Lucid Sleep Support Is Being Worked On For The Upstream Linux Kernel

[phoronix]

Phoronix: Lucid Sleep Support Is Being Worked On For The Upstream Linux Kernel

Chrome OS supports "Lucid Sleep", which is a mode of allowing the system to carry out various tasks while the system is in a low-power mode or even suspended, and similar to Microsoft InstantGo. This feature, which allows for tasks like checking of new emails or instant messages while the system is suspended, is being worked on for (hopeful) eventual upstreaming into the mainline Linux kernel...

http://www.phoronix.com/scan.php?page=news_item&px=Linux-Kernel-Lucid-Sleep

[carewolf]

I can understand checking the battery level and switching to hibernation, but to check emails and instant messages you require the network layer up and some userland applications up and running. That is not sleep that is insomnia.

[lunarcloud]

I can understand checking the battery level and switching to hibernation

Why switch? Save to RAM and disk at the same time so that if there's battery, it restores from RAM and if not it restores from disk.

[HFriberg]

Why switch? Save to RAM and disk at the same time so that if there's battery, it restores from RAM and if not it restores from disk.

Maybe because disk writes on every sleep request is something you want to avoid in order to extend the lifetime of your SSD?

[Veerappan]

Maybe because disk writes on every sleep request is something you want to avoid in order to extend the lifetime of your SSD?

Agreed. I've disabled hybrid sleep on my macbook because I don't want 8GB of disk writes to happen every time I close the lid. It slows down the amount of time until the system gets to sleep, it's often unnecessary work (I may resume the thing in 5 minutes anyway), and it is unnecessary wear on the SSD.

[Zan Lynx]

Agreed. I've disabled hybrid sleep on my macbook because I don't want 8GB of disk writes to happen every time I close the lid. It slows down the amount of time until the system gets to sleep, it's often unnecessary work (I may resume the thing in 5 minutes anyway), and it is unnecessary wear on the SSD.

I did that on my Macbook Pro when I had one. I sort of regretted it later because I killed the battery once. Expensive at $129 to replace. That was a 2008 model with a replaceable battery. Who knows what has to be done now?

The problem is that if you disable hibernate the Macbook will never wake from sleep and hibernate itself. SO if you close the lid and forget about it for a week, the battery runs all the way down to 0%.

[Licaon]

IIRC Linus said something about catering to the desktop too, but too bad he did not say "FU guys/gals work on the desktop side" maybe (useful) things like this could of been worked on sooner/faster.

[old486whizz]

Why switch? Save to RAM and disk at the same time so that if there's battery, it restores from RAM and if not it restores from disk.

Why would you write RAM to disk >10 percent battery life left? (IMO this would be configurable).
Sounds like a waste of time and disk writes to me.

I am also a little puzzled with the email checking etc..
Unless you can tell the network chip to stay active and decoding network data (I'm thinking WiFi here) then you will need a length scan, reauth+connect sequence to occur at regular intervals - and that's just for local network auth, let's not forget about the userland apps + their auth (how up-to-date will IMs be?) And that is almost as wasteful as just having the machine in a dormant state with a tickless kernel.

[BradN]

So, wouldn't this just be treated as a low power CPU running the same kernel and code and everything? Or is it more of its own self contained system running separate software stacks for everything?

[curaga]

The problem is that if you disable hibernate the Macbook will never wake from sleep and hibernate itself. SO if you close the lid and forget about it for a week, the battery runs all the way down to 0%.

And why would that be an issue? All well-made batteries can stand that.