If takedown_cpu() fails during _cpu_down(), st->state is reset, > by calling cpuhp_reset_state(). This results in an additional > increment of st->state, which results in CPUHP_AP_SMPBOOT_THREADS > state being skipped during rollback. Fix this by not calling > cpuhp_reset_state() and doing the state reset directly in > _cpu_down(). > > Fixes: 4dddfb5faa61 ("smp/hotplug: Rewrite AP state machine core") > Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> > --- > kernel/cpu.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/kernel/cpu.c b/kernel/cpu.c > index aa7fe85..9f49edb 100644 > --- a/kernel/cpu.c > +++ b/kernel/cpu.c > @@ -970,7 +970,14 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, > */ > ret = cpuhp_down_callbacks(cpu, st, target); > if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { > - cpuhp_reset_state(st, prev_state); > + /* > + * As st->last is not set, cpuhp_reset_state() increments > + * st->state, which results in CPUHP_AP_SMPBOOT_THREADS being > + * skipped during rollback. So, don't use it here. > + */ > + st->rollback = true; > + st->target = prev_state; > + st->bringup = !st->bringup;
Acked-by: Mukesh Ojha <mojha@codeaurora.org>
looks valid for this case.
> __cpuhp_kick_ap(st); > } >
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