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The only real problem I have left with my XPS13 is with sleep/hibernate. I’d like it to work like macOS. It seems like that’s possible but it requires a swapfi
by Lio 7y ago
The only real problem I have left with my XPS13 is with sleep/hibernate.
I’d like it to work like macOS. It seems like that’s possible but it requires a swapfile to save state to. As far as I can tell that means enabling virtual memory which is a no no on SSD.
Just that and I wish Bluetooth remembered the on/off state it was left in after reboot.
- phoe-krk 7y ago> It seems like that’s possible but it requires a swapfile to save state to. Has macOS solved this issue differently? Do they save RAM state to some non-SSD non-volatile memory, or do they just not care and dump it to SSD anyway?
- eknkc 7y agoI believe they favour sleep mode where the ram is powered on and the state is kept alive on ram. Only when the sleep time goes too long or battery starts running low, they dump into SSD.
- Lio 7y agoIt's not the swapfile that's the issue it's having the swapfile also be used for virtual memory. If it was only used for suspend that would be fine because it would only be written to when you suspend the laptop, which in the grand scheme of things is pretty rare compared to writes caused by virtual memory swapping.
- chungus_khan 7y agoMac OS does the same in this regard though, but in my experience neither Mac OS or Linux are particularly aggressive at using swap anyway.
- seba_dos1 7y agoYup, macOS dynamically allocates swap files on disk when they're needed - that's why you may see 0 swap space in htop, which doesn't mean that it doesn't use swap.
- Lio 7y agoThat’s interesting. I wonder can Linux be persuaded to dynamically alter the swap space from 0 as part of the suspend script?
- chungus_khan 7y agoI think if you were to use a swapfile and set swappiness to zero it should behave like this.
- Lio 7y agoBrilliant! I think this is the going to be the answer. Have the swapfile but use swappiness to tell the kernel not to use it day to day. Thank you :D
- JustFinishedBSG 7y agoBoth s2idle and deep ( https://www.kernel.org/doc/Documentation/power/states.txt https://www.kernel.org/doc/Documentation/power/states.txt ) are what you want, and work. > Just that and I wish Bluetooth remembered the on/off state it was left in after reboot. That's just a Qualcomm problem. The BT is completely broken. Fixed in the latest kernel for me.
- Lio 7y agoI might be missing something but doesn't that still depend on swap space and having a swapfile and virtual memory set up? I'm fine with having a swapfile but I don't want it used for anything other than Suspend-to-disk. i.e. I don't want the SSD being hit with multiple writes caused by VM.
- JustFinishedBSG 7y agoNo they just enter lower power states and keep everything in RAM. I don't even have a swap and it works fine.
- Lio 7y agoSorry maybe I'm not explaining what I want to very well. On the Mac it will suspend to RAM but also dump to an image file at the same time. If the mac runs out of power it will later restore from the image once power is restored. That's possible on Linux using hybrid-sleep and suspend-then-hibernate but they require a swapfile. I haven't yet found a way to have a swapfile without allowing that swapfile to be used for virtual memory too. I worry that virtual RAM will eat my SSD.
- seba_dos1 7y agoHow often do you upgrade your drive? If you expect to change it sometime in next 5 years or so, I wouldn't worry about using swap on SSD at all.
- 7y ago