From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45195) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3hdz-0005vL-L9 for qemu-devel@nongnu.org; Tue, 01 Dec 2015 04:54:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a3hdy-0002ty-Sq for qemu-devel@nongnu.org; Tue, 01 Dec 2015 04:54:43 -0500 Date: Tue, 1 Dec 2015 10:54:36 +0100 From: Kevin Wolf Message-ID: <20151201095436.GC6527@noname.str.redhat.com> References: <1448962590-2842-1-git-send-email-famz@redhat.com> <1448962590-2842-2-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448962590-2842-2-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [PATCH 1/3] block: Don't wait serialising for non-COR read requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Jeff Cody , qemu-block@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi Am 01.12.2015 um 10:36 hat Fam Zheng geschrieben: > The assertion problem was noticed in 06c3916b35a, but it wasn't > completely fixed, because even though the req is not marked as > serialising, it still gets serialised by wait_serialising_requests > against other serialising requests, which could lead to the same > assertion failure. > > Fix it by even more explicitly skipping the serialising for this > specific case. > > Signed-off-by: Fam Zheng And this, my friends, is another example why read/write notifiers are wrong and should die sooner rather than later. Kevin