Messages in this thread | | | From | Oliver <> | Date | Tue, 11 Dec 2018 10:18:31 +1100 | Subject | Re: [PATCH] powerpc: eeh_event: convert semaphore to completion |
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On Tue, Dec 11, 2018 at 8:52 AM Arnd Bergmann <arnd@arndb.de> wrote: > > For this use case, completions and semaphores are equivalent, > but semaphores are an awkward interface that should generally > be avoided, so use the completion instead.
IIRC Sam has been reworking the locking used inside of EEH so this is probably going to clash with his changes. Converting to a completion is probably a good idea, but we might want to do it as a part of his series since it's going to collide with this anyway.
Sam, what do you think?
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/powerpc/kernel/eeh_event.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/arch/powerpc/kernel/eeh_event.c b/arch/powerpc/kernel/eeh_event.c > index 61c9356bf9c9..227e57f980df 100644 > --- a/arch/powerpc/kernel/eeh_event.c > +++ b/arch/powerpc/kernel/eeh_event.c > @@ -35,7 +35,7 @@ > */ > > static DEFINE_SPINLOCK(eeh_eventlist_lock); > -static struct semaphore eeh_eventlist_sem; > +static DECLARE_COMPLETION(eeh_eventlist_event); > static LIST_HEAD(eeh_eventlist); > > /** > @@ -55,7 +55,7 @@ static int eeh_event_handler(void * dummy) > struct eeh_pe *pe; > > while (!kthread_should_stop()) { > - if (down_interruptible(&eeh_eventlist_sem)) > + if (wait_for_completion_interruptible(&eeh_eventlist_event)) > break; > > /* Fetch EEH event from the queue */ > @@ -102,9 +102,6 @@ int eeh_event_init(void) > struct task_struct *t; > int ret = 0; > > - /* Initialize semaphore */ > - sema_init(&eeh_eventlist_sem, 0); > - > t = kthread_run(eeh_event_handler, NULL, "eehd"); > if (IS_ERR(t)) { > ret = PTR_ERR(t); > @@ -142,7 +139,7 @@ int eeh_send_failure_event(struct eeh_pe *pe) > spin_unlock_irqrestore(&eeh_eventlist_lock, flags); > > /* For EEH deamon to knick in */ > - up(&eeh_eventlist_sem); > + complete(&eeh_eventlist_event); > > return 0; > } > -- > 2.20.0 >
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