From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36267) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aOkH3-00088W-QF for qemu-devel@nongnu.org; Thu, 28 Jan 2016 05:58:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aOkH2-00066Y-TZ for qemu-devel@nongnu.org; Thu, 28 Jan 2016 05:58:01 -0500 Date: Thu, 28 Jan 2016 18:57:51 +0800 From: Fam Zheng Message-ID: <20160128105751.GA28015@ad.usersys.redhat.com> References: <1453964571-23016-1-git-send-email-famz@redhat.com> <1453964571-23016-3-git-send-email-famz@redhat.com> <56A9DAEE.7060206@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56A9DAEE.7060206@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] blockjob: Fix hang in block_job_finish_sync List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Kevin Wolf , stefanha@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org, mreitz@redhat.com On Thu, 01/28 10:10, Paolo Bonzini wrote: > > > On 28/01/2016 08:02, Fam Zheng wrote: > > > > This is because the aio_poll() only processes the AIO context of bs > > which has no more work to do, while the main loop BH that is scheduled > > for setting the job->completed flag is never processed. > > > > Fix this by adding a "ctx" pointer in BlockJob structure, to track which > > context to poll for the block job to make progress. Its value is set to > > the BDS context at block job creation, until > > block_job_coroutine_complete() is called by the block job coroutine. > > After that point, the block job's work is deferred to main loop BH. > > > > Signed-off-by: Fam Zheng > > --- > > blockjob.c | 4 +++- > > include/block/blockjob.h | 2 ++ > > 2 files changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/blockjob.c b/blockjob.c > > index 4b16720..4ea1ce0 100644 > > --- a/blockjob.c > > +++ b/blockjob.c > > @@ -74,6 +74,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, > > job->opaque = opaque; > > job->busy = true; > > job->refcnt = 1; > > + job->ctx = bdrv_get_aio_context(bs); > > Can the context change if dataplane is started/stopped in the middle of > a job? (For example if you start migration). Perhaps job->ctx == NULL > could mean "use bdrv_get_aio_context(bs)". Yes, that's a good idea. Fam