Re: power management experiences with joyride-1572
On 26/01/08 21:47 +, [EMAIL PROTECTED] wrote: On Fri, 25 Jan 2008, Richard A. Smith wrote: Chris Ball wrote: Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? Yes, but the software does not support this yet. See bug #4606: http://dev.laptop.org/ticket/4606 We don't *use* the southbridge RTC wakeup, but it's not strictly true that we don't support it. You can set your own wakeups easily: # rtcwake -s 120 after 30s, the laptop should suspend due to idleness after another 90s, the laptop should wake itself rtcwake is in the OLPC build already. - Chris. RTC wakeups have a chance of hitting #1835 because the EC cannot prevent the short cycle of the control line to the voltage regulator so we don't use them. Andres has discussed prohibiting RTC wakeups in kernel space but I suggested we put that in the don't do that category since he has higher priority stuff to worry about. The safe way to schedule a future wake up will be to use a EC timer. The framework for this exists but I don't have the kernel facing EC command plumbed yet. This timer will allow you to schedule a wakeup with about 10ms resolution up to 24 days in the future. what is the shortest time that a sleep (followed by a wakeup from the EC timer) can be programmed? would it make sense to hack the kernel so that if all timers are set to fire more than this far in the future it wakes a user task that can decide to sleep See also 'cpuidle' [1]. Jordan [1] - http://lwn.net/Articles/221791/ ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 24, 2008 5:12 PM, Tomeu Vizoso [EMAIL PROTECTED] wrote: On Fri, 2008-01-25 at 01:45 +0100, Ivan Krstić wrote: On Jan 25, 2008, at 1:31 AM, Frank Ch. Eigler wrote: if the all brand new XO-focused software doesn't already do this We're building a platform, and have been completely and brutally transparent about our progress. Software built on our platform will keep improving rapidly along a number of axes, power management being one, and even more rapidly if folks jump in and help us with the work. Patches welcome ;) So you may end up needing a tool that applies heuristics and overrides the CPU requests of poor programs. As an anecdote, I spend a non-trivial amount of time working in disconnected environments using battery power on my non-XO laptop, and I've been obtaining noticeable battery life gains by manually SIGSTOPping Firefox when not in use. Now, I usually have about 70-200 tabs open -- which may be an edge case, but _shouldn't_ be: programmers need to learn that when I'm not actively using their software, it shouldn't be _doing_ stuff on my machine without a very good reason. Also, lots of people in the FLOSS world are realizing that their software needs to run on small devices (mobile/embedded projects/alliances etc.). Tomeu As a former market analyst, I have observed that every year, somebody is complaining about some aspect of Linux not being ready for the world, and that every year, the community deals with it. At one time it was said that Unix couldn't support enterprise computing, and in particular serious databases. IBM and Oracle became excellent counterexamples. Linux was too hard to install. Many distros worked on it, and Ubuntu has laid that complaint to rest. Linux wasn't ready for the desktop, however well it did on servers. Now Dell and others offer Linux preinstalled. (I get mine from Linux Certified in Sunnyvale.) This, that, and the other are wrong with XO software. But they soon won't be. This is a much more general phenomenon. At one time you couldn't get compilers to produce relocatable code. (Really) At about that time, you couldn't get a hard drive for a personal computer. Time marches on, and so does the state of the art. The Linux world is discovering time and space bloat. Since the solutions are shared, they will be taken up at a rate astonishing to those in the commercial world. BTW, thanks, Ivan and everybody. I'm sending people your way at every opportunity. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel -- Edward Cherlin End Poverty at a Profit by teaching children business http://www.EarthTreasury.org/ The best way to predict the future is to invent it.--Alan Kay ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
Chris Ball wrote: Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? Yes, but the software does not support this yet. See bug #4606: http://dev.laptop.org/ticket/4606 We don't *use* the southbridge RTC wakeup, but it's not strictly true that we don't support it. You can set your own wakeups easily: # rtcwake -s 120 after 30s, the laptop should suspend due to idleness after another 90s, the laptop should wake itself rtcwake is in the OLPC build already. - Chris. RTC wakeups have a chance of hitting #1835 because the EC cannot prevent the short cycle of the control line to the voltage regulator so we don't use them. Andres has discussed prohibiting RTC wakeups in kernel space but I suggested we put that in the don't do that category since he has higher priority stuff to worry about. The safe way to schedule a future wake up will be to use a EC timer. The framework for this exists but I don't have the kernel facing EC command plumbed yet. This timer will allow you to schedule a wakeup with about 10ms resolution up to 24 days in the future. -- Richard Smith [EMAIL PROTECTED] One Laptop Per Child ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
Chris Ball [EMAIL PROTECTED] writes: [...] In the future, we can imagine setting wakeups programmatically, with the help of the Linux dynamic ticks implementation and the cpuidle framework -- if Frank's sugar clock has a pending wakeup in 60 seconds to update the minute hand of the clock, we can set a wakeup for +59s before going to sleep. This is a long-term feature, though. To what extent do folks know what olpc userspace is doing in its idle moments? If there is not much junk system call traffic, one could imagine a tool that monitors the processes, and when it finds that they're all voluntarily sleeping for long enough, it could schedule an early suspend and a later automatic resume. i.e., if sugar clock is doing sleep(60), but other processes are blocked on I/O, this tool could run rtcwakeup 60; echo mem /proc/.../suspend). - FChE ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 24, 2008, at 5:21 PM, Chris Ball wrote: The computer's going to be turned off a lot of the time, even when it doesn't look to you like it's obviously off, and that's just something people writing software for the XO will have to change the way they program for. I'm not yet sure how reasonable this answer is. :) FWIW, I think it's the only reasonable answer. -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 25, 2008, at 1:31 AM, Frank Ch. Eigler wrote: if the all brand new XO-focused software doesn't already do this We're building a platform, and have been completely and brutally transparent about our progress. Software built on our platform will keep improving rapidly along a number of axes, power management being one, and even more rapidly if folks jump in and help us with the work. Patches welcome ;) So you may end up needing a tool that applies heuristics and overrides the CPU requests of poor programs. As an anecdote, I spend a non-trivial amount of time working in disconnected environments using battery power on my non-XO laptop, and I've been obtaining noticeable battery life gains by manually SIGSTOPping Firefox when not in use. Now, I usually have about 70-200 tabs open -- which may be an edge case, but _shouldn't_ be: programmers need to learn that when I'm not actively using their software, it shouldn't be _doing_ stuff on my machine without a very good reason. -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 25, 2008 2:12 PM, Tomeu Vizoso [EMAIL PROTECTED] wrote: Also, lots of people in the FLOSS world are realizing that their software needs to run on small devices (mobile/embedded projects/alliances etc.). OLPC and powertop are making that very visible, and people are learning/reacting pretty well. Within a few weeks of powertop being released, the worst offenders in most distros had been fixed -- I was amazed. The fixes took a while to percolate, but on a current linux distro, laptop gets a lot more battery life (~50%) than 1 year ago now. Alas, memory use is a harder one... martin ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 25, 2008, at 1:54 AM, Frank Ch. Eigler wrote: Please don't interpret this concern as a criticism of what's been accomplished. I didn't. My point was that you shouldn't yet judge too much from the software we ship not behaving as well as it should about power management. That's exactly the sort of heuristic that an XO power boss tool could apply. A tool with such heuristics may well be easier to construct than fixes for all of userspace. Certainly, though I suspect we'll also end up providing nicer ways for platform-aware programs to perform savings in tandem with Sugar. -- Ivan Krstić [EMAIL PROTECTED] | http://radian.org ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
power management experiences with joyride-1572
Hi - I've been dabbling with joyride-1572 on a g1g1 laptop for a day or few, and have noticed the suspend feature kick in after a few seconds of apparent inactivity. I have some questions about whether some specific experiences with this are expected: - that a resume operation begins only with a keyboard/touchpad input, and takes 1-2 seconds for interactiveness to return? - that running programs such as the sugar clock widget, or programs running in the sugar terminal, all freeze during the suspend? - that if one switches to the text console (C-A-F1), one observes the backlight intensity oscillate up down with about a 10s interval, despite ongoing keyboard input? - that power consumption during the awake mode has not significantly fallen since build-650 or -653, leading to a ~3 hour battery endurance for light continuous web browsing / terminal usage? Thanks! - FChE ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
Hi Frank, Hi - I've been dabbling with joyride-1572 on a g1g1 laptop for a day or few, and have noticed the suspend feature kick in after a few seconds of apparent inactivity. I have some questions about whether some specific experiences with this are expected: - that a resume operation begins only with a keyboard/touchpad input, and takes 1-2 seconds for interactiveness to return? Yes, the resume operation is triggered by user input, or a wireless packet addressed to the host (or some battery-related events). It can't be triggered by anything in software unless that's organized ahead of time; the CPU is turned off completely in the suspend mode. We're going to be spending a lot of effort on decreasing that resume time. We've measured it at 280ms with USB and some other drivers turned off, but as you say we're above 1 second with the current setup. We need to perform a mix of: * optimizing driver resume * parallelizing driver resume * delaying driver resume until the device is needed wherever possible until we're back around the first number. So far we've been working on making it work rather than making it fast; that will start to change with our next release. - that running programs such as the sugar clock widget, or programs running in the sugar terminal, all freeze during the suspend? Correct. Note that if a program running in the sugar terminal is using non-trivial CPU, it will inhibit suspend by doing so; an automatic suspend should never happen while a compile is underway, for example. When in suspend, (approximately) everything except the screen/wireless is turned off, hence the freeze. This is why we avoid such constantly-updating applets on the sugar home screen. - that if one switches to the text console (C-A-F1), one observes the backlight intensity oscillate up down with about a 10s interval, despite ongoing keyboard input? That's a bug, since fixed in later builds. - that power consumption during the awake mode has not significantly fallen since build-650 or -653, leading to a ~3 hour battery endurance for light continuous web browsing / terminal usage? Correct, we haven't changed power consumption while everything is turned on. We're working instead on turning a lot of things off where possible. I'd be very interested to hear real-life experiences of battery life with the mix of awake and asleep modes currently present in the Joyride build. I'd also be interested in opinions on the timeouts I've chosen for the idle-suspend mode -- currently we suspend after 30 seconds of user input idleness, if the CPU is also idle. Thanks, - Chris. -- Chris Ball [EMAIL PROTECTED] ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Wed, 2008-01-23 at 11:47 -0800, Hal Murray wrote: Yes, the resume operation is triggered by user input, or a wireless packet addressed to the host (or some battery-related events). It can't be triggered by anything in software unless that's organized ahead of time; the CPU is turned off completely in the suspend mode. What does organized ahead of time mean? Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? Yes, but the software does not support this yet. See bug #4606: http://dev.laptop.org/ticket/4606 ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
On Jan 23, 2008 2:47 PM, Hal Murray [EMAIL PROTECTED] wrote: Yes, the resume operation is triggered by user input, or a wireless packet addressed to the host (or some battery-related events). It can't be triggered by anything in software unless that's organized ahead of time; the CPU is turned off completely in the suspend mode. What does organized ahead of time mean? Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? snip On most hardware, yes. It is more of a clock than a timer. You can preset a specific time to wake-up the machine (say 0900 when you are showing up at work). I can't say for certain that the XO-1 has this ability though. ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
Hi, What does organized ahead of time mean? Setting a wakeup timer before going to sleep. Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? There are two timers left running. There is the Geode southbridge RTC, which can set a wakeup to one-second resolution (but not sub-second) using the standard Linux RTC device interface. There is also the EC, which has just gained the same ability but without the limitation of having to set wakeups on second boundaries. I suspect that we will start to use the EC timer in the next feature release of the software. In the future, we can imagine setting wakeups programmatically, with the help of the Linux dynamic ticks implementation and the cpuidle framework -- if Frank's sugar clock has a pending wakeup in 60 seconds to update the minute hand of the clock, we can set a wakeup for +59s before going to sleep. This is a long-term feature, though. - Chris. -- Chris Ball [EMAIL PROTECTED] ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: power management experiences with joyride-1572
Hi, Can I wake up 10 seconds from now? Is there a timer in any of the hardware that is left running? Yes, but the software does not support this yet. See bug #4606: http://dev.laptop.org/ticket/4606 We don't *use* the southbridge RTC wakeup, but it's not strictly true that we don't support it. You can set your own wakeups easily: # rtcwake -s 120 after 30s, the laptop should suspend due to idleness after another 90s, the laptop should wake itself rtcwake is in the OLPC build already. - Chris. -- Chris Ball [EMAIL PROTECTED] ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
