From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=45639 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PfUcf-00067I-Uq for qemu-devel@nongnu.org; Wed, 19 Jan 2011 04:46:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PfUce-0002fM-N2 for qemu-devel@nongnu.org; Wed, 19 Jan 2011 04:46:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60596) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PfUce-0002f9-FF for qemu-devel@nongnu.org; Wed, 19 Jan 2011 04:46:36 -0500 Message-ID: <4D36B34E.8070301@redhat.com> Date: Wed, 19 Jan 2011 10:47:58 +0100 From: Kevin Wolf MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 14/19] block: insert event-tap to bdrv_aio_writev() and bdrv_aio_flush(). References: <1295415904-11918-1-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> <1295415904-11918-15-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> In-Reply-To: <1295415904-11918-15-git-send-email-tamura.yoshiaki@lab.ntt.co.jp> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yoshiaki Tamura Cc: aliguori@us.ibm.com, dlaor@redhat.com, ananth@in.ibm.com, kvm@vger.kernel.org, mst@redhat.com, mtosatti@redhat.com, qemu-devel@nongnu.org, vatsa@linux.vnet.ibm.com, blauwirbel@gmail.com, ohmura.kei@lab.ntt.co.jp, avi@redhat.com, psuriset@linux.vnet.ibm.com, stefanha@linux.vnet.ibm.com Am 19.01.2011 06:44, schrieb Yoshiaki Tamura: > event-tap function is called only when it is on, and requests sent > from device emulators. > > Signed-off-by: Yoshiaki Tamura > --- > block.c | 11 +++++++++++ > 1 files changed, 11 insertions(+), 0 deletions(-) > > diff --git a/block.c b/block.c > index ff2795b..85bd8b8 100644 > --- a/block.c > +++ b/block.c > @@ -28,6 +28,7 @@ > #include "block_int.h" > #include "module.h" > #include "qemu-objects.h" > +#include "event-tap.h" > > #ifdef CONFIG_BSD > #include > @@ -2111,6 +2112,11 @@ BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, > if (bdrv_check_request(bs, sector_num, nb_sectors)) > return NULL; > > + if (bs->device_name && event_tap_is_on()) { > + return event_tap_bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, > + cb, opaque); > + } > + > if (bs->dirty_bitmap) { > blk_cb_data = blk_dirty_cb_alloc(bs, sector_num, nb_sectors, cb, > opaque); Just noticed the context here... Does this patch break block migration when event-tap is on? Another question that came to my mind is if we really hook everything we need. I think we'll need to have a hook in bdrv_flush as well. I don't know if you do hook qemu_aio_flush and friends - does a call cause event-tap to flush its queue? If not, a call to qemu_aio_flush might hang qemu because it's waiting for requests to complete which are actually stuck in the event-tap queue. Kevin