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| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-04-07 18:33:34 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2016-05-12 15:22:07 +0200 |
| commit | 6b98bd649520d07df4d1b7a0a54ac73bf178519c (patch) | |
| tree | 22924e241859dcc57d55fdb1d71c8f4220313633 /block/linux-aio.c | |
| parent | ce0f141259f06fd77fde2519cc352618ad797ce2 (diff) | |
| download | qemu-6b98bd649520d07df4d1b7a0a54ac73bf178519c.tar.gz qemu-6b98bd649520d07df4d1b7a0a54ac73bf178519c.tar.bz2 qemu-6b98bd649520d07df4d1b7a0a54ac73bf178519c.zip | |
block: plug whole tree at once, introduce bdrv_io_unplugged_begin/end
Extract the handling of io_plug "depth" from linux-aio.c and let the
main bdrv_drain loop do nothing but wait on I/O.
Like the two newly introduced functions, bdrv_io_plug and bdrv_io_unplug
now operate on all children. The visit order is now symmetrical between
plug and unplug, making it possible for formats to implement plug/unplug.
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/linux-aio.c')
| -rw-r--r-- | block/linux-aio.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/block/linux-aio.c b/block/linux-aio.c index 805757e02e..102bf928af 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -220,19 +220,16 @@ void laio_io_plug(BlockDriverState *bs, void *aio_ctx) { struct qemu_laio_state *s = aio_ctx; - s->io_q.plugged++; + assert(!s->io_q.plugged); + s->io_q.plugged = 1; } -void laio_io_unplug(BlockDriverState *bs, void *aio_ctx, bool unplug) +void laio_io_unplug(BlockDriverState *bs, void *aio_ctx) { struct qemu_laio_state *s = aio_ctx; - assert(s->io_q.plugged > 0 || !unplug); - - if (unplug && --s->io_q.plugged > 0) { - return; - } - + assert(s->io_q.plugged); + s->io_q.plugged = 0; if (!s->io_q.blocked && !QSIMPLEQ_EMPTY(&s->io_q.pending)) { ioq_submit(s); } |