| Message ID | 20200909151149.490589-12-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | monitor: Optionally run handlers in coroutines | expand |
On Wed, Sep 09, 2020 at 05:11:47PM +0200, Kevin Wolf wrote: > Add a function that can be used to move the currently running coroutine > to a different AioContext (and therefore potentially a different > thread). > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > include/block/aio.h | 10 ++++++++++ > util/async.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 40 insertions(+) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Additional nitpick detail on Kevin's request. Kevin Wolf <kwolf@redhat.com> writes: > Add a function that can be used to move the currently running coroutine > to a different AioContext (and therefore potentially a different > thread). > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > --- > include/block/aio.h | 10 ++++++++++ > util/async.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 40 insertions(+) > > diff --git a/include/block/aio.h b/include/block/aio.h > index b2f703fa3f..c37617b404 100644 > --- a/include/block/aio.h > +++ b/include/block/aio.h > @@ -17,6 +17,7 @@ > #ifdef CONFIG_LINUX_IO_URING > #include <liburing.h> > #endif > +#include "qemu/coroutine.h" > #include "qemu/queue.h" > #include "qemu/event_notifier.h" > #include "qemu/thread.h" > @@ -654,6 +655,15 @@ static inline bool aio_node_check(AioContext *ctx, bool is_external) > */ > void aio_co_schedule(AioContext *ctx, struct Coroutine *co); > > +/** > + * aio_co_reschedule_self: > + * @new_ctx: the new context > + * > + * Move the currently running coroutine to new_ctx. If the coroutine is already > + * running in new_ctx, do nothing. Wrapping the comment around column 70 or so would make it easier to read. Up to you. > + */ > +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx); > + > /** > * aio_co_wake: > * @co: the coroutine > diff --git a/util/async.c b/util/async.c > index 4266745dee..a609e18693 100644 > --- a/util/async.c > +++ b/util/async.c > @@ -569,6 +569,36 @@ void aio_co_schedule(AioContext *ctx, Coroutine *co) > aio_context_unref(ctx); > } > > +typedef struct AioCoRescheduleSelf { > + Coroutine *co; > + AioContext *new_ctx; > +} AioCoRescheduleSelf; > + > +static void aio_co_reschedule_self_bh(void *opaque) > +{ > + AioCoRescheduleSelf *data = opaque; > + aio_co_schedule(data->new_ctx, data->co); > +} > + > +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx) > +{ > + AioContext *old_ctx = qemu_get_current_aio_context(); > + > + if (old_ctx != new_ctx) { > + AioCoRescheduleSelf data = { > + .co = qemu_coroutine_self(), > + .new_ctx = new_ctx, > + }; > + /* > + * We can't directly schedule the coroutine in the target context > + * because this would be racy: The other thread could try to enter the > + * coroutine before it has yielded in this one. > + */ Likewise. > + aio_bh_schedule_oneshot(old_ctx, aio_co_reschedule_self_bh, &data); > + qemu_coroutine_yield(); > + } > +} > + > void aio_co_wake(struct Coroutine *co) > { > AioContext *ctx;
diff --git a/include/block/aio.h b/include/block/aio.h index b2f703fa3f..c37617b404 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -17,6 +17,7 @@ #ifdef CONFIG_LINUX_IO_URING #include <liburing.h> #endif +#include "qemu/coroutine.h" #include "qemu/queue.h" #include "qemu/event_notifier.h" #include "qemu/thread.h" @@ -654,6 +655,15 @@ static inline bool aio_node_check(AioContext *ctx, bool is_external) */ void aio_co_schedule(AioContext *ctx, struct Coroutine *co); +/** + * aio_co_reschedule_self: + * @new_ctx: the new context + * + * Move the currently running coroutine to new_ctx. If the coroutine is already + * running in new_ctx, do nothing. + */ +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx); + /** * aio_co_wake: * @co: the coroutine diff --git a/util/async.c b/util/async.c index 4266745dee..a609e18693 100644 --- a/util/async.c +++ b/util/async.c @@ -569,6 +569,36 @@ void aio_co_schedule(AioContext *ctx, Coroutine *co) aio_context_unref(ctx); } +typedef struct AioCoRescheduleSelf { + Coroutine *co; + AioContext *new_ctx; +} AioCoRescheduleSelf; + +static void aio_co_reschedule_self_bh(void *opaque) +{ + AioCoRescheduleSelf *data = opaque; + aio_co_schedule(data->new_ctx, data->co); +} + +void coroutine_fn aio_co_reschedule_self(AioContext *new_ctx) +{ + AioContext *old_ctx = qemu_get_current_aio_context(); + + if (old_ctx != new_ctx) { + AioCoRescheduleSelf data = { + .co = qemu_coroutine_self(), + .new_ctx = new_ctx, + }; + /* + * We can't directly schedule the coroutine in the target context + * because this would be racy: The other thread could try to enter the + * coroutine before it has yielded in this one. + */ + aio_bh_schedule_oneshot(old_ctx, aio_co_reschedule_self_bh, &data); + qemu_coroutine_yield(); + } +} + void aio_co_wake(struct Coroutine *co) { AioContext *ctx;
Add a function that can be used to move the currently running coroutine to a different AioContext (and therefore potentially a different thread). Signed-off-by: Kevin Wolf <kwolf@redhat.com> --- include/block/aio.h | 10 ++++++++++ util/async.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+)