From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40018) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNfxY-0007Ti-6e for qemu-devel@nongnu.org; Thu, 14 Jul 2016 08:41:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bNfxV-0004lc-0z for qemu-devel@nongnu.org; Thu, 14 Jul 2016 08:41:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56517) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bNfxU-0004lY-RI for qemu-devel@nongnu.org; Thu, 14 Jul 2016 08:41:40 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F0AF011BB45 for ; Thu, 14 Jul 2016 12:41:39 +0000 (UTC) References: <1467065523-13881-1-git-send-email-thuth@redhat.com> From: Thomas Huth Message-ID: <6ee35ae0-9a76-b6ab-be9c-1b28a4c38ab7@redhat.com> Date: Thu, 14 Jul 2016 14:41:38 +0200 MIME-Version: 1.0 In-Reply-To: <1467065523-13881-1-git-send-email-thuth@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] virtio: Tell the user what went wrong when event_notifier_init failed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , qemu-devel@nongnu.org On 28.06.2016 00:12, Thomas Huth wrote: > event_notifier_init() can fail in real life, for example when there > are not enough open file handles available (EMFILE) when using a lot > of devices. So instead of leaving the average user with a cryptic > error number only, print out a proper error message with strerror() > instead, so that the user has a better way to figure out what is > going on and that using "ulimit -n" might help here for example. > > Signed-off-by: Thomas Huth > --- > hw/virtio/virtio-bus.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c > index 1313760..08e38fb 100644 > --- a/hw/virtio/virtio-bus.c > +++ b/hw/virtio/virtio-bus.c > @@ -164,7 +164,8 @@ static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus, > if (assign) { > r = event_notifier_init(notifier, 1); > if (r < 0) { > - error_report("%s: unable to init event notifier: %d", __func__, r); > + error_report("%s: unable to init event notifier: %s (%d)", > + __func__, strerror(-r), r); > return r; > } > virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler); > ping? Thomas