5 ms·
Skylake's Linux power management is dreadful you shouldn't buy until it's fixed Why is this phrased as being an issue with Skylake, rather than an issue with L
by nkurz 11y ago
Skylake's Linux power management is dreadful you shouldn't buy until it's fixed
Why is this phrased as being an issue with Skylake, rather than an issue with Linux? That is, why not "Linux's power management on Skylake is dreadful and you shouldn't install it until it's fixed?"
Also, as someone who is running a custom compiled Linux 4.4 on Skylake, what's the best way to check what idle state is being used? Idle stats with 'powertop' shows the majority of idle time being spent in C8-SKL. Is this the same as the PC8 he's talking about?
- mjg59 11y agoIt's an issue with Skylake to the extent that Intel do their own hardware enablement for Linux and just haven't done everything they need to in this case. C8-SKL refers to the C state that an individual core is in - the package C states are listed further to the left in the "Package" column.
- nkurz 11y agoI think the package column is also showing C8, although I'm not familiar with the layout. Here's an example of what I currently see: Package | CPU 0 Powered On 0.0% | POLL 0.0% 0.0 ms C1E-SKL 1.3% | C1E-SKL 0.2% 7.1 ms | C3-SKL 0.0% | C3-SKL 0.0% 0.2 ms RC6pp 0.0% | C6-SKL 0.0% 0.0 ms C7s-SKL 0.0% | C7s-SKL 0.0% 0.0 ms C8-SKL 64.5% | C8-SKL 99.6% 9.5 ms | CPU 1 | POLL 0.0% 0.0 ms | C1E-SKL 0.0% 0.0 ms | | C3-SKL 0.0% 0.0 ms | C6-SKL 0.0% 0.6 ms | C7s-SKL 0.0% 0.0 ms | C8-SKL 100.0% 84.8 ms | ... What would I see if it were properly using C8?
- mjg59 11y agoHm. Which version of Powertop is this? Your output is corrupt - RC6pp is a GPU power state, the package states should all be "PC". The output I have looks like https://gist.github.com/mjg59/c753a7cb868fbbfa83e6060c4e4d0f9d https://gist.github.com/mjg59/c753a7cb868fbbfa83e6060c4e4d0f...
- mjg59 11y agoOh, are you on a desktop part? The issue is related to the mobile ones. I've updated the post to make that explicit.
- nkurz 11y agoYes, this is a desktop i7-6700. Sorry if that confused things. Yes, the addition to the top of the post is much clearer. Thanks!
- zxcvcxz 11y ago>"Linux's power management on Skylake is dreadful and you shouldn't install it until it's fixed?" Because Linux is sometimes the only option. No other OS has the same options as far as containerization.
- renaudg 11y agoWhat containerization options does Linux have running on bare metal, that a Linux VM running under OS X on a properly power-managed Macbook doesn't ?
- vetinari 11y agoProperly power-manager Macbook on OSX has its own share of hardware/driver-related problems (like the unreliable wifi), so let's not slide into irrelevant arguing.
- techdragon 11y agoOk so this is completely wrong. Both FreeBSD and the entire Family of OpenSolaris derivatives offer: - Superior "container" support to Linux (more secure, better tested, better designed, not a hacky bolted on thing like Cgroups.) - Their source code, they are Open Source Or did you actually just mean to say "Only Linux has Docker"?
- Sanddancer 11y agoFreeBSD even has docker, portname sysutils/docker-freebsd
- jessaustin 11y agoAre you saying that Skylake doesn't have these problems when running FreeBSD or OpenSolaris?
- colejohnson66 11y ago> - Their source code, they are Open Source So does Linux?
- 11y ago
- izacus 11y agoIt's phrased like that because it doesn't work on Linux and Intel refuses to document what has to be done in the kernel to make it work. As such it's hard to blame Linux kernel developers for not knowing how to magically poke the complex SoC into low power submission without Intel's cooperation.
- digi_owl 11y agoSadly that is usually what happens. Something or other do not work in Linux but work in Windows with OEM drivers installed? Blame Linux even though Windows is getting help from the OEM that Linux lacks...
- therein 11y agoTo be fair, Microsoft seems to be having problems putting the chip into deep sleep as well so clearly Intel is being too secretive this time. Maybe they are trying to cover something up about Skylake? I've heard from friends in OSG that they can't get the power consumption of the chip down to what Intel claims it should be in deep sleep.
- digi_owl 11y agoThanks for the heads up. Between that and the discussion elsewhere about designing with the intent of parts being "off" much of the time reminds me that Intel tried to replace TDP with another term that was supposed to take "typical" usage into account. Never mind that they recently abandonded their tick tock development strategy recently. Really starts to look like they have run into something troublesome...
- michaelmrose 11y agoGenerally someone is more invested in a particular OS than a particular CPU. I am far more likely to buy a different piece of hardware in order to have proper Linux support than to switch to an entirely different os. Whether its the hardware maker or Linux that is at fault is immaterial.
- gkop 11y agoBroadwell for example (Skylake's predecessor) runs Debian Jessie absolutely beautifully on my T450s laptop. Great battery life and integrated graphics performance.
- e12e 11y agoI'd rather it read: "Skylake's Linux power management is dreadful you should buy now and help fix it". But, as others have commented, this appears to be Intel not doing their job as hardware manufacturer. It's sad that we're still having these type of issues after years of cross-os growth on Intel/AMD architecture (Windows NT, Linux, OS X, *BSD etc).
- deleted 11y ago[deleted]
- michaelmrose 11y agoGenerally someone is more invested in a particular OS than a particular CPU. I am far more likely to buy a different piece of hardware in order to have proper Linux support than to switch to an entirely different os. Whether its the hardware maker or Linux that is at fault is immaterial.
- deleted 11y ago[deleted]
- edward 11y agoThe title of the post is actually "Skylake's power management under Linux is dreadful and you shouldn't buy one until it's fixed". I had to rewrite it to get it under 80 characters.