On Tue, 04/11 11:28, Kevin Wolf wrote:
> Am 10.04.2017 um 17:05 hat Fam Zheng geschrieben:
> > They start the coroutine on the specified context.
> >
> > Signed-off-by: Fam Zheng <f...@redhat.com>
> > ---
> > include/block/aio.h | 18 ++++++++++++++++++
> > util/async.c | 14 +++++++++++++-
> > 2 files changed, 31 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/block/aio.h b/include/block/aio.h
> > index 677b6ff..b0a6bb3 100644
> > --- a/include/block/aio.h
> > +++ b/include/block/aio.h
> > @@ -511,6 +511,24 @@ void aio_co_schedule(AioContext *ctx, struct Coroutine
> > *co);
> > void aio_co_wake(struct Coroutine *co);
> >
> > /**
> > + * aio_co_enter:
> > + * @ctx: the context to run the coroutine
> > + * @co: the coroutine to run
> > + *
> > + * Enter a coroutine in the specified AioContext.
> > + */
> > +void aio_co_enter(AioContext *ctx, struct Coroutine *co);
> > +
> > +/**
> > + * aio_co_enter_if_inactive:
> > + * @ctx: the context to run the coroutine
> > + * @co: the coroutine to run
> > + *
> > + * Enter a coroutine in the specified AioContext, if it's not already
> > entered.
> > + */
> > +void aio_co_enter_if_inactive(AioContext *ctx, struct Coroutine *co);
> > +
> > +/**
> > * Return the AioContext whose event loop runs in the current thread.
> > *
> > * If called from an IOThread this will be the IOThread's AioContext. If
> > diff --git a/util/async.c b/util/async.c
> > index 663e297..507671a 100644
> > --- a/util/async.c
> > +++ b/util/async.c
> > @@ -453,6 +453,11 @@ void aio_co_wake(struct Coroutine *co)
> > smp_read_barrier_depends();
> > ctx = atomic_read(&co->ctx);
> >
> > + aio_co_enter(ctx, co);
> > +}
> > +
> > +void aio_co_enter(AioContext *ctx, struct Coroutine *co)
> > +{
> > if (ctx != qemu_get_current_aio_context()) {
> > aio_co_schedule(ctx, co);
> > return;
> > @@ -464,11 +469,18 @@ void aio_co_wake(struct Coroutine *co)
> > QSIMPLEQ_INSERT_TAIL(&self->co_queue_wakeup, co, co_queue_next);
> > } else {
> > aio_context_acquire(ctx);
> > - qemu_coroutine_enter(co);
> > + qemu_aio_coroutine_enter(ctx, co);
> > aio_context_release(ctx);
> > }
> > }
> >
> > +void aio_co_enter_if_inactive(AioContext *ctx, struct Coroutine *co)
> > +{
> > + if (!qemu_coroutine_entered(co)) {
> > + aio_co_enter(ctx, co);
> > + }
> > +}
>
> Is this a useful function, though?
>
> I think the only interesting case is the first qemu_coroutine_enter()
> after a coroutine is created, here we may want it to run in a different
> AioContext than the caller. However, once this has happened, it is
> already running in the right AioContext and we can use the normal
> functions without giving an explicit AioContext (except in cases where
> we wouldn't reenter from a callback of that AioContext, but do such
> cases even exist?)
>
> So I expect that some patches down the series, we get a patch that
> converts more than is actually necessary. Let's see.
>
> Kevin
You are right, actually this function is unused.
Fam
