From 3407de572b19a9721d3a107fe5856ab3c40b6f52 Mon Sep 17 00:00:00 2001 From: Roman Pen Date: Tue, 19 Jul 2016 14:27:42 +0200 Subject: [PATCH] linux-aio: split processing events function Prepare processing events function to be called from ioq_submit(), thus split function on two parts: the first harvests completed IO requests, the second submits pending requests. Signed-off-by: Roman Pen Message-id: 1468931263-32667-3-git-send-email-roman.penyaev@profitbricks.com Cc: Stefan Hajnoczi Cc: Paolo Bonzini Cc: qemu-devel@nongnu.org Signed-off-by: Stefan Hajnoczi --- block/linux-aio.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/block/linux-aio.c b/block/linux-aio.c index 62ee1ea8a5..252ebef6ae 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -180,20 +180,20 @@ io_getevents_advance_and_peek(io_context_t ctx, return io_getevents_peek(ctx, events); } -/* The completion BH fetches completed I/O requests and invokes their - * callbacks. +/** + * qemu_laio_process_completions: + * @s: AIO state + * + * Fetches completed I/O requests and invokes their callbacks. * * The function is somewhat tricky because it supports nested event loops, for * example when a request callback invokes aio_poll(). In order to do this, - * the completion events array and index are kept in LinuxAioState. The BH - * reschedules itself as long as there are completions pending so it will - * either be called again in a nested event loop or will be called after all - * events have been completed. When there are no events left to complete, the - * BH returns without rescheduling. + * indices are kept in LinuxAioState. Function schedules BH completion so it + * can be called again in a nested event loop. When there are no events left + * to complete the BH is being canceled. */ -static void qemu_laio_completion_bh(void *opaque) +static void qemu_laio_process_completions(LinuxAioState *s) { - LinuxAioState *s = opaque; struct io_event *events; /* Reschedule so nested event loops see currently pending completions */ @@ -222,18 +222,29 @@ static void qemu_laio_completion_bh(void *opaque) * own `for` loop. If we are the last all counters droped to zero. */ s->event_max = 0; s->event_idx = 0; +} +static void qemu_laio_process_completions_and_submit(LinuxAioState *s) +{ + qemu_laio_process_completions(s); if (!s->io_q.plugged && !QSIMPLEQ_EMPTY(&s->io_q.pending)) { ioq_submit(s); } } +static void qemu_laio_completion_bh(void *opaque) +{ + LinuxAioState *s = opaque; + + qemu_laio_process_completions_and_submit(s); +} + static void qemu_laio_completion_cb(EventNotifier *e) { LinuxAioState *s = container_of(e, LinuxAioState, e); if (event_notifier_test_and_clear(&s->e)) { - qemu_laio_completion_bh(s); + qemu_laio_process_completions_and_submit(s); } }