From 65c1b5b622d09044af3f872240d65e7343f6f83e Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 27 Oct 2016 12:49:06 +0200 Subject: iothread: release AioContext around aio_poll This is the first step towards having fine-grained critical sections in dataplane threads, which will resolve lock ordering problems between address_space_* functions (which need the BQL when doing MMIO, even after we complete RCU-based dispatch) and the AioContext. Because AioContext does not use contention callbacks anymore, the unit test has to be changed. Previously applied as a0710f7995f914e3044e5899bd8ff6c43c62f916 and then reverted. Reviewed-by: Fam Zheng Signed-off-by: Paolo Bonzini Message-Id: <1477565348-5458-19-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng --- async.c | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-) (limited to 'async.c') diff --git a/async.c b/async.c index fb37b031cb..27db7726e1 100644 --- a/async.c +++ b/async.c @@ -107,8 +107,8 @@ int aio_bh_poll(AioContext *ctx) * aio_notify again if necessary. */ if (atomic_xchg(&bh->scheduled, 0)) { - /* Idle BHs and the notify BH don't count as progress */ - if (!bh->idle && bh != ctx->notify_dummy_bh) { + /* Idle BHs don't count as progress */ + if (!bh->idle) { ret = 1; } bh->idle = 0; @@ -260,7 +260,6 @@ aio_ctx_finalize(GSource *source) { AioContext *ctx = (AioContext *) source; - qemu_bh_delete(ctx->notify_dummy_bh); thread_pool_free(ctx->thread_pool); #ifdef CONFIG_LINUX_AIO @@ -346,19 +345,6 @@ static void aio_timerlist_notify(void *opaque) aio_notify(opaque); } -static void aio_rfifolock_cb(void *opaque) -{ - AioContext *ctx = opaque; - - /* Kick owner thread in case they are blocked in aio_poll() */ - qemu_bh_schedule(ctx->notify_dummy_bh); -} - -static void notify_dummy_bh(void *opaque) -{ - /* Do nothing, we were invoked just to force the event loop to iterate */ -} - static void event_notifier_dummy_cb(EventNotifier *e) { } @@ -386,11 +372,9 @@ AioContext *aio_context_new(Error **errp) #endif ctx->thread_pool = NULL; qemu_mutex_init(&ctx->bh_lock); - rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx); + rfifolock_init(&ctx->lock, NULL, NULL); timerlistgroup_init(&ctx->tlg, aio_timerlist_notify, ctx); - ctx->notify_dummy_bh = aio_bh_new(ctx, notify_dummy_bh, NULL); - return ctx; fail: g_source_destroy(&ctx->source); -- cgit 1.4.1