Linux 3.15 Will Suspend & Resume Much Faster

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Linux 3.15 Will Suspend & Resume Much Faster

Posted by Soulskill on Saturday April 12, 2014 @08:48AM from the cutting-into-my-foot-tapping-time dept.

An anonymous reader writes "The Linux 3.15 kernel now in its early life will be able to suspend and resume much faster than previous versions of the Linux kernel. A few days ago we saw ACPI and Power Management updates that enable asynchronous threads for more suspend and resume callbacks. Carrying out more async operations leads to reduced time for the system suspend and then resuming. According to one developer, it was about an 80% time savings within one of the phases. On Friday, work was merged that ensured the kernel is no longer blocked by waiting for ATA devices to resume. Multiple ATA devices can be woken up simultaneously, and any ATA commands for the device(s) will be queued until they have powered up. According to an 01.org blog post on the ATA/SCSI resume optimization patches, when tested on three Intel Linux systems the resume time was between 7x and 12x faster (not including the latest ACPI/PM S&R optimizations)."

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Caution by arth1 · 2014-04-12 08:57 · Score: 5, Insightful

There's a reason why RAID controllers tend to wake up drives sequentially. The power load of waking up 20 hard drives at the same time can be tremendous compared to the load when they're all spinning and purring. So you don't do that.
So I hope that power draw is taken into account, and that there will be options to limit the number of devices woken up simultaneously.
1. Re:Caution by K.+S.+Kyosuke · 2014-04-12 09:14 · Score: 5, Insightful
  
  Something tells me that machines with a heavily RAID-ed disk subsystem are not exactly your usual candidates for frequent power cycles.
  
  --
  Ezekiel 23:20
2. Re:Caution by Anonymous Coward · 2014-04-12 09:18 · Score: 0
  
  You've never seen a datacenter where the UPS failed?
3. Re:Caution by RulerOf · 2014-04-12 09:20 · Score: 2
  
  But what system with dozens of hard drives in it would be entering and exiting S3 constantly anyway?
  
  You might do power saving on hypervisor hosts, but on a SAN? I can't think of a scenario where it makes a lot of sense... but perhaps I'm just lacking the proper imagination :P
  
  On topic: I think this is awesome. I want to be able to suspend my machine and wake it up whenever I feel like it, with VMs shuffling around waiting for me to pick up a different tablet, or sit at a different desk. x86 has a lot of catching up to do. After all, I've gotten pretty used to putting a device "to sleep" and "waking it up" instantly. It'd be nice if my computer could do the same thing... even if it's only in spirit. Of course, an S3/4/5 is a much deeper sleep than my phone or tablet ever enters while it's powered on, AFAIK.
  
  --
  Boot Windows, Linux, and ESX over the network for free.
4. Re:Caution by SpankiMonki · 2014-04-12 09:26 · Score: 5, Informative
  
  There's a reason why RAID controllers tend to wake up drives sequentially.
  And the RAID controllers will continue to do just that. All this change does is allow the kernel to continue resuming without having to wait for the device to report that it's ready. Any commands sent to the device in the meantime are queued.
5. Re:Caution by KiloByte · 2014-04-12 09:29 · Score: 2
  
  If your UPS dies, a suspended machine is screwed just the same. There's rather little point in suspending a server: even ones that are off outside business hours are better off hibernating rather than suspending.
  
  --
  The creatures outside looked from Alt-Right to Antifa; but already it was impossible to say which was which.
6. Re:Caution by Anonymous Coward · 2014-04-12 09:36 · Score: 0
  
  I would have thought you would replace your UPS if you noticed that it was failing consistently. Or maybe change data centres if their juice is so flakey that you notice your UPS is failing so regularly you need quick suspend and resume... Or do I understand nothing at all?
7. Re:Caution by Antique+Geekmeister · 2014-04-12 09:38 · Score: 1
  
  Or a 1U server full of SSD drives, or from a decade ago full of laptop hard drives?
8. Re:Caution by Anonymous Coward · 2014-04-12 09:44 · Score: 0
  
  I think a lot.
  What you think about becoming my boss?
9. Re:Caution by smittyoneeach · 2014-04-12 09:46 · Score: 0
  
  More rare: the times the UPS was more than a brown truck with a penchant for right turns.
  
  --
  Get thee glass eyes, and, like a scurvy politician, seem to see things thou dost not.--King Lear
10. Re:Caution by Anonymous Coward · 2014-04-12 09:52 · Score: 3, Informative
  
  Consider that Linux runs on everything. It's not unlikely that there are plenty of clusters out there that suspends whole computers when the power is not needed. If they are also filled with HDDs, then that use case arises.
  I think it's a valid point, even though it's not very common.
11. Re:Caution by Anonymous Coward · 2014-04-12 10:06 · Score: 1
  
  Yes, and it matters a whole lot more to us power users with lots of data! Even with large 3TB+ hard drives, it can take lots of drives to fit all of our data. My motherboard has 6 SATA ports and I have an SATA controller with 4 extra ports. Waking up 10 drives at the same time is an extra 20A of load or so on the 12V rail. That requires a fairly solid, high quality/high current PSU (admittedly I do have that).
12. Re:Caution by Anonymous Coward · 2014-04-12 10:10 · Score: 2, Informative
  
  If it's a hardware RAID controller then the kernel should "see" a single logical device it needs to wake up, and it can leave it to the controller firmware to wake up the drives in the correct order.
13. Re:Caution by evilviper · 2014-04-12 10:42 · Score: 1
  
  There's rather little point in suspending a server:
  Those of us who do this stuff happen to disagree with you.
  
  even ones that are off outside business hours are better off hibernating rather than suspending.
  "Better off" HOW? Hibernation takes much, much longer on both ends, and the difference in power consumption between hibernate and suspend is nominal. When your cluster suddenly needs more power, you don't want to wait 10 minutes for POST, kernel booting, and copying quite a few GBytes from disk into RAM, when you can instead get up and running in a few seconds.
  
  --
  Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
14. Re:Caution by sjames · 2014-04-12 12:49 · Score: 2
  
  No, but but that one time a year when it does, it will be important to power the drives in sequence, not all at once.
  The parallel start can still help though. There is a period of time between the inrush where the platters are at about the right speed but not yet stable. That's the point where powering the next drive on would be OK.
15. Re:Caution by sjames · 2014-04-12 12:54 · Score: 3, Interesting
  
  And if it's soft RAID or a ZFS pool?
16. Re:Caution by epyT-R · 2014-04-12 13:16 · Score: 1
  
  Uh.. x86 has been able to do this for over a decade now.. It's linux that's catching up. It's power management hasn't been that great.
17. Re:Caution by arth1 · 2014-04-12 13:19 · Score: 2
  
  But what system with dozens of hard drives in it would be entering and exiting S3 constantly anyway?
  It doesn't have to be constantly. Once is enough.
  And you don't even need dozens of hard drives. Workstations with RAID 10 aren't all that uncommon. Being able to not have all drives spin up all at the same time would be beneficial, especially as the power supply gets older - even after as little as a year of constant use, the ability to handle high loads can easily be half or less of what it was when new.
  While a motherboard BIOS will take care of spinning up drives sequentially at boot, it won't help for suspend.
  So yes, having the ability to limit how much can be woken up at a time by the kernel would be beneficial.
18. Re:Caution by Anonymous Coward · 2014-04-12 13:52 · Score: 0
  
  Then the hardware will control wake up events before the BIOS is done passing control to the OS.
19. Re:Caution by sjames · 2014-04-12 14:08 · Score: 1
  
  But it doesn't.
20. Re:Caution by camperdave · 2014-04-12 14:10 · Score: 1
  
  The power load of waking up 20 hard drives at the same time can be tremendous compared to the load when they're all spinning and purring.
  Spinning drives... how quaint!
  
  --
  When our name is on the back of your car, we're behind you all the way!
21. Re:Caution by Tough+Love · 2014-04-12 18:17 · Score: 1
  
  Also, consumer (and mass storage) grade 7200 rpm drives have significantly lower power surge than 15K drives.
  
  --
  When all you have is a hammer, every problem starts to look like a thumb.
22. Re:Caution by Nkwe · 2014-04-12 18:21 · Score: 1
  
  If your UPS dies, a suspended machine is screwed just the same.
  Not necessarily. Windows desktop machines can write out RAM to disk so that if power is lost during suspend, the machine can come back up to where it left off. It is basically a cross between suspend and hibernate. If power is maintained the machine comes up out of suspend almost instantly, if not it comes out of hibernate.
23. Re:Caution by Anonymous Coward · 2014-04-12 18:39 · Score: 1
  
  Something tells me that machines with a heavily RAID-ed disk subsystem are not exactly your usual candidates for frequent power cycles.
  In my case - which you may dismiss as anecdotal - they are. We live in the countryside, and so power outages are common, especially during the summer. So we have a pair of UPSs backing up the servers (about 1½ hours capacity with all disks spinning). The servers are three Synology boxes, all with RAID - two are the two-bay type, one is a four-bay type, and all drive bays are occupied with 3TB and 4TB drives, totalling 14TB in RAID (raw 28TB). Another pair of smaller UPSs keep the networking gear going, and allow the PCs to shut down; the laptop obviously keeps running as it has a couple of hours on battery.
  The power-up sequencing is very important. We don't want 4 drives per UPS powering up simultaneously on access.
  FYI, this is a home system. We're probably not alone in having 4 drives in RAID on a home server.
24. Re:Caution by Anonymous Coward · 2014-04-12 22:13 · Score: 0
  
  What year is it?
25. Re:Caution by eneville · 2014-04-12 22:34 · Score: 1
  
  When your cluster suddenly needs more power, you don't want to wait 10 minutes for POST, kernel booting, and copying quite a few GBytes from disk into RAM, when you can instead get up and running in a few seconds.
  You may know ahead of time when your systems are most at work, say 0800-1800, so WOL at 0730, for exmple.
  
  --
  Why UNIX?
26. Re:Caution by Anonymous Coward · 2014-04-12 22:52 · Score: 0
  
  If it's soft RAID then the MD driver will need to take care of it; ditto ZFS.
  
  I would assume that the Linux kernel developers have considered some of these edge cases, although I haven't checked. Maybe the answer is "Then you can't use this new suspend/resume scheme yet", in which case you're no worse off than you are now.
27. Re:Caution by drinkypoo · 2014-04-12 23:30 · Score: 1
  
  After all, I've gotten pretty used to putting a device "to sleep" and "waking it up" instantly.
  This is a UI issue. Mobile devices can simply turn off the display before they've actually entered sleep mode. How would you know? Your PC could do the same thing, but there would be fans running and lights flashing, so you'd be aware that it was trying to trick you.
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
28. Re:Caution by danomac · 2014-04-13 05:50 · Score: 1
  
  2014.4
29. Re:Caution by sjames · 2014-04-13 09:30 · Score: 1
  
  I doubt the MD driver or the ZFS pool even can take care of it. Unlike a hardware RAID, they do not (and can not without losing functionality) hide the underlying component devices (which may only be a partition and not a whole drive).
30. Re:Caution by Anonymous Coward · 2014-04-13 14:37 · Score: 0
  
  There's a reason why RAID controllers tend to wake up drives sequentially.
  And the RAID controllers will continue to do just that. All this change does is allow the kernel to continue resuming without having to wait for the device to report that it's ready. Any commands sent to the device in the meantime are queued.
  I hope someone tests these improvements with a few different brands of laptops. On one or more netbooks / laptops, the mouse touchpad was not restarted, leaving the GUI interface to be killed via tty2.
31. Re:Caution by sjames · 2014-04-14 07:55 · Score: 1
  
  A bit more slowly due to not running in parallel.
so how fast is fast..? by Anonymous Coward · 2014-04-12 09:18 · Score: 5, Interesting

On my SandyBridge-era Thinkpad Edge, with:
- one 7200rpm Hitachi drive from ~ 2011 and
- one Intel SSD 525 from ~ 2013,
Debian Testing/Sid with kernel 3.13-1-amd64 wakes up from RAM sleep in 1s or so, thus extremely covenient so I never shutdown/hibernate.. how much more improvement can you get?..
1. Re:so how fast is fast..? by Anonymous Coward · 2014-04-12 09:47 · Score: 0
  
  .. how much more improvement can you get?..
  According to TFA, 7~12x improvement. Reading Is Fun(damental). Try it some time, you'll be glad you did!
2. Re:so how fast is fast..? by elal1862 · 2014-04-12 10:00 · Score: 1
  
  My antique Latitude D600 needs a whopping 5 seconds to wake up, which is waaaay too long
  So yeah... How much more improvement do you need?
3. Re:so how fast is fast..? by Anonymous Coward · 2014-04-12 10:36 · Score: 0, Informative
  
  That's too slow... osx takes a second or so. And the newest windows is trying to copy osx resume speed. Perhaps now, linux is copying windows resume.
4. Re:so how fast is fast..? by pathological+liar · 2014-04-12 11:09 · Score: 1
  
  I have an x230 that I put a Corsair SSD in. It's running Ubuntu 13.10, so I guess it's running a 3.11.something kernel. On resume I can see the kernel block for 10+s (by the timestamps in dmesg) waiting for my SSD to get its act together. Screen is on, lockscreen is displayed ... but I can't enter a password because the entire system is waiting on the disk.
  It sounds like I will benefit from this.
5. Re:so how fast is fast..? by elal1862 · 2014-04-12 11:16 · Score: 3, Interesting
  
  Some perspective is needed here:
  We're talking about almost-a-decade-old hardware running a current linux version. Yet it's still fast enough to resume within 5 seconds, boot in 45 seconds, start libreoffice in 4 seconds, IOW: still quite usable
  My $200 says you can't run Mavericks on a (similar vintage!) PowerBook G4 with the same usability...
6. Re:so how fast is fast..? by Anonymous Coward · 2014-04-12 11:31 · Score: 0
  
  My Thinkpad w500{5400rpm,p9600,8G,6M-L2}; Using Fedora 20{kernel 3.13.9} goes from suspend-to resume in less then 3 seconds.
7. Re:so how fast is fast..? by Anonymous Coward · 2014-04-12 12:57 · Score: 0
  
  Hopefully you have some memory scrubbing going on If you work in a high altitude location.
8. Re:so how fast is fast..? by thegarbz · 2014-04-12 13:31 · Score: 2
  
  Think embedded. A device in complete sleep state can be powered for eons on a battery. Waking, doing whatever it needs to do and then going back to sleep waiting for the next interrupt is critical to battery life. In the micro-controller world the difference in battery life of 2 seconds of wake-up time can mean the difference between swapping out your batteries in a day or in a year. I have not very fond memories of counting how many cycles various assembly instructions will take to ensure the CPU on small micro controllers isn't awake for more than a few microseconds to meet some power requirements. The prospect of running a small linux machine the same way is quite interesting.
9. Re:so how fast is fast..? by camperdave · 2014-04-12 14:19 · Score: 1
  
  how much more improvement can you get?..
  Well, you could convince the sensors applet and the clock applet to wake up from suspend properly instead of randomly consuming all CPU cycles, preventing the gui from awakening.
  
  --
  When our name is on the back of your car, we're behind you all the way!
10. Re:so how fast is fast..? by ButchDeLoria · 2014-04-12 15:43 · Score: 1
  
  Well no shit, Mavericks is for x86 only.
11. Re:so how fast is fast..? by Trogre · 2014-04-12 17:58 · Score: 2
  
  A more useful metric, IMO, is how reliable the suspend/wakeup cycles are. For example, a particular Fedora 16 box I ran would suspend/resume with 100% reliability. That is, it would suspend every time you asked it to, and wake up every time you asked it to. Another Fedora 20 machine has 100% sleep and 0% wake. ie it goes to sleep and NEVER WAKES UP without a hard power cycle. Another machine had 100% sleep and about 75% wake, which is again utterly useless.
  
  --
  "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
12. Re:so how fast is fast..? by elal1862 · 2014-04-12 22:16 · Score: 2
  
  Hey, it's not my problem that Apple dropped PPC support with Snow Leopard *smirk*
13. Re:so how fast is fast..? by Anonymous Coward · 2014-04-12 23:08 · Score: 0
  
  Personally I've seen that Linux will spend most of it's time waking from sleep waiting to spin up my HDD.
  When that HDD isn't mounted, it's so quick I don't even think about it anymore thanks to the SSD.
14. Re:so how fast is fast..? by drinkypoo · 2014-04-12 23:33 · Score: 1
  
  My Ubuntu box has 100% reliable resume, but it only goes to sleep once or twice and then it refuses to go to sleep again. But I suspect that's just an Ubuntu problem :)
  
  --
  "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
15. Re:so how fast is fast..? by BestNicksRTaken · 2014-04-13 00:28 · Score: 1
  
  sounds more like you need a better disk or distro, my 5400rpm hdd resumes debian sid (3.13.7-1 but also 3.11 when it ran wheezy) in 1-2secs and i can type the password and get on with work instantly.
  
  --
  #include <sig.h>
16. Re:so how fast is fast..? by Samizdata · 2014-04-13 09:55 · Score: 2
  
  Stop reminding me, you insensitive clod!
  
  --
  It's not the years, honey, it's the mileage. - Colonel Henry Walton Jones, Jr., Ph.D.
not fast by lgalindo · 2014-04-12 09:19 · Score: 3, Insightful

will be happy if it does it right ...
1. Re:not fast by elal1862 · 2014-04-12 09:45 · Score: 1
  
  That largely depends on drivers, IOW: the willingness of hardware vendors to do things right.
2. Re:not fast by SuricouRaven · 2014-04-12 10:39 · Score: 3, Interesting
  
  And there lies the problem. Windows is very tolerant of badly-configured ACPI implimentations - it'll happily work even if half the configuration fields are wrong, as it simply ignores them and uses hard-coded suboptimal values. There's little incentive for OEMs to bother supporting any OS other than Windows, so typically once the firmware works for Windows it is considered good enough. All is well, until we stick linux on it - and linux then follows the ACPI specification correctly, and fails horribly.
3. Re:not fast by distilate · 2014-04-12 16:15 · Score: 1
  
  Or just bricks the machine
4. Re:not fast by YoopDaDum · 2014-04-12 19:42 · Score: 2
  
  The sloppiness in the PC ACPI world can also bite Windows too. You can find nice Asrock mini PCs based on laptop hardware. If you look at a Tom's hardware review of the Asrock VisionX 420, with a mobile core and mobile AMD GPU, you'll see that it consumes 28W at idle. This is crazy high for what's in effect a mobile laptop in small form factor box. One of the big reason is that the system ACPI says that PCIe ASPM (the low-power mode of PCIe) is not supported. Configuring laptop-mode on Linux and forcing ASPM results in idling at ~12.5W only, and a quieter box. Enabling ASPM in power saving mode alone saves ~8W, the rest is due to other suboptimal Windows defaults I guess.
  
  So IMHO the "let's do the minimum and ship" to save a buck approach of PC vendors hurts Windows and linux both. On the Windows side you'll usually get something considered good enough for its product class (here power was not considered as relevant for an HTPC it seems) but likely not optimal. On Linux you will get a mess by default because as you say vendors can't be bothered with it. But with some work you can actually get something quite good.
5. Re:not fast by Anonymous Coward · 2014-04-13 06:13 · Score: 0
  
  Disabling ASPM in a HTPC scenario might be a good idea to start alleviating video stuttering. They may have disabled C1 state as well for the same end.
It doesn't work at all. by Janek+Kozicki · 2014-04-12 09:29 · Score: 2

What's the point if suspend resume doesn't work at all?

Here's my SLEEP script, in which I am testing various kernels:

#!/bin/bash logger "========== touch forcefsck ===========" # if resume failed, then I want fsck (SSD disks, so it's just few seconds) touch /forcefsck /bin/sync sleep 1 logger "hibernating" # https://help.ubuntu.com/commun... # it says there to try hibernating using various different methods ### method: 1 kernel 3,13,0 - fail, (2/6 success rate) #/usr/sbin/hibernate ### method: 2 kernel 3,13,0 - fail, (3/6 success rate) #/usr/sbin/s2disk ### method: 3 kernel 3.13.0 - fail, (2/6 success rate) #echo platform > /sys/power/disk #echo disk > /sys/power/state ### method: 4 kernel 3.13.0 - (3/6 success rate) ### kernel 3.2.0 - 80% sukcesów 20% fail (over 80/100 success rate - currently in use) ### kernel 3.12-bpo - (0/1) success rate) echo shutdown > /sys/power/disk echo disk > /sys/power/state sleep 5 logger "restart network" ## something screws networking after resume /etc/init.d/networking restart sleep 2 ## also UPS connection is screwed (sometimes I need to disconnect and reconnect the USB cable) sleep 5 /etc/init.d/nut-client stop sleep 5 /etc/init.d/nut-server stop sleep 5 /etc/init.d/nut-server start sleep 5 /etc/init.d/nut-client start sleep 5 # don't mess with clock /etc/init.d/ntp restart logger "resume complete"
Besides, this is old news. Our new and better site beat slashdot: https://soylentnews.org/articl... . The only working kernel was 2.6.29 with tuxonice

--
# #\ @ ? Colonize Mars #
1. Re:It doesn't work at all. by jones_supa · 2014-04-12 09:38 · Score: 1
  
  I have had excellent results with suspend and hibernate on various laptops. I rant a lot about brokenness of OSS, but this is an area where Linux actually works really well today.
  What kind of problems are you having?
2. Re:It doesn't work at all. by Janek+Kozicki · 2014-04-12 09:49 · Score: 1
  
  It simply doesn't resume. HIbernation always works. You can see it on videos:
  
  http://www.pg.gda.pl/~jkozicki...
  The *.mov files are records from hibernation/suspend attempt. They have polish names, ignore that. You can see that it reboots again right at the end of resume, then boots into log-in screen
  
  I think it is related to my hardware: dual Xeon E5-2687Wv2, 64 GB of RAM, motherboard SUPERMICRO MBD-X9DRI, GPU nvidia GTX 780 (only debian approved nonfree drivers, no blobs from nvidia.com)
  
  --
  # #\ @ ? Colonize Mars #
3. Re:It doesn't work at all. by jones_supa · 2014-04-12 09:56 · Score: 2
  
  Sorry to hear about that. Probably a good idea to file a bug report at https://bugzilla.kernel.org/ (if you didn't already).
4. Re:It doesn't work at all. by SpankiMonki · 2014-04-12 10:02 · Score: 1
  
  What's the point if suspend resume doesn't work at all?
  
  Besides, this is old news. Our new and better site beat slashdot: https://soylentnews.org/articl...
  Well, if you'd bothered to read TFA, you would have known that there was a merge last night that specifically benefits the resume process. While it may or may not help you specifically, it is definitely NOT old news. BTW, your "new and better site" makes no mention of this at the time of this writing.
5. Re:It doesn't work at all. by Anonymous Coward · 2014-04-12 12:51 · Score: 0
  
  Our new and better site beat slashdot
  Your new site is so much better that you still read and post on Slashdot. From the looks of it, that site has next to zero users or discussions.
6. Re:It doesn't work at all. by Anonymous Coward · 2014-04-12 15:10 · Score: 0
  
  He didn't say that his site was more popular than Slashdot, he said that it was better.
  Well frankly, better is not all that hard to do, since Slashdot is not the tech-focused place that it used to be in the olden days. And the editors have never done any actual checking or editing here anyway, so the bar for competitors isn't set very high.
  A competitor that doesn't use Javascript at all would actually be very welcome.
7. Re:It doesn't work at all. by Barsteward · 2014-04-13 04:48 · Score: 1
  
  you'll get a headache if you keep nutting the client and the server
  
  --
  "The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
I'd rather have "easier to debug" by Cley+Faye · 2014-04-12 09:36 · Score: 2

My main issue with suspend with my laptop is that it never wake up. Now it can be faster at not waking up, wow.
I'd rather have a way to generate log and find the issue relatively easily.
Coupled with systemd and LinuxBios by Antique+Geekmeister · 2014-04-12 09:37 · Score: 2

There are quite a few things that slow booting systems. Systemd is _supposed_ to take a lot of the slow, sequential starup out of the actual system daemons: it will be a while before it's really working well for critical, production systems, but that can take minutes off of startup time in a large environment. Note, also, that much of its "startup advantage" is illusory. Daemons are told to start up, and systemd keeps them starting up, but they're not necessarily available for quite some time after startup. This especially applies to databases and bulky Java applications.
The kernel startup is another big factor. Scanning for, assessing, and activating drivers for all the potentially available hardware is a slow and painful process because the upstream specifications are poorly documented, and even violated by many vendors. Many of them are legacy drivers and could in theory be discarded in most production kernels, but doing so can be quite tricky and hard to test for enough strange configuration cases.
The third big software factor is the BIOS. "coreboot", formerly "LinuxBIOS", is blazingly fast compared to most proprietary BIOS's. It has made some inroads but is still not available for any commercial systems I can find. So no matter what is done in the other two factors, the BIOS is still a limiting factor of suspend and restore delays.
1. Re:Coupled with systemd and LinuxBios by whoever57 · 2014-04-12 09:51 · Score: 2
  
  Systemd is _supposed_ to take a lot of the slow, sequential starup out of the actual system daemons:
  So is OpenRC.
  
  --
  The real "Libtards" are the Libertarians!
2. Re:Coupled with systemd and LinuxBios by evilviper · 2014-04-12 10:35 · Score: 3, Informative
  
  The third big software factor is the BIOS. "coreboot", formerly "LinuxBIOS", is blazingly fast compared to most proprietary BIOS's. It has made some inroads but is still not available for any commercial systems I can find. So no matter what is done in the other two factors, the BIOS is still a limiting factor of suspend and restore delays.
  POST has to be performed by the BIOS when restoring from hibernation, but NOT suspend. So no, the BIOS is NOT a significant "limiting factor of suspend and [resume]" operations.
  
  --
  Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
3. Re:Coupled with systemd and LinuxBios by Antique+Geekmeister · 2014-04-12 10:42 · Score: 1
  
  That is a good point. It's still a limitation for restarts.
4. Re:Coupled with systemd and LinuxBios by nctritech · 2014-04-12 10:53 · Score: 1
  
  Modern UEFI BIOS implementations, even when booted to CSM mode, tend to spend an extremely short amount of time doing work pre-boot. The BIOS slowness was mostly due to heaps of unnecessary memory tests and diagnostics anyway. Once those stop happening, there's not much time spent getting ready for booting at all. Windows 7 on my Windows 8-shipped laptop with an SSD comes up to a ready-to-go desktop in less than 10 seconds from power on. The BIOS speed obstacle is largely solved on new machines.
5. Re:Coupled with systemd and LinuxBios by Antique+Geekmeister · 2014-04-12 11:36 · Score: 1
  
  I'm glad it's improved for your laptop: I agree that it's gotten better especially for laptops and SSD drives. I also agree that UEFI is helping. Unfortunately, I've tended to deal with servers, where it is _not_ a solved problem.
6. Re:Coupled with systemd and LinuxBios by arth1 · 2014-04-13 03:59 · Score: 1
  
  Modern UEFI BIOS implementations, even when booted to CSM mode, tend to spend an extremely short amount of time doing work pre-boot.
  I admin several UEFI booting servers, and they can take several minutes probing and verifying hadware and firmware before the boot commences.
  The switch from BIOS to UEFI has not helped one bit - rather the opposite, as the drive containing the UEFI boot binaries has to be enumerated and verified before the binaries can be loaded.
  Keep in mind that the kernel needs to not only work with PCs, but servers and embedded devices (where there's neither BIOS nor UEFI). Making things work well for 80% and to hell with the 20%, like some New Programmers advocate, is not viable for universal software like the LInux kernel.
Who cares? by Antonovich · 2014-04-12 09:48 · Score: 2

Tell me when they can make my laptop last for more than an hour without mains and I'll be happy. I need to upgrade but battery life under Linux is so woeful I can't justify spending the ridiculous prices they are asking these days. To get a similar laptop to the 3 yr old one I have (at least in terms of size, weight, memory and disk) I would have to spend the same amount today as back then. Where is Moore's law again? Even though I can't afford one, I was looking at the Dell XPS 13 but for a couple of hundred more (for similar specs) I could get a macbook air and have *double* the battery life with osx. I would even consider it if I could run Linux on it and get similar battery life to osx... But alas, I read it sucks just as much as on all other machines.
1. Re:Who cares? by Anonymous Coward · 2014-04-12 10:28 · Score: 0
  
  My 4-year old Thinkpad T410s gets over 2 hrs on an old batter with only 23 Whr of usable capacity. I have an even older Thinkpad with a replacement battery and it gets over 5 hrs on battery.
2. Re:Who cares? by Anonymous Coward · 2014-04-12 10:50 · Score: 0
  
  It can depend on the table. There have been some major problems with power features an the like in Linux because the tables will contain inaccurate information but Microsoft sometimes has their software ignore the table (and uses a hotfix with the correct info) if they know the information is bad. Linux doesn't always have the same ability.
3. Re:Who cares? by plasticsquirrel · 2014-04-12 11:33 · Score: 1
  
  You know, an idle kernel doesn't use much of your battery life. Bulky programs that crunch and munch on the CPU do. Saying, "Linux this" and "OS X that" doesn't make sense unless you know that it boils down to the kernel and kernel drivers. Have you run powertop to examine exactly which processes and drivers are responsible for draining your battery? Have you followed the recommendations given by powertop?
  
  Finally, have you considered the possibility that your battery might be crap, and that a higher capacity battery that works properly may be the solution, rather than abandoning your entire operating system, or abandoning the entire computer?
  
  --
  Systemd: the PulseAudio of init systems
4. Re:Who cares? by Anonymous Coward · 2014-04-12 12:15 · Score: 0
  
  Sterile, and wholly unpalatable to any and all school boards and academic department heads.
5. Re:Who cares? by Anonymous Coward · 2014-04-12 16:01 · Score: 0
  
  I know you said "laptop", but my netbook lasts 11+ sounds without mains.
  If you want a full powered machine, then you need power to power it.
  You can trade some of your power for power, and have more power.
6. Re:Who cares? by Hymer · 2014-04-12 20:47 · Score: 1
  
  Systemd: the PulseAudio of init systems
  Is this a good thing or a bad thing ?
7. Re:Who cares? by Antonovich · 2014-04-12 21:28 · Score: 1
  
  I tried powertop a few years ago but never had much success, though that was probably v1. I'll give it another try, thanks for the heads up.
  A friend dropped the laptop about a year ago (it was an "accident", though he was drunk...). It didn't seem to make a difference for the first 8-9 mths but it weakened the lid/screen joint and with 12 mths of opening/closing has started to degrade seriously. I could spend many hours to try and patch it up but I've never had much success with anything more complicated than building/rebuilding basic desktop machines (stuff with wood is a different story). It's also now 3 yrs old, and with the time spent to fix it and expense in getting a better battery, I was thinking it was better to simply upgrade. With Moore's law supposedly operating, I was expecting to get something considerably better for the same price, or considerably cheaper for the "same" specs. If I am going to fork out top dollar (or rather euros), then I at least want something with great battery life, hence my whinging...
  In terms of the OS, abandoning Linux (or even Ubuntu) is not something I'm seriously contemplating. I've worked professionally and personally with Windows and Linux pretty much equally over the last decade. At this stage in my life, my goal is to spend as little time on solving OS and OS-application level problems as possible. Been there, done that and it's not particularly inspiring any more. I have found I spend considerably less time maintaining Linux boxen (laptops, desktops or servers) for the same level of tidiness, security and performance. I want it to "just work", to know how it's "just working" and to spend the least amount of time achieving that. Ubuntu seemed to be the winner on this front for a long while (I've been on 12.04 for the last two years and it's what I've been installing everywhere for the last two years), though the shenanigans with upstart, mir, unity, etc. have made me wary. I'm a big kde fan when a UI is justified - and more importantly it's what I've been using for the last 10 years so I usually get shit done quicker for UI tweaks. I probably pay for that on several fronts - I regularly see various kde components munching cpu... If reasonable, I'll always try and do stuff on the CL or conf files but again, just because it's quicker and that means I know better what's going on.
  Mac would mean learning an entirely new (*nix-based but still) system, which would be hard to justify in terms of time. They are also usually top shelf, so it means paying top dollar. I could probably justify the initial time and expense if it meant that in the long run I'd achieve my goal of spending less time for a performant and secure system. Unfortunately, it is going to be a long time before I can disassociate Apple products with Steve Jobs. I worked with handicapped people for several years and Jobs' parking spot manoeuvre may well have taken Apple products off my shopping list for good. Governments don't seem to be punishing companies or people for "doing evil" so I'm reduced to doing it with my wallet... (and yes, I know he's dead... but Apple could have stopped/punished him for being a "bad ambassador" for the brand).
  Roaming within Europe is fast becoming free (included in the standard, 20-25€/mth unlimited everything subscriptions) for us here in France, so a Chromebook is becoming a viable option. I have a couple of personal dev servers (hurrah for 10€/mth physical servers!), and never really do proper dev on trains/planes/mountains anyway, so that part is fine - vim over ssh is virtually indistinguishable from local for my usage. The time needed for finding solutions for the 1-2 other desktop apps is now really the only remaining obstacle...
  But anyway, if I solved all the problems myself there would be nothing to bitch about on /.! :-).
8. Re:Who cares? by Anonymous Coward · 2014-04-13 00:54 · Score: 0
  
  My 2 year old HP Pavilion with an i5 and spinning disk does 2.5 hours on its original battery.
9. Re:Who cares? by WobbWobb · 2014-04-13 01:04 · Score: 1
  Long post, but very relevant.
  I recently got a Thinkpad X240 with the large batterypack (total of 96wh), + an extra batterypack of 23wh, have had it for 2 months now. It's running ubuntu 13.10 and i'm getting about 10-12hours of active usage from it daily. I also always bring the extra batterypack in case of emergency.
  Power consumption and batterylife with the large pack.
  
  2.8w (~34hours battery) - Lowest idle i've gotten it to (essentially nothing running, flight-mode activated so no radios or network, just logged in to gnome desktop, lowest brightness and leave it idle for 5minutes so it's doing nothing), but touch the touchpad or type anything and it drops by at least 4-6hours.
  4-4.5w (~21hours of battery) - Normal idle with wifi or 3g, screen at 46% and a few things running (a couple of terminals, ssh, webmail)
  5-8w (12-19hours of battery) - Normal usage when i don't really care, screen at 80%, wifi or 3g, lots of tabs, terminals, eclipse running in background..
  12-16w (6-8 hours of battery) - Abnormal usage (for me). I need to be compiling, watch FHD movies/flash-video or other crazy stuff to get it to these levels.
  Worst case scenario is 6hours of battery with the large pack, switch to the secondary battery (which i can do without shutting down due to the internal laptop-batter) and have 2 more.
  Best case, (4-4.5w) where it's usable for troubleshooting via ssh and stuff means I have 21hours, then switch to the extra pack and have 5 more.
  
  Best case scenario means I lower brightness to pretty low (which is still readable on ips screen, though not comfortable for extended periods of time) and don't browse the web (leaves mail, chat, ssh, serial console, wifi or 3g/4g), it reports a battery-runtime between 19 and 22hours, though I usually get around 16-20 hours. It heavily depends on what i'm doing.
  Bringing down cpu and gpu consumption is essential to make it last longer. Lots of stuff are insane resource-hogs. (Flash, javascript, other stupid stuff waking up every millisecond) so here's a few recommendations to get you started:
  
  Suspend Tab - Firefox suspends the tabs so they're effectively not running after a set period (i use 30seconds), so i can have my set of 50tabs open, barely affecting cpu usage (and in turn, battery)
  Flashblock - I hate flash, causes insane amounts of work for the cpu.
  TLP - Powersavings for laptops, i've got everything set to maximum power savings all the time.
  I really like this Lenovo!
10. Re:Who cares? by Antonovich · 2014-04-13 04:34 · Score: 1
  
  Hey, thanks heaps for that. The X240 looks pretty much exactly like what I am after, and Lenovo (here in France) seems to let you mix and match upgrades which is seriously cool. What upgrades did you make with your system to get those numbers? Did you up the RAM to 8GB? Do you have an SSD (on top of the cache disk)? What proc do you have? How much extra weight does the larger battery pack add? 12.5" will be noticeably smaller than my current 14" - how do you find the screen?
  Thanks!
11. Re:Who cares? by WobbWobb · 2014-04-13 10:19 · Score: 1
  Hi!
  I basically maxed everything relating to hardware, didn't select the I7 cpu though, I5-4300u has the virtualization support i sometimes need, and i prefer to have more battery instead of peak performance. This laptop could possibly use less energy under some workloads if selecting the I3 cpu, i'm not certain though.
  Hardware list:
  
  I5-4300u
  8GB ram
  FHD IPS Display (1920x1080)
  
  256GB SSD, Cache option disappears when you select ssd and/or 3g card
  touchpad with NFC and fingerprint reader (touchpad is a bit funky on the new lenovo's, it responds well and all after a few synaptic-configs in X, but it took me a couple of weeks to get used to not having ordinary buttons. And i haven't tried out NFC or fingerprint-reader, but they're a cheap addon)
  Backlit keyboard
  
  Large battery, 72wh + one small battery 23wh
  Intel wifi, 7260ac
  WWAN 3G/LTE card
  
  With the large battery pack it weighs in at 1630grams.
  i've written a basic guide to the tweaks i've done on a standard ubuntu install: Power saving stuff
Does it fix this issue? by tdelaney · 2014-04-12 10:16 · Score: 2

https://github.com/OpenELEC/Op...
Just determined in the last week to be due to async suspend/resume. From the various reports, oretty much all Intel hardware is affected.
1. Re:Does it fix this issue? by tdelaney · 2014-04-12 10:17 · Score: 1
  
  And of course, typo. "... pretty much".
I'll be happy... by Anonymous Coward · 2014-04-12 10:23 · Score: 0

... if it suspends and resumes without causing a kernel panic or crashes my video driver.
In other news... by mugurel · 2014-04-12 10:56 · Score: 5, Funny

Linus Torvalds is now said to suspend (but not resume) key linux developers up to 10 times faster.
Yeah yeah whatever by Anonymous Coward · 2014-04-12 11:40 · Score: 1

People don't have any real faith in Linux distros to properly suspend or resume in the first place, much less the speed at which they perform. That needs to be more in like with Windows or OS X before they can even begin to improve its speed.
1. Re:Yeah yeah whatever by Teun · 2014-04-12 15:04 · Score: 1
  
  I see you are mixing up the capabilities of Linux and the hardware.
  Linux can handle it fine but some hardware manufacturers don't disclose their methods.
  
  --
  "The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
2. Re:Yeah yeah whatever by Teun · 2014-04-13 04:22 · Score: 1
  
  Please explain your opinion.
  
  --
  "The likes of Facebook and WhatsApp are free to those whose privacy is of zero value."
3. Re:Yeah yeah whatever by danomac · 2014-04-13 06:28 · Score: 1
  
  You must be young. I still remember back when Gates was talking about making ACPI a black box (unfortunately it still is, I can see) so that no other vendors but Microsoft could use the power interface. Some companies (like Intel) are pretty good about these types of specifications. I still have an Intel desktop/workstation board on my main computer at home and it has no problems sleeping and waking up.
  I have had, unfortunately, problems with some other manufacturers doing the same thing - like Asus. (By the way, this isn't strictly linux, I couldn't get Windows 7 to suspend/resume on certain model Asus boards.)
  It most definitely has something to do with hardware vendors. If the auto manufacturers had it their way no DIY'ers would even be allowed to work on cars. Computers are no different.
parallelism by lkcl · 2014-04-12 11:58 · Score: 3, Interesting

.... um, it's 2014, the linux kernel is a critical part of the planet's internet infrastructure, is used in TVs, routers and phones all over the world, and you're *seriously* telling me that its internals aren't fully parallelised? i thought the linux kernel was supposed to be a leading example of modern operating system design and engineering.
1. Re:parallelism by epyT-R · 2014-04-12 13:31 · Score: 2
  
  You're assuming a lot there. How would you know if osx or windows NT kernels are 'fully parallelized'? Have you seen the source?
2. Re:parallelism by Anonymous Coward · 2014-04-12 13:48 · Score: 0
  
  OS X kernel is indeed open source. Darwin is indeed 'fully parallelized' :)
3. Re:parallelism by Anonymous Coward · 2014-04-12 16:36 · Score: 0, Troll
  
  i thought the linux kernel was supposed to be a leading example of modern operating system design and engineering.
  Nope, it isn't. That's what the Linux zealots have been telling us for the last 20 years, but the primary reason it's so widespread is because it's free. Period.
4. Re:parallelism by Anonymous Coward · 2014-04-12 17:44 · Score: 0
  
  What for? For what kind of applications a 'fully' parallel OS kernel would be advantageous? Would it be worth the overhead when you only have a few dozen cores?
  Keep in mind Linux is not an academical kernel. They can't rewrite the whole thing just because that'd make a hypothetical computer with infinite cores run a synthetic benchmark faster.
5. Re:parallelism by Anonymous Coward · 2014-04-12 19:00 · Score: 0
  
  Well if you find something better to use than the Linux kernel, then by all means use it!
6. Re:parallelism by Anonymous Coward · 2014-04-12 21:03 · Score: 0
  
  Defensive much?
  > Would it be worth the overhead when you only have a few dozen cores?
  If the option is between farm(1) or farm(12), yes.
  > Keep in mind Linux is not an academical kernel.
  Yo, stuff those acadamicals with their book learnin'.
7. Re:parallelism by Anonymous Coward · 2014-04-12 21:55 · Score: 0
  
  His message isn't "Why is Linux behind"
  It's "Why isn't Linux leading by example"
8. Re:parallelism by Anonymous Coward · 2014-04-12 22:19 · Score: 0
  
  Period.
  That is where I realized that you are retarded.
  If you want to end your sentence with three periods, just use ellipsis.
9. Re:parallelism by dbIII · 2014-04-13 02:19 · Score: 1
  
  He's missing a "y" in there somewhere and describing what happens when problems reading optical media on such systems bring the things to a screeching halt :)
10. Re:parallelism by lkcl · 2014-04-18 06:40 · Score: 1
  
  You're assuming a lot there. How would you know if osx or windows NT kernels are 'fully parallelized'? Have you seen the source?
  someone else answered about OSX. NT, based on the MACH kernel, has been fully re-entrant and multi-threaded for a looong time. also, given that the service control manager (which is a parallelised start/stop daemon service) is fully parallelised i'd be incredibly surprised if the same attention to detail wasn't also carried through on device-driver initialisation as well. although.... the only evidence against that is the "Debug Startup" mode, which initialises drivers in sequence (and shows you the sequence), but that could well be due to the request for "Debug Mode" rather than an underlying design. honest answer: don't know.
true, but for years it didn't matter, power stayed by raymorris · 2014-04-12 13:15 · Score: 1

That's an interesting point. As a Linux user for many years, I never cared about boot or resume time. That's only mattered recently, as handheld devices have become quite useful. My servers and desktop stay powered on for years at a time, so I never cared how many seconds a reboot takes. Obviously a tablet is different. With a tablet, I do care, I want it to start up and shutdown quickly.
WTF slashdot by Anonymous Coward · 2014-04-12 13:45 · Score: 2, Informative

I'm in beta and I click classic which is on top it gets me to classic, hit the comments link and brings me back to beta and this is in a fucking loop. Stupid assholes, a website should be about the content itself not the bullshit eye candy which is taking space anyway. FUCKING RETARDS!!!
1. Re:WTF slashdot by Anonymous Coward · 2014-04-12 20:30 · Score: 1
  
  Add "?nobeta=1" to your URL. Of course, it disappears when you click another link on the site, so you have to keep adding it all the time.
  Thank you Dice.
2. Re:WTF slashdot by Janek+Kozicki · 2014-04-12 21:04 · Score: 3, Informative
  
  Just go to a new and better site: http://soylentnews.org/
  
  --
  # #\ @ ? Colonize Mars #
3. Re:WTF slashdot by dbIII · 2014-04-13 02:21 · Score: 1
  
  Maybe if you get a username and log in you can be like me and never see beta.
4. Re:WTF slashdot by Anonymous Coward · 2014-04-13 06:33 · Score: 0
  
  Not to mention this same story was posted there back on March 23rd.
Beat Windows? by hcs_$reboot · 2014-04-12 17:54 · Score: 1

Sorry but the Suspend feature of Windows - called BSOD - is almost instantaneous.

--
Slashdot, fix the reply notifications... You won't get away with it...
1. Re:Beat Windows? by Anonymous Coward · 2014-04-15 07:37 · Score: 0
  
  Sorry but the Suspend feature of Windows - called BSOD - is almost instantaneous.
  Linux has a Suspend to Kernel Panic feature. It's not instantaneous, shows no logs or errnos (unlike Windows), and requires a hard restart. Windows is years ahead.
Sad this is big news for Linux users? by Anonymous Coward · 2014-04-12 22:44 · Score: 0

I have to start by saying I am not against Linux in the least. I commend the people who devote so much time on these projects. But I think the end results still lack any proof that Linux can keep up with the likes of a Windows or OS X proprietary development program. Having worked with Ubuntu, Mint, Fedora and others. I think they have been polished over time but have yet to have the shine that really makes them worthy. Power management has always been hit or miss, and mostly miss in my experience. I hope some improvement has finally come to Linux as many more are now trying Linux on laptops and mobile devices. On a desktop it was no big deal to simply disable power modes. I finally gave up on Linux as its very nature of development is hampered by its open source. A perfect example is how Google has managed to take Linux mainstream with Chrome OS given that it finds way to support it better with predefined hardware and a controlled apps store.
Sometimes structure is a good thing and it brings out a better product.
My Linux laptop boots faster than Win7 resumes by BestNicksRTaken · 2014-04-13 00:19 · Score: 1

My Clevo laptop is a Pentium-D and it boots Debian with encrypted root faster than Win7 can resume on my $$$ Core-i5 Lenovo.
So not sure we even need a faster suspend/resume, which is almost instant.

--
#include <sig.h>
Suspend/Resume speed is nice, but... by bjoswald · 2014-04-13 06:41 · Score: 1

How's the Haswell/Maxwell support coming along? ;-)
Caution by KingMotley · 2014-04-14 04:43 · Score: 1

How does your system handle powering up the softraid when you turn the system on now?