Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933238AbaGURR5 (ORCPT ); Mon, 21 Jul 2014 13:17:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42189 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932977AbaGURRz (ORCPT ); Mon, 21 Jul 2014 13:17:55 -0400 Message-ID: <1405963056.20886.9.camel@dcbw.local> Subject: Re: [PATCH] Hyperv: Trigger DHCP renew after host hibernation From: Dan Williams To: Lennart Poettering Cc: "Yue Zhang (OSTC DEV)" , Tom Gundersen , netdev , "driverdev-devel@linuxdriverproject.org" , LKML , Greg KH , "olaf@aepfle.de" , "jasowang@redhat.com" , David Miller , Haiyang Zhang , KY Srinivasan , Thomas Shao , Dexuan Cui Date: Mon, 21 Jul 2014 12:17:36 -0500 In-Reply-To: <20140721131154.GA23385@tango.0pointer.de> References: <1405680903-28176-1-git-send-email-yuezha@microsoft.com> <20140721131154.GA23385@tango.0pointer.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-07-21 at 15:11 +0200, Lennart Poettering wrote: > On Mon, 21.07.14 10:21, Yue Zhang (OSTC DEV) (yuezha@microsoft.com) wrote: > > > Some network monitoring daemon, like ifplugd has a deferring mechanism. > > When it detects carriers is offline, it doesn't trigger DHCP renew immediately. > > Instead it will wait for another 5 seconds to check whether carrier is back to > > online status. In that case, it will avoid renew DHCP lease. > > ifplugd doesn't renew DHCP leases anyway, one of the scripts it invokes > does. > > ifplugd is obsolete software. I wrote it more than 10 years ago, and > haven't really updated it since. it's sounds seriously wrong to add > multi-second waits to the kernel just to make this crappy, obsolete > software work. > > Please fix this properly, and work with the PM guys, so that we get a > sane userspace how the kernel can notify userspace about > suspends/hibernations triggered from the outside, so that userspace > daemons can subscribe to that and then refresh the DHCP leases on their > own. Yeah, like I've said before, there have been other cases where a "hey, my L3 address might be wrong now, so please confirm it" message would be useful. Carrier on/off doesn't necessarily mean that, but even if it did, the off interval is a really bad mechanism for that too. So I'd really like some kind of event for this that's distinct from carrier that userspace could use. Dan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/