Cover photo
Verified name
Linus Torvalds
Works at Linux Foundation
Attended University of Helsinki
Lives in Portland, OR


Linus Torvalds

Shared publicly  - 
It's almost a year since I made a post here on G+ asking for peoples comments about gas compressibility calculations in scuba diving.

The resulting more accurate breathing gas compressibility calculations are one (very small) part of the new +Subsurface 4.6 release.

It has already successfully confused several people who learnt to do their SAC rate calculations using the ideal gas law.

Realistically, all the other changes listed in the announcement are much more important, but I had nothing to do with them, so they don't count.
The Subsurface developer team is happy to announce that release 4.6 of the Subsurface dive log program has been released.
You will find many improvements to the user experience (including a fix for spurious errors saving to cloud storage, improvements to the Facebook integration, many improvements to the dive planner and a really cool new heatmap for visualization of tissue loading during a dive). Subsurface can now download data directly from a number of new dive computers (thanks to Jef and the rest of the libdivecomputer developers) and also import several new data formats.
And of course there are a whole lot of bugfixes.
Look at the full announcement below, which also includes links to the binaries for Windows, Mac, and Linux.
User interface changes: Heatmap visualization of deco tissue loading: Re-designed Facebook access from Subsurface: Improved handling and visualisation of dive computer events in dive profile (grouping them into info, warning and alert -- best supported on Suunto EON Steel): Display surface interval ...
1 comment on original post
Linus Torvalds's profile photoG 尉遲恭's profile photoShawn Bakhtiar's profile photo
+Linus Torvalds Good to know; I was referring to the "taking over the diving world". As I understand it most of the other diving computers now use the Shearwater brain for their hardware. :P

Add a comment...

Linus Torvalds

Shared publicly  - 
So a winter storm warning is in effect here, with freezing rain and just generally miserable. Everybody is staying inside, because outside is basically trying to kill you by having cars sliding around like greased pumpkins.

But somebody always thinks there is a silver lining.

The mobile weather information from happily tells you:

Air quality: good
Ideal air quality for outdoor activities

No, Freezing weather with ambiguous snow/rain/ice falling from the sky, and the ground covered with ice is definitely not "Ideal air quality for outdoor activities".

The particulate counts don't really come into the picture at all, in fact.
John Smith's profile photoAri Lemmke's profile photoTomasz Konstanty “darkestkhan” Maluszycki's profile photoPaco R.'s profile photo
Paco R.
como es logico para una persona nacido en europa y mas un pais tan frio como Finlandia esta claro que le guste la nieve y el invierno!
 ·  Translate
Add a comment...

Linus Torvalds

Shared publicly  - 
Zai Puia's profile photoBenjamin Pirling's profile photoJoshua Mason's profile photo
I think I see a ripple with a fish butt in it.
Add a comment...

Linus Torvalds

Shared publicly  - 
Quick comments on Google WiFi..

I asked here some time ago about peoples favorite solution to good WiFi coverage when you have a rambling house. A single AP has never worked well for me, particularly with my office out away from the rest of the house above the garage (but the rest of the house is fairly spread out too).

For a while I've been running a Ubiquiti UniFi setup. It worked fairly well, and after working quite a bit on placement, I could cover the whole house with just two access points (but that really was after carefully placing them in the ceiling at just the right points).

But I've wanted to try the new mesh setups, and last week I finally decided to give Google WiFi a try. So here's a few comments about it, with the caveat that I really only have about a weeks worth of experience with it so far.

First off: setup really is as easy as they say it is. I've set up a lot of NAT routers and access points over the years, and Google Wifi simplifies things a lot by getting rid of all the unnecessary stuff. Particularly considering that it's a multi-AP setup, it really was that trivial. Just walk around with your phone while you're setting them up.

Of course, part of that simplicity comes from just having a lot of (sane) defaults and not a lot of complex management. With a traditional router setup, I would likely have tried to emulate my old network setup, including manually setting up DHCP addresses for the printers, because I've several times had issues with printers not really getting discovered properly otherwise.

With Google Wifi, it picked a subnet that wasn't what I used before, and while you can set DHCP assignment manually, it just wouldn't have been the same network anyway. So I didn't. But while it was different from what I've done before, I don't think it was necessarily wrong.

The other thing I liked is that the power supply seems to be a standard USB C power supply. I can't wait for special power supplies to just die, die, die.

That said, network routers are just about the only thing where one particular kind of special power delivery makes sense: PoE. Having two cables to plug into that thing is an annoyance after you've gotten used to PoE. That's particularly true if you want to place it in odd places (ie ceiling mounts or just other random hard-to-reach spots).

Yes, yes, you can argue that you only need the two cables for the master access point that is directly connected to your modem, and that you aren't going to have PoE coming from the modem anyway, and you'll have a nest of wires in that closet anyway.

The other APs only want power, and then USB C is much better than PoE.

That argument isn't incorrect, but it's not the full story either. The argument for Google WiFi is that the "pucks" are good-looking enough that you can just have them out. But that's complete BS if you then have to connect them right next to the modem, and have a rats nest of wires running around.

Which gets me back to my old UniFi setup: I had two AP's that were carefully placed in the ceiling, with just a single PoE wire going to each. Neither of them was in the closet where the cable modem and the NAT router and ethernet switch was, so the end result was that all the ugly stuff was hidden away, and the ones that had to be placed in the open really were very non-obtrusive.

Google Wifi doesn't really allow for that. Since you basically have to use the master AP as your NAT switch to get the easy setup and the full experience, that master AP has three wires going into it - the incoming internet, the power cable, and the outgoing ethernet to the wired part of the network.

End result: you get the three-device pack, but one of the devices is going to have to be hidden away, if only because of wiring. The "it's so good looking that you can keep it in the open" is BS when it comes to the master AP.

The others? Yes, you can place them freely, and they are fine. However, I don't know anybody who has their house wired for USB C. So you're going to have to place them near a power outlet, not in the ceiling, and it's not going to be as optimal as if you actually did a custom install.

So your pack of three has effectively shrunk to two AP's that you can place fairly around your house, and you won't be able to place them as optimally as you would a custom setup.

End result of all this: with three Google WiFi AP's I actually have worse coverage in the house than I had with just two optimally placed UniFi AP's.

This may sound like Google WiFi is a bad thing. But realistically, it really means that it's just different. My Ubiquiti setup actually took a long time to get to that optimal layout - I started with three UniFi AP's too, because optimal placement just isn't easy. There was tweaking going on, and a fair amount of running cable in attics and crawlspaces.

But with PoE and ceiling mounts, optimal placement is possible.

Google WiFi simply doesn't seem to aim for "optimal". It aims for "simple".

So which should you get? These days you can get the UniFi AP AC Lite for $80, or a 5-pack of them for not much more than the three-pack of the Google WiFi pucks. So they are actually cheaper than Google WiFi.

The UniFi setup doesn't include a NAT router (so you'd have to get that separately - but realistically that's going to be the existing wireless router that you just turn off wireless on), but it's PoE and designed to be pretty good-looking with a ceiling mount.

And the thing is, those UniFi access points absolutely have to be ceiling- or wall-mounted to look good, and they do need that ethernet cable. No wireless mesh, no trivial setup, no "buy it, connect it to your modem, and have a working good network in fifteen minutes or less". It's going to take a fair amount of effort to get a good UniFi network. You'll probably have to run cable in the walls, know how to crimp ethernet, and know how to set it up with a fairly complex controller on your main computer.

The Google WiFi points don't need any ethernet at all. They'll just work. No effort. No expertise needed.

So I'm going to continue testing Google WiFi. I have a fourth AP on order that I'll connect with ethernet in my office so that I'll have good coverage everywhere. That way I'll also test the "some of the mesh is wireless, some of it is wired". Let's see how it works. I think the convenience is probably worth it.
Cody Bishko's profile photodigi owl's profile photoTheodore Randolph's profile photoTichaona Gwati's profile photo
Always remember the Legends who did the project 
Add a comment...

Linus Torvalds

Shared publicly  - 
I took a welding class a couple of weeks ago. Not because I foresee ever needing to weld anything, but because learning new things is always interesting.

Yesterday was "add casters to the legs of the welding table we are building" day.

This is not my weld. But it is too funny not to share. The perpetrator of this weld shall remain anonymous to protect the guilty.
Jeff Stewart's profile photoPaul Frederick's profile photoPhilip Barnes-Roberts's profile photomark hubrich's profile photo
So just remember the correct parameters next time that's all... ./ -quality good -size .188 
Add a comment...

Linus Torvalds

Shared publicly  - 
So I've been a fairly happy "Project Fi" user for a while now, and a few weeks ago they started doing group plans too, so I thought I'd move a daughter or two over.

Setup was easy, but the level of just pure incompetence when actually mailing out the SIM-cards is scary.

I ordered a new SIM card on the 12th. On the 13th, they tell me it has shipped (good, good), using Fedex Smartpost. The tracking told me yesterday that the card should arrive today. Eh, ok, 8 days to get from California to Oregon, not great, but whatever - it's probably some "extra cheap saver" rate or whatever.

Today the tracking says "U.S. Postal Service will be delivering this shipment", and the scheduled delivery has moved to Wednesday.

Ten days? For a SIM-card?

Guys, if Amazon can ship just about anything in two days, you should be able to do better.

And quite frankly, if "Fedex Smartpost" just means ":we'll use USPS for the last mile delivery, and we'll waste a week before we even get to that point", why are you bothering with those jokers? Just plain USPS would have been 47¢ and gotten the job done in a third of the time.

Can somebody explain to me what the "Smart" part in "Fedex Smartpost" is supposed to mean? Because I'm not getting it. It makes both Fedex and Google look like they just don't care.

Before I had realized the level of incompetence here, I had ordered another SIM card last week for another daughter, because she was going to be back from college for Thanksgiving, so switching her over while she was home was "convenient".

Yeah, I'll give you one guess when that SIM card is supposed to arrive...
Scott West's profile photoHenri Seppanen's profile photoAnony Mule's profile photo
Because every time I turn on the smartphone that comes out
Add a comment...

Linus Torvalds

Shared publicly  - 
"Build your own deck" they said. "Weekend project - it will be fun", they said. "Think of all the money you'll save".

Yeah, almost three weeks later, and it's finally done. Well, except for the fascia boards. And I still haven't screwed down the three boards in front of the hot tub door that need to be removable. But mostly "done". In between kernel builds and all the rain.

And no, I didn't pour the concrete myself. There are limits to my stupidity. I had the piers done before the kernel summit, and started building when I got back.

I think Tove was worried it wouldn't be done before all the kids are back for Thanksgiving.
Dirk Herrendoerfer's profile photoPaul Frederick's profile photoNeil Franken's profile photoGregoryFrednotFred SpinoffGlavinovich's profile photo
are You really Linus Torvalds who wrote or created Linux ? are ...if you are Linus....the most famous person i bumped into on G+.
if not one of the executives of the big IT or software companies in Palo Alto or silicon valley
forgot his name already was by accident i found you
and coincidentally i just started reading Corel Linux for Dummies

+Eric Mintz....tour his G+ page...if you have the time

Add a comment...

Linus Torvalds

Shared publicly  - 
Google WiFi update.

So I talked about my Google WiFi experience a couple of weeks ago, here's some more updates from having a bit more experience with it.

Notably, I got my fourth unit, and what remains the real bright spot with Google WiFi is the easy setup. Adding the unit to the network was truly trivial, and when I then plugged it into ethernet at my office, things "Just Worked(tm)".

That's what I like to see.

That experience also just reinforced my opinion that these mesh systems really should be able to mesh both wirelessly and over ethernet - the wireless mesh is great for the trivial cases and for easy setup, and the wired mesh is what makes it so good to expand on the system and get to places that would otherwise be unreachable or cause unnecessary extra wireless hops.

So I continue to be a fan. I don't think I ever want to deal with a traditional wireless router again (but I'll make a separate post about using the Ubiquiti system in more challenging environments).

Small details that have cropped up in the meanwhile:

DHCP Reseverations:

As with every system before, I did end up having to make dhcp address reservations for the printers after all. Without doing that, discoverability is just too flaky. I'm sure the whole PnP experience works for some people without it, and maybe it's the particular printers I have, but giving the printers a static IP address just helps with all those situations where they otherwise don't seem to be discoverable.

This isn't specific to Google WiFi, and the App makes it fairly easy to do. But it would be more natural to do it when looking at the device in the network overview screen, rather than having to go into "Settings" and "Advanced networking".

What I'm left missing (and nobody else seems to do that either) is to add a new DNS entry for the device when I do this. The dhcp names are good as they go, and the DNS client on the router does the right thing with them, but having a printer named something like "HP874661" is not exactly a human-friendly name.

In fact, the IP address is easier to remember than the odd dhcp name. So I'd like to be able to add a "office-printer" DNS alias when I assign the IP to the device (or even without assigning an IP to it - some things are fine to leave as dynamic addresses, but you might still want to have a local name to reach them).

And on that note:

Like a number of other fancier routers, Google WiFi does traffic tracking, and let's you name your devices so that it's easier to see exactly which device does what (so you can have "Linus' Pixel Phone" instead of some ambiguous "Andoid-2" device). This isn't the DNS alias I'm asking for, but it makes it much easier to read the statistics. Good.

And what I found interesting was how much more useful this was when you just carry your phone around with an App, rather than having a web interface on your computer. I've used routers with per-device network statistics etc before, and I've named the major devices before, but Google WiFi made it really easy to just walk around and see "ok, that name refers to this piece of equipment" and give them all more useful human-legible names.

As a result, I ended up naming everything, including things like my Rachio sprinkler controller etc. Things that I've never bothered with before, because it was just not very convenient. Walking around with a phone I could just go to the kids and say "ok, show me your phone settings screen so that can tell which IP is your phone".

So the "configure everything on your phone with the App" clearly has some secondary convenience advantages. I'd have liked to be able to filter devices (by IP address and by which unit they were connected to), but even without that, the app just made some things much simpler.

However, I do note that not having a traditional web interface at all then makes the "what the hell was the printer called again" problem much worse. If I'm at the kids computer, configuring the printer setup, and I don't have my phone with me, I can't just look it up on the router config web page on the same device that I'm trying to configure the printer on.

So you win some, you lose some.

But that issue made me really want those DNS aliases, because it's so hard remembering what IP address you picked for the printer, or what the crazy dhcp name for the printer was. Let me just call it "office-printer" or something. 
Benjamin Staneck's profile photoDeva Annamalai's profile photoLinus Torvalds's profile photoAri Lemmke's profile photo
+Linus Torvalds​ ;-)
Add a comment...

Linus Torvalds

Shared publicly  - 
I take back everything I said about the nasty weather.

It got a bit colder and actually snowed. We got almost a foot overnight, and now outdoor activities are on. It's actually pleasant outside.

Of course, in our family, outdoor activities are apparently limited to not even bothering to clear the hot tub cover. 
G 尉遲恭's profile photoDustin Roeder's profile photorhy thornton's profile photoKlaus Hildner's profile photo
I wonder if the tub controller is running Linux. Because the towel post must be hanging on Windows ME!
Add a comment...

Linus Torvalds

Shared publicly  - 
Resharing the +Subsurface announcement, because it's been some time since the last larger release.
The Subsurface developer team is proud to announce our first beta version of Subsurface 4.6.
This version adds support for multiple new dive computers, the beginnings of multi-user support, and introduces new visualization of tissue loading on deco dives (the heat map, as seen in the picture below the dive profile). Plenty of bugs have been squashed along with improvements on dive planning and import/export functionality.
Head over to our website for the full announcement.
This version adds support for multiple new dive computers, the beginnings of multi-user support, and introduces new visualization of tissue loading on deco dives (the heat map, as seen in the picture below the dive profile). Plenty of bugs have been squashed along with improvements on dive ...
3 comments on original post
Xavier Acedo's profile photoTiffany Woods's profile photoMarko Shiva Pavlovic (in1t3r)'s profile photoPaco R.'s profile photo
Paco R.
seria interesante poder hacer una aplicacion de este tipo para los futuros relojes inteligente ... seguro seria hacer del reloj un dispositivo realmetne util por si misma. Algo asi como una mini-PC en su brazo.
It would be interesting to be able to make an application of this type for future intelligent clocks ... surely it would make the watch a real device useful by itself. Something like a mini-PC on his arm. ( Forgive my English, I'm not good at writing.)
 ·  Translate
Add a comment...

Linus Torvalds

Shared publicly  - 
As a software engineer, I'm convinced that electrical tape is a required structural element in any hardware hacking.

... along with random kitchen plastic ware.

This is the replacement power supply for the tiny milk fridge that goes with my coffee maker. So it's an essential piece of hardware to keep me sufficiently caffeinated to function well.

It turns out that the manufacturers power supply is unbelievable crap (I've gone through two of them), and it's hard to find 9V / 20W supplies.

"It's not stupid if it works"

Edit: by popular demand I fixed the typo, added some hot glue, and made holes in the box. Not adding a fan, because that's overkill.
Julian Haight's profile photoAlexey Shmonov's profile photoAditya Goturu's profile photoRabid Rotty's profile photo
As a former hardware tech, I fully endorse this message
Add a comment...

Linus Torvalds

Shared publicly  - 
I'm special. Hear me roar.
Marius PIEDALLU VAN WYK (EU Labs Account)'s profile photoSimon Quigley's profile photoAjoy Bharath's profile photoAniket Bhattacharyea's profile photo
Now I am not sure if I pronounced your name correctly in front of my students.
Add a comment...
Creator of Linux and git
  • University of Helsinki
Basic Information
SW Engineer
  • Linux Foundation
    SW Engineer, present
  • OSDL
  • Transmeta Corp
Map of the places this user has livedMap of the places this user has livedMap of the places this user has lived
Portland, OR
Helsinki, Finland - Bay Area, CA
I've been to Fish 'n fins twice now, once during off-season (June), and once during high season (November). Very professional. They clearly get very crowded during high season, but seem to successfully juggle having multiple boats out. Good diving, good people.
Public - 3 years ago
reviewed 3 years ago
1 review