Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752036AbbD3RX7 (ORCPT ); Thu, 30 Apr 2015 13:23:59 -0400 Received: from mail-lb0-f176.google.com ([209.85.217.176]:33034 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751086AbbD3RX5 (ORCPT ); Thu, 30 Apr 2015 13:23:57 -0400 MIME-Version: 1.0 X-Originating-IP: [2620:0:1000:157d:59b5:7dd4:5c20:bbb] In-Reply-To: References: <1413881397.30379.7.camel@hadess.net> <1430411117.3945.2.camel@hadess.net> Date: Thu, 30 Apr 2015 10:23:56 -0700 Message-ID: Subject: Re: A desktop environment[1] kernel wishlist From: Olof Johansson To: John Stultz Cc: Bastien Nocera , "Rafael J. Wysocki" , Linux Kernel Mailing List , snanda@chromium.org, Chirantan Ekbote Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2696 Lines: 68 Hi, On Thu, Apr 30, 2015 at 10:10 AM, John Stultz wrote: > On Thu, Apr 30, 2015 at 9:25 AM, Bastien Nocera wrote: >> On Tue, 2014-10-21 at 10:04 -0700, John Stultz wrote: >>> On Tue, Oct 21, 2014 at 1:49 AM, Bastien Nocera >>> wrote: >>> > Hey, >>> > >>> > GNOME has had discussions with kernel developers in the past, and, >>> > fortunately, in some cases we were able to make headway. >>> > >>> > There are however a number of items that we still don't have >>> > solutions >>> > for, items that kernel developers might not realise we'd like to >>> > rely >>> > on, or don't know that we'd make use of if merged. >>> > >>> > I've posted this list at: >>> > https://wiki.gnome.org/BastienNocera/KernelWishlist >>> > >>> > Let me know on-list or off-list if you have any comments about >>> > those, so >>> > I can update the list. >>> >>> As for: 'Export of "wake reason" when the system wakes up (rtc alarm, >>> lid open, etc.) and wakealarm (/sys/class/rtc/foo/wakealarm) >>> documentation' >>> >>> Can you expand more on the rational for the need here? Is this for UI >>> for power debugging, or something else? >> >> This is pretty much what I had in mind: >> https://www.chromium.org/chromium-os/chromiumos-design-docs/lucid-sleep >> >> I guess I didn't make myself understood. > > My, admittedly quick skim, of that design document seems to suggest > that lucid sleep would be a new kernel state. That would keep the > kernel in charge of determining the state transitions (ie: > SUSPEND-(alarm)->LUCID-(wakelock > release)->SUSPEND-(alarm)->LUCID-(power-button)->AWAKE). Then it seems > userspace would be able to query the current state. This avoids some > of the races I was concerned with trying to detect which irq woke us > from suspend from userspace. > > That said, the Power Manager section in that document sounds a little > racy as it seems to rely on asking userspace if suspend is ok, rather > then using userspace wakelocks, so I'm not sure how well baked this > doc is. > > Olof: Can you comment on who's working on that design doc? Also the > discussion around using freezing cgroups separately to distinguish > between lucid and awake is interesting, but I wonder if we need to > make wakeup_sources/wakelocks cgroup aware, or has that already been > done? Sameer and Chirantan have both been deeply involved in that project, adding them on cc here. -Olof -- 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/