From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37686) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlAGG-00069e-1N for qemu-devel@nongnu.org; Fri, 16 May 2014 01:00:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WlAGB-0005Lc-Ez for qemu-devel@nongnu.org; Fri, 16 May 2014 01:00:47 -0400 Received: from [2a03:4000:1::4e2f:c7ac:d] (port=41701 helo=v220110690675601.yourvserver.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlAGB-0005LP-9F for qemu-devel@nongnu.org; Fri, 16 May 2014 01:00:43 -0400 Message-ID: <53759B68.303@weilnetz.de> Date: Fri, 16 May 2014 07:00:24 +0200 From: Stefan Weil MIME-Version: 1.0 References: <1399538830-4443-1-git-send-email-s.vorobiov@samsung.com> <20140509185740.GA28528@stefanha-thinkpad.redhat.com> In-Reply-To: <20140509185740.GA28528@stefanha-thinkpad.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5] glib: fix g_poll early timeout on windows List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , Stanislav Vorobiov Cc: alex@alex.org.uk, sangho1206.park@samsung.com, qemu-devel@nongnu.org, stefanha@redhat.com, syeon.hwang@samsung.com, pbonzini@redhat.com Am 09.05.2014 20:57, schrieb Stefan Hajnoczi: > On Thu, May 08, 2014 at 12:47:10PM +0400, Stanislav Vorobiov wrote: >> From: Sangho Park >> >> g_poll has a problem on Windows when using >> timeouts < 10ms, in glib/gpoll.c: >> >> /* If not, and we have a significant timeout, poll again with >> * timeout then. Note that this will return indication for only >> * one event, or only for messages. We ignore timeouts less than >> * ten milliseconds as they are mostly pointless on Windows, the >> * MsgWaitForMultipleObjectsEx() call will timeout right away >> * anyway. >> */ >> if (retval == 0 && (timeout == INFINITE || timeout >= 10)) >> retval = poll_rest (poll_msgs, handles, nhandles, fds, nfds, timeout); >> >> so whenever g_poll is called with timeout < 10ms it does >> a quick poll instead of wait, this causes significant performance >> degradation of QEMU, thus we should use WaitForMultipleObjectsEx >> directly >> >> Signed-off-by: Stanislav Vorobiov >> --- >> include/glib-compat.h | 9 +++- >> util/oslib-win32.c | 112 +++++++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 120 insertions(+), 1 deletion(-) > > Thanks, applied to my block tree: > https://github.com/stefanha/qemu/commits/block > > Stefan > Hi, the patch breaks hard disk i/o: a 64 bit executable built with MinGW-w64 will no longer boot a ReactOS image (BIOS fails to detect a bootable disk). Booting a Linux CDROM seems to work and is indeed much faster. Regards Stefan