From 845ca10dd089b4e48f0a79bad005fb30eb77584e Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 9 Jul 2014 11:53:01 +0200 Subject: AioContext: take bottom halves into account when computing aio_poll timeout Right now, QEMU invokes aio_bh_poll before the "poll" phase of aio_poll. It is simpler to do it afterwards and skip the "poll" phase altogether when the OS-dependent parts of AioContext are invoked from GSource. This way, AioContext behaves more similarly when used as a GSource vs. when used as stand-alone. As a start, take bottom halves into account when computing the poll timeout. If a bottom half is ready, do a non-blocking poll. As a side effect, this makes idle bottom halves work with aio_poll; an improvement, but not really an important one since they are deprecated. Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi --- async.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) (limited to 'async.c') diff --git a/async.c b/async.c index 34af0b25ca..09e09c6526 100644 --- a/async.c +++ b/async.c @@ -152,39 +152,43 @@ void qemu_bh_delete(QEMUBH *bh) bh->deleted = 1; } -static gboolean -aio_ctx_prepare(GSource *source, gint *timeout) +int64_t +aio_compute_timeout(AioContext *ctx) { - AioContext *ctx = (AioContext *) source; + int64_t deadline; + int timeout = -1; QEMUBH *bh; - int deadline; - /* We assume there is no timeout already supplied */ - *timeout = -1; for (bh = ctx->first_bh; bh; bh = bh->next) { if (!bh->deleted && bh->scheduled) { if (bh->idle) { /* idle bottom halves will be polled at least * every 10ms */ - *timeout = 10; + timeout = 10000000; } else { /* non-idle bottom halves will be executed * immediately */ - *timeout = 0; - return true; + return 0; } } } - deadline = qemu_timeout_ns_to_ms(timerlistgroup_deadline_ns(&ctx->tlg)); + deadline = timerlistgroup_deadline_ns(&ctx->tlg); if (deadline == 0) { - *timeout = 0; - return true; + return 0; } else { - *timeout = qemu_soonest_timeout(*timeout, deadline); + return qemu_soonest_timeout(timeout, deadline); } +} - return false; +static gboolean +aio_ctx_prepare(GSource *source, gint *timeout) +{ + AioContext *ctx = (AioContext *) source; + + /* We assume there is no timeout already supplied */ + *timeout = qemu_timeout_ns_to_ms(aio_compute_timeout(ctx)); + return *timeout == 0; } static gboolean -- cgit v1.2.3-59-g8ed1b