From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=46325 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OWYWT-0005Vs-7y for qemu-devel@nongnu.org; Wed, 07 Jul 2010 13:35:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OWYWR-0004lc-A3 for qemu-devel@nongnu.org; Wed, 07 Jul 2010 13:35:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35164) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OWYWR-0004lO-3C for qemu-devel@nongnu.org; Wed, 07 Jul 2010 13:34:59 -0400 From: Avi Kivity Date: Wed, 7 Jul 2010 19:44:22 +0300 Message-Id: <1278521062-13795-1-git-send-email-avi@redhat.com> Subject: [Qemu-devel] [PATCH] QEMUFileBuffered: indicate that we're ready when the underlying file is ready List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori , qemu-devel@nongnu.org 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 --- buffered_file.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/buffered_file.c b/buffered_file.c index 54dc6c2..a79264f 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; } -- 1.7.1