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authorStefan Hajnoczi <stefanha@redhat.com>2016-12-01 19:26:44 +0000
committerStefan Hajnoczi <stefanha@redhat.com>2017-01-03 16:38:48 +0000
commitee68697551cd81186c5b12eba10c158350cf1165 (patch)
treed9dace9156a38f83ed94e08b30c195848599d826
parent0062ea0fd601c21f5c7b0d9bd1147fe216010c31 (diff)
linux-aio: poll ring for completions
The Linux AIO userspace ABI includes a ring that is shared with the kernel. This allows userspace programs to process completions without system calls. Add an AioContext poll handler to check for completions in the ring. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-6-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--block/linux-aio.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 69c4ed52ca..03ab741d37 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -255,6 +255,20 @@ static void qemu_laio_completion_cb(EventNotifier *e)
}
}
+static bool qemu_laio_poll_cb(void *opaque)
+{
+ EventNotifier *e = opaque;
+ LinuxAioState *s = container_of(e, LinuxAioState, e);
+ struct io_event *events;
+
+ if (!io_getevents_peek(s->ctx, &events)) {
+ return false;
+ }
+
+ qemu_laio_process_completions_and_submit(s);
+ return true;
+}
+
static void laio_cancel(BlockAIOCB *blockacb)
{
struct qemu_laiocb *laiocb = (struct qemu_laiocb *)blockacb;
@@ -448,7 +462,8 @@ void laio_attach_aio_context(LinuxAioState *s, AioContext *new_context)
s->aio_context = new_context;
s->completion_bh = aio_bh_new(new_context, qemu_laio_completion_bh, s);
aio_set_event_notifier(new_context, &s->e, false,
- qemu_laio_completion_cb, NULL);
+ qemu_laio_completion_cb,
+ qemu_laio_poll_cb);
}
LinuxAioState *laio_init(void)