From 5e77aaa0d7d2f4ceaa4fcaf50f3a26d5150f34a6 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 7 Jul 2010 19:44:22 +0300 Subject: [PATCH] QEMUFileBuffered: indicate that we're ready when the underlying file is ready QEMUFileBuffered stops writing when the underlying QEMUFile is not ready, and tells its producer so. However, when the underlying QEMUFile becomes ready, it neglects to pass that information along, resulting in stoppage of all data until the next tick (a tenths of a second). Usually this doesn't matter, because most QEMUFiles used with QEMUFileBuffered are almost always ready, but in the case of exec: migration this is not true, due to the small pipe buffers used to connect to the target process. The result is very slow migration. Fix by detecting the readiness notification and propagating it. The detection is a little ugly since QEMUFile overloads put_buffer() to send it, but that's the suject for a different patch. Signed-off-by: Avi Kivity Signed-off-by: Anthony Liguori --- buffered_file.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/buffered_file.c b/buffered_file.c index 54dc6c29ba..a79264f451 100644 --- a/buffered_file.c +++ b/buffered_file.c @@ -156,6 +156,14 @@ static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, in offset = size; } + if (pos == 0 && size == 0) { + DPRINTF("file is ready\n"); + if (s->bytes_xfer <= s->xfer_limit) { + DPRINTF("notifying client\n"); + s->put_ready(s->opaque); + } + } + return offset; } -- 2.11.0