LWN: Comments on "Linux on the Mac — state of the union"

Linux on the Mac — state of the union

jkt_ — Sat, 17 Dec 2016 12:24:46 +0000

> In my case I'm looking for a decent laptop purely for development, but almost all of them, except for a custom config of the 2015 base model macbook pro 15", have discrete GPUs.

I can recommend Thinkpad T460s -- it works just fine under recent Linux. I have colleagues that are happy with their Dell XPSs without a discrete GPU -- perhaps you're talking about Macs?

Linux on the Mac — state of the union

anselm — Tue, 13 Dec 2016 01:09:16 +0000

My Lenovo T460 seems to get at least 10–12 hours of use out of a single charge using stock Debian pre-Stretch, probably more with tweaking. I don't really see why I should pay extra for some “unique hardware features” and apparently a lot of drama just getting Linux installed. Given that the T460 has two batteries, one of which can easily be swapped out while the computer is running, it's probably simpler and cheaper (both in terms of real money and time saved) to buy another battery.

Linux on the Mac — state of the union

hobarrera — Mon, 12 Dec 2016 21:14:20 +0000

Did you even read the article? It talks in great details about unique hardware features that no other vendor offers (which are really useful for battery-saving).

Linux on the Mac — state of the union

aaahaaap — Mon, 12 Dec 2016 19:39:25 +0000

Awesome! Thanks a lot for your help/the info!

Linux on the Mac — state of the union

jem — Mon, 12 Dec 2016 15:07:48 +0000

This is a problem if you want to use the same disk on Windows, OS/X and Linux. There is an ugly hack to make the disk usable on all three systems: create the file system on the whole disk, then write a partition table with a partition that starts at sector 0. The UDF file system leaves some space unused at the start of the container it is in (disk or partition), which can be used for the MBR containing the partition table. This way the UDF file system appears to be both on the whole disk and in the first partition.

I found this solution on a blog a long time ago, and haven't tried it recently so I don't know if it still works. Even without the trick, the UDF disk should be portable between Linux and one of Windows (partitioned) and Mac (whole disk).

https://web.archive.org/web/20130313095817/http://sipa.ul...

Linux on the Mac — state of the union

cortana — Mon, 12 Dec 2016 12:51:47 +0000

I recall reading somewhere that Windows will only recongize a UDF filesystem if it's on the first partition on a USB disk, and Mac OS only recognizes it if the whole disk is itself formatted with UDF.

Linux on the Mac — state of the union

l1k — Mon, 12 Dec 2016 12:42:11 +0000

almost all of them, except for a custom config of the 2015 base model macbook pro 15", have discrete GPUs

The MacBookPro11,4 is the 2015 version without discrete GPU, the MacBookPro11,5 is the one with discrete GPU.

If I understand it correctly in cases where the integrated GPU controls the display outputs I should be able to fully disable the discrete GPU and not incur it's the power usage penalty.

Correct, but that's the case for both muxed and muxless systems. One thing to keep in mind though is that the external DP/HDMI ports can only be driven by the discrete GPU on 2011+ MacBook Pros.

Is there an easy way to figure out to which GPU the display outputs are connected? Maybe the info can be extracted from xrandr and the Xorg + kernel log?

This is e.g. logged in dmesg: "vgaarb: overriding boot device: PCI:0000:01:00.0" (that's the discrete GPU, the integrated is usually 0000:00:02.0). By default the firmware switches to the discrete GPU on boot, but this can be influenced with an EFI variable using tools like gpu-switch (linked in the article) or gfxCardStatus (on macOS). The MacBookPro5 (2008/09, dual Nvidia) is the exception to that rule, it defaults to the integrated GPU.

Linux on the Mac — state of the union

ismail — Mon, 12 Dec 2016 12:39:23 +0000

How do you format your drives? Whenever I try to format a usb disk with UDF, windows (8,10) complains that it's unformatted.

Linux on the Mac — state of the union

gravious — Mon, 12 Dec 2016 08:42:01 +0000

Good to know! Thanks!

Linux on the Mac — state of the union

aaahaaap — Sun, 11 Dec 2016 21:22:29 +0000

I think I understand, thanks for the info!

In my case I'm looking for a decent laptop purely for development, but almost all of them, except for a custom config of the 2015 base model macbook pro 15", have discrete GPUs.
If I understand it correctly in cases where the integrated GPU controls the display outputs I should be able to fully disable the discrete GPU and not incur it's the power usage penalty.

Is there an easy way to figure out to which GPU the display outputs are connected? Maybe the info can be extracted from xrandr and the Xorg + kernel log?

Linux on the Mac — state of the union

l1k — Sun, 11 Dec 2016 16:48:57 +0000

Yes, with "muxless" hybrid graphics, the integrated GPU is always on whereas "muxed" solutions need only one of the two GPUs to be on at any given moment. On top of that, muxless requires the frames to be copied over PCIe, so you have higher latency and need to spend additional CPU cycles for fencing to avoid tearing. With Thunderbolt eGPUs latency increases further.

Linux on the Mac — state of the union

raven667 — Sun, 11 Dec 2016 02:13:57 +0000

Without a mux then only one of the GPUs is be connected to the outputs and that GPU has to always be on, it can't be turned off even if it is the "inactive" one, IIUC.

Linux on the Mac — state of the union

aaahaaap — Sun, 11 Dec 2016 01:56:50 +0000

> Apple is the only remaining vendor to build a multiplexer into hybrid graphics laptops, which have both high-end and low-power GPUs. The multiplexer allows the panel to be switched between the GPUs and the unused GPU to be powered off. All other manufacturers use a "muxless" solution, whereby the discrete GPU is headless and copies rendered data over PCIe into the integrated GPU's framebuffer. "Muxed" solutions, such as the one used by Apple, offer superior power saving and latency, but are more difficult to implement.

Where does the XPS15 (9550) stand in this regard? Since it's discrete GPU can apparently be fully disabled, even when using HDMI (see https://bbs.archlinux.org/viewtopic.php?pid=1675168#p1675168), how could Apple's solution be more efficient?

Linux on the Mac — state of the union

johannbg — Sat, 10 Dec 2016 10:59:55 +0000

s/maybe/are/ some non-mainline in-kernel implementations like [1].

1. https://github.com/dorimanx/exfat-nofuse

Linux on the Mac — state of the union

jem — Sat, 10 Dec 2016 10:22:00 +0000

> In the last few years exFAT has been a good choice too.

Choice, yes. Good? No. There is no mainline kernel implementation of exFAT. There is a FUSE implementation, and maybe some non-mainline in-kernel implementations.

The reason exFAT is a second class citizen on Linux is that Microsoft asserts many patents on exFAT, and implementing support for it requires a license from Microsoft.

UDF also supports POSIX file system permissions.

Linux on the Mac — state of the union

aorth — Sat, 10 Dec 2016 09:14:37 +0000

In the last few years exFAT has been a good choice too.

Linux on the Mac — state of the union

mjg59 — Thu, 08 Dec 2016 04:04:47 +0000

The battery in the XPS 13 is apparently classified as user replaceable - they were happy to send me a replacement without sending a tech.

Linux on the Mac — state of the union

Matt_G — Thu, 08 Dec 2016 02:29:32 +0000

Thanks, I assumed something like that was the case. For hardware as new as this is it works remarkably well. Miles better then where things used to be.

Linux on the Mac — state of the union

ras — Thu, 08 Dec 2016 01:13:51 +0000

> Trackpad is probably biggest issue it feels very poor to use and often does not register clicks.

Make sure you are using libinput, as opposed to the Synaptics driver.

> The first time I closed the lid it failed to wake from suspend and I had to power cycle it.
> given Dell's support for Linux I would have expected it to work better out of the box (especially the SATA controller)
> The biggest issue was Fedora installer did not recognize the Laptop's built in SSD.

Intel, Intel, Intel. Intel hasn't published the specs for the "RAID" mode of their new chipsets. Their GPU drivers were abysmal, causing suspend / resume to fail (you probably could have ssh'ed in). I'm not sure "were" is the right word as they still are iffy in some corner cases - I'm hoping they will be solid in 4.9. Windows didn't have the "RAID" problem because Intel wrote a Windows driver, but if anything it has lagged behind the latest released Linux kernel when it comes to GPU support. (I have a theory the reason Apple didn't release a refresh for so long is Intel could not supply reliable GPU drivers / firemware.)

Be sure to keep your BIOS up to date - it helps with the GPU issues. Also, until this settles down ensure you poll Intel's site for GPU firmware: https://01.org/linuxgraphics/downloads

> I mostly operate it plugged in to a power outlet.

Then ensure you tell the BIOS to keep the battery at about 60%. This will do wonders for your battery longevity.

Linux on the Mac — state of the union

ras — Thu, 08 Dec 2016 00:53:19 +0000

I have a new XPS-15. There are lots of places Dell marketing says various bits aren't "user replaceable", and that includes the battery.

The first thing I did after getting the thing was to remove the back. I've pulled apart every Dell laptop I've owned for various reasons. This was *by far* the easiest to disassemble. You only have to remove screws on the back that are easy to find.

Once you do remove the back you are confronted with a sticker on the non-user replaceable battery. It says quote: "Please Disconnect and Remove Battery before Accessing The Rest Parts and Devices".

Linux on the Mac — state of the union

Matt_G — Thu, 08 Dec 2016 00:05:37 +0000

I live in Australia and purchased an XPS 13 last week (Dell had a 15% off offer on their website). More specifically I have the 2016 - 9360 model. The laptop came with Windows 10 preinstalled. I installed Fedora 25 on it. I have hit a few issues so far.

The biggest issue was Fedora installer did not recognize the Laptop's built in SSD. I did some searching on the web Arch Linux wiki is very useful and was able to fix this by entering the BIOS and changing the SATA controller to AHCI mode and disabling Secure boot. After I did this Windows would no longer boot. Not an issue for me but it maybe a problem if you wish to dual boot.

I see a few error messages flash up early on in the boot ( 'Ath10k failed to load firmware') but everything seems to work once the system is booted (including stable wifi connection).

The first time I closed the lid it failed to wake from suspend and I had to power cycle it. However it has successfully woken each time I have closed the lid subsequently. I have updated all of the packages on system since then however so it may have been as issue with the initial Fedora 25 installation which has subsequently been fixed.

Trackpad is probably biggest issue it feels very poor to use and often does not register clicks.

I can't comment on battery life as I never ran Windows on it for comparison and I mostly operate it plugged in to a power outlet.

Overall I'm mostly satisfied - however given Dell's support for Linux I would have expected it to work better out of the box (especially the SATA controller) and I am disappointing with Trackpad.

Linux on the Mac — state of the union

micka — Wed, 07 Dec 2016 21:45:37 +0000

I'm interested. Does this apply to the 9333 ?
Mine won't charge above 75% (well, provided plasma's charge indicator is correct).

Linux on the Mac — state of the union

danjared — Wed, 07 Dec 2016 21:29:12 +0000

The battery on the XPS 13 is user-replaceable. Here's the service manual section for doing that on the current model: http://www.dell.com/support/manuals/us/en/19/xps-13-9360-...

(Necessary notice: I work on Linux at Dell.)

Linux on the Mac — state of the union

clopez — Wed, 07 Dec 2016 17:04:11 +0000

Really? Whats different? Maybe the CPU architecture?

Linux on the Mac — state of the union

drag — Wed, 07 Dec 2016 16:23:08 +0000

They are all manufactured by the same Chinese/Taiwanese manufacturers.

By and large the only thing special about Apple is their weirdness when it comes to things like described in the article. That is, besides, their cases and such.

Why bother?

timrichardson — Wed, 07 Dec 2016 11:22:25 +0000

Three weeks with an 2011 Thinkpad w520 as an experiment to see what life is like after Macbook Pros has been a tremendous success. I have even Optimus working on three screens. This ancient machine can take 32 GB (since for $AUD 360 I got a quadcore). If I bought a 15" Macbook in 2017, it would max out at 16GB, the same as an old Macbook pro my son has ended up with. It still has a DVD drive, that's how long the macs have been stuck at 16GB. I don't think the 15" Macs have a compelling hardware argument any longer that would encourage me to deal with the problems of running Linux. What's the pay back? The pursuit of thinness has meant inferior keyboards, 2010-era RAM capacity, a terrible port selection and no expandability to go with a sealed battery and glossy screens. As for battery life, this ancient W520 on its original battery still gets me five to six hours. That's a 2nd gen i7. Skylake should knock the socks of it.

A good thing about Macs is they have high resale value. I'll sell mine, and it will pay for my experimental W520 and the P50 on the way. Apple doesn't help Linux, and there doesn't seem to be much reason any longer to even try.

Ubuntu by the way has been amazing. While I use linux a lot on servers, and increasingly in desktop VMs, I did not expect it to be such a capable replacement as a daily driver. I am completely convinced now.

Linux on the Mac — state of the union

voltagex — Tue, 06 Dec 2016 22:17:25 +0000

I've got an XPS 13 9350 - the patches to support NVMe aren't in yet, and it doesn't look like they will be any time soon [1]

1: http://marc.info/?l=linux-ide&m=147716441701110&w=2

Linux on the Mac — state of the union

rgmoore — Tue, 06 Dec 2016 20:38:15 +0000

It's certainly possible for Apple to lose some of their brand loyalty by putting out lame products or failing to keep their good ones updated. I've never liked their design approach. They're always looking for the next big thing and throwing away the current useful thing to make space, so you wind up having to buy new accessories or new dongles (which undermine the alleged simplicity of the design) with every new generation. Their ridiculous decision to go with a single USB type-C port as their only external connection on the new non-pro MacBook seems like the ultimate expression of that thinking.

HP Spectre x360

jani — Tue, 06 Dec 2016 18:39:57 +0000

The HDMI Alt Mode for USB Type C spec is brand new. I suspect it's DP Alt Mode with a DP-HDMI converter.

Linux on the Mac — state of the union

bronson — Mon, 05 Dec 2016 23:25:28 +0000

Same here. Their entire laptop line is getting weak against the competitors (possible exception for the niche 12" MacBook), and the Mini and Pro are downright embarrassing. About the only thing that still shines is the retina iMac.

I'm hoping Dell and Asus smell blood and move in for the kill.

Linux on the Mac — state of the union

mathstuf — Mon, 05 Dec 2016 22:34:44 +0000

In the office the latest round of hardware is getting sour reviews. No new Mini, a lackluster laptop, and a still overpriced and under powered cylinder. The only thing left is the one that lives in a monitor which can't be a machine that just lives under a desk all that easily.

Linux on the Mac — state of the union

rgmoore — Mon, 05 Dec 2016 19:44:30 +0000

Apple does put together some very nice hardware packages, not just in terms of raw specs but also in terms of design and quality of the components they use. They've cared about a lot of that stuff for longer than most of their competitors, so they have brand loyalty for their hardware even among some people who want to rip out their software and replace it with Linux.

Linux on the Mac — state of the union

bronson — Sun, 04 Dec 2016 18:29:43 +0000

I agree, it seems possible, especially since the hardware was made for gamers. But I don't think that PCIe supports bandwidth reservations does it? Display traffic is scary finicky, and more throughput doesn't cure latency problems.

If it can do seamless 60Hz 5K PCIe-passthrough while the CPU is pegged and some bursty disk/network I/O is going on, then I'll buy it. Especially with an external monitor or two plugged in.

Linux on the Mac — state of the union

excors — Sat, 03 Dec 2016 23:24:59 +0000

DisplayPort 1.3 apparently does around 26 Gbit/s, which is enough for 5K 60Hz. Modern NVIDIA GPUs support PCIe 3.0 x16, which is about 126 Gbit/s. That sounds like it should be plenty.

Linux on the Mac — state of the union

bronson — Sat, 03 Dec 2016 22:31:34 +0000

Good point. If PCIe has the bandwidth and latency, then I'm happy to consider it a virtual passthrough.

It's hard to picture it being sufficient for a 4K or 5K monitor... but busses these days are pretty amazing.

Linux on the Mac — state of the union

zlynx — Sat, 03 Dec 2016 21:37:10 +0000

It seems to me that Optimus / PRIME is already a pass-through solution. Instead of custom hardware it is sending the video buffer over PCIe to the GPU with the output on it. And it seems to me that we have this working pretty well these days.

Linux on the Mac — state of the union

karkhaz — Sat, 03 Dec 2016 00:27:37 +0000

In my experience Lenovo X2?? laptops have excellent Linux support, I'm very happy with my X230 (and yes, the docking station is lovely); and I know lots of folks with later models. I particularly like that the internal 3G modem works flawlessly, as these things often have terrible Free software support, but Sierra modems tend to play well with NetworkManager.

Linux on the Mac — state of the union

anselm — Sat, 03 Dec 2016 00:00:21 +0000

I have a Lenovo X250 from work and it's a sweet machine. The only thing I don't really like is the small display. I just took delivery of a T460 for myself (mostly because it has a bigger screen but uses the same docking station as the X250, which is convenient for working from home) and that is shaping up very nicely, too.

Linux on the Mac — state of the union

giraffedata — Fri, 02 Dec 2016 22:59:59 +0000

Then again, folks get religious about brand identity.

But if you're not running MacOS, you've given up the Apple brand.

So I still wonder what, besides the challenge, people want out of Linux on Mac hardware.

Linux on the Mac — state of the union

ibukanov — Fri, 02 Dec 2016 22:56:53 +0000

I use xps-13 with a generic usb-c - HDMI dongle (30usd before VAT in Norway). It works with a 4k monitor at 30fps. The only annoyance is that it takes like 6 seconds for the monitor to show a picture after connecting the cable or bringing back it from a sleep mode.