Linux 3.5 Released

diegocg writes "Linux 3.5 has been released. New features include support for metadata checksums in Ext4, userspace probes for performance profiling with systemtap/perf, a simple sandboxing mechanism that can filter syscalls, a new network queue management algorithm designed to fight bufferbloat, support for checkpointing and restoring TCP connections, support for TCP Early Retransmit (RFC 5827), support for android-style opportunistic suspend, btrfs I/O failure statistics, and SCSI over Firewire and USB. Here's the full changelog."

Comments

Ha ha he he

[Anonymous Coward]

It's funny. The Linux community put so much effort into trying to win the OS of the Desktop with so little success, but secretly won the battle of the OS on phones and tablets with hardly a fanboy.

Re:Ha ha he he

[Teresita]

Desktops were locked down under the Microsoft Tax, Linux never had a chance. Along comes another platform, and it was Microsoft left flapping in the wind.

Re:Ha ha he he

[Kjella]

Desktops were locked down under the Microsoft Tax, Linux never had a chance. Along comes another platform, and it was Microsoft left flapping in the wind.

As usual it was Apple coming in doing something people have done before, only much better. I remember Microsoft tablets, there's no doubt they were first - and unusable. It was just like a PC, except with a stylus instead of a keyboard which we all know is so efficient. Lately I've been a bit surprised though because Apple has taken real technological leadership in some areas, like the display on the iPad 3 and the retina MBP. Things where you can truly say that there hasn't been anything like that offered ever before. Makes me both want to love their gear and hate their walled in garden.

Re:Ha ha he he

[cpu6502]

Linux would still have failed if it had not been backed by google. Right now we'd all be discussing Apple iOS and Microsoft's Windows Phone, plus some ubuntu-derived distribution that only the engineers know how to install on their phone.

BUT along comes Google and they used their resources to make Android Linux a success, by selling direct to manufacturers. Now we just need Google to consider porting Android to AMD/Intel desktops.

Re:Ha ha he he

[El_Oscuro]

Also on ereaders. According to Wikipedia, almost all of the major brands run Linux.

Re:Ha ha he he

[jones_supa]

Yes, but Apple has the power to choose the components, which makes a difference to what we see on the marketplace.

Re:Ha ha he he

[Anonymous Coward]

iOS (which is BSD based) runs the majority of phones and tablets in use, while Android has the majority of the rest.

Citation? I smell an Apple fanboy.

http://fortunebrainstormtech.files.wordpress.com/2011/06/screen-shot-2011-06-21-at-6-28-47-am.png

Android continues to lead the smartphone market in the U.S., with a majority of smartphone owners (51.8%) using an Android OS handset.

http://blog.nielsen.com/nielsenwire/?p=32494

For tablets, Apple has a lead, but the numbers are quite low for total number of devices.
http://techcrunch.com/2012/01/26/android-reaches-39-tablet-os-market-share-standing-on-amazons-shoulders/

So overall, Android is king in marketshare. Not sure how you got "apple runs majority of phones and tablets". Maybe "only tablets, for now, because of headstart".

Re:Ha ha he he

[zixxt]

Linux has not won any kind of OS battle, much less on phones or tablets.

Linux is the Major OS of Servers, Super Computers, Television Sets, the God Particle

iOS (which is BSD based) runs the majority of phones and tablets in use, while Android has the majority of the rest.

Tablets yes, Phones not even close!

While it's true that Android phones tend to use a Linux kernel, that's not really a requirement. It's just convenient. Android could run on any kernel. BSD, Windows, Hurd, whatever.. And all Android apps would continue to function.

Android is the OS, not Linux. Linux is just the current kernel, and has absolutely no bearing on Android as a platform.

If Android can run on these other kernels as you say then why is not being done? Android outside of Linux is released under a permissive license, if any other kernels could do the Job Linux does I'm petty sure Google would of chose it, but alas no other kernel is up to snuff.

Re:Ha ha he he

[larry bagina]

There are three parts to retina graphics. 1. Is the hardware. Apple doesn't manufacture it, but they do select it. 2. Is the Operating system. The physical pixels double but the virtual pixels stay the same and the OS displays double-sized (@2x) images if available or pixel-doubles existing image (and they look like a bag of ass). 3. is the software -- it needs to provide double-sized (@2x) images.

Samsung or Dell can use a high-DPI screen but they're limited on OS modifications and convincing third party software to support it. Maybe android is better about scalable graphics, but Apple still has the advantage of synchronizing the hardware and software.

Re:Ha ha he he

[sjames]

Of course, IOS would have failed were it not backed by a big pile of corporate cash as well.

Re:Ha ha he he

[ZosX]

Android scales graphis just fine IMO. if you run something like an older game that was designed for a lower dpi device, it just scales it. Generally you have the option to allow it to run smaller in its native resolution as well. Many of the android games use vectors for sprites, so asides from backgrounds looking pixelated, the sprites generally look pretty decent. I dunno, I went from a phone with an 800x480 display to a tablet with a 1280x800 display. If you ask me, android, at least ICS and beyond, handles high resolutions very well. It will scale the UI to match the dpi of the phone. I don't think apple has any real advantage here.

Re:Ha ha he he

[Runaway1956]

You have one way of looking at it. Some of us have another view of the matter.

Anyone who does NOT want to rely on Mac or Microsoft, is going to choose - what, exactly? There are several Unix-likes out there, so Linux isn't a shoe-in. What is it about Linux, that made Google choose it over any other Unix-likes?

My money is on the pervasive GPL. The GPL fits Google's agenda better than any other licensing scheme, and that's pretty much the end of that story.

Re:Ha ha he he

[sonamchauhan]

The Linux desktops of old got transformed into Linux server, were gratefully used by Google for their server infrastructure.

Then, as mobile phone hardware began to resemble the desktops of yesteryear, Google went "hmmmm..."

And so it flows.

Re:Ha ha he he

[Teun]

Without Android the Nokia version of Linux might have taken off quite well.
There were and are plenty of consumers not endeared to the Apple ways and MS was never a contender.

Considering Nokia stopped official development of their Linux system around the time of their engagement with MS the N900 and N9 are even now still remarkably useful phones.

Re:Ha ha he he

[Zontar The Mindless]

The same people who scoff at Christians, Jews, and Muslims for believing in a God, are blind to the fact that they are zealots of another sort.

You, like lots of other Abrahamic religionists, are projecting. Lack of belief in the Abrahamic Deity != belief in some deity named "No Deity".

It's like the mediaeval assumption that, if you didn't worship God, you worshipped the Devil--and it's no more true today than it was then. Unfortunately, it's true that some people cannot accept the idea of not worshipping, so they adopt this false dichotomy instead, and try to back it up with circular reasoning.

It also implies that agnostics and atheists are Satanists, which is preposterous, since Satanism is simply changing the name but not the core tenet of the Abrahamic religions, and agnostics and (especially) atheists are not theists.

Re:Ha ha he he

[Anonymous Coward]

How the fuck did this get modded "insightful"? iPads and iPhones already have different aspect ratios (1.33 vs. 1.5).

Re:Ha ha he he

[gbjbaanb]

Linux always succeeded - only not anywhere you can see it.

Linux still runs 80%+ of the world's internet, Linux runs a vast majority of embedded devices. This is the reason Google got into it - it already was there when Google appeared and started to think "what web OS do we use for our HPC system" - it was pretty obvious to them to use the market leader in those arenas - Linux - and when they decided to go for an embedded phone device, they again chose the market leader in that area - Linux.

Linux made Google big, not the other way round.

Re:Ha ha he he

[DrXym]

Android support different resolutions just fine, but as a developer I can tell you what a gigantic pain in the ass this is. Layouts may look fine in one layout or resolution and terrible in another so you spend an inordinate amount of time fine tuning them to cope, or you multiply your pain by implementing specific layouts for specific device formats. When tablets turned up, the existing ldpi, mdpi, hdpi model proved inadequate so Android lets you write layouts that only fire when resolution is horizontally greater than some amount or other criteria but this only works in 3.x+. There are things you can do to keep the pain down (e.g. decompose layouts so you can reuse stuff) but it's still pain. Testing time also increases since you must test frequently in different devices and profiles to ensure it works.

You can get a flavour of the pain by reading what Google suggests to make apps run on the Nexus 7.

Apple has the advantage of owning the hardware and the software so there are a fix number of resolutions to support. I think if they start producing half-way house designs like larger iPhones or smaller iPads that they'll run into the same problem.

Re:Ha ha he he

[makomk]

The iPad has a different apect ratio from the iPhone, but that means that every existing application needed to have iPad support added explicitly in order to work well. Apple managed to get away with that since phone app UIs don't tend to scale too well on a 10-inch tablet anyway.

Every iPhone still has the same aspect ratio as the original iPhone and every iPad the same as the original iPad, though. Not only that but Apple had to delay increasing the resolution of their devices until they could get displays with double the pixel density, whereas Android manufacturers could use intermediate screen resolutions, and apparently driving all those pixels has been killing battery life and GPU performance.

android-style opportunistic suspend

[twistedcubic]

Now this looks interesting. Hopefully it works as described on the net (http://lwn.net/Articles/479841/). Automatic suspend would be wonderful.

Ext4 metadata checksums

[Peter H.S.]

Ext4 metadata checksums. I like that. Note that it isn't data CRC checksums, just metadata. Still, I like the way Ext4 keeps evolving and getting tuned. Btrfs sounds really great, but it may still be some time before it is stable enough for my data storage needs.

Re:Ext4 metadata checksums

[macemoneta]

I accidentally replied to the wrong thread. Repost:

Btrfs is stable enough for real data, if you run current releases (latest 3.4 or 3.5 kernel and btrfs-progs-19 current). I use it in both single drive systems and raid1 configurations with Fedora 17. Prior to converting the systems, I ran extensive failure testing (e.g., pulling power / data connection during active writes, system crashes, using a failing drive with media errors as part of a raid1, etc.) for about a month. I never lost a single byte of data in any test, confirmed by checksum scans on all data (against a backup) after each test cycle.

I actually trust btrfs now more than ext4 due to the ability to scrub the data and confirm integrity, which I do daily or weekly depending on the system.

Re:minor typo - "makes impossibles"

[macemoneta]

Btrfs is stable enough for real data, if you run current releases (latest 3.4 or 3.5 kernel and btrfs-progs-19 current). I use it in both single drive systems and raid1 configurations with Fedora 17. Prior to converting the systems, I ran extensive failure testing (e.g., pulling power / data connection during active writes, system crashes, using a failing drive with media errors as part of a raid1, etc.) for about a month. I never lost a single byte of data in any test, confirmed by checksum scans on all data (against a backup) after each test cycle.

I actually trust btrfs now more than ext4 due to the ability to scrub the data and confirm integrity, which I do daily or weekly depending on the system.

Re:minor typo - "makes impossibles"

[macemoneta]

With the current implementation and just the 'autodefrag' option added to default, there is no perceptable difference in performance compared to ext4 for any of our machines, with any application. Recent testing at Phoronix (with 3.4) has btrfs getting closer to ext4 (running without lvm2 and md raid); I'm curious to see how its numbers look in 3.5. However, because btrfs integrates the functionality of lvm2 and md raid in a much more usable manner, as well as providing much more functionality, a small performance tradeoff would be acceptable (to me).

Re:Desktops were also locked down under

[Anonymous Coward]

That is fundamentally what politics is about: getting people who want different things to act together in a useful way.

Re:minor typo - "makes impossibles"

[sjames]

So you're saying an orphaned inode ended up referenced by the wrong directory entry?

Re:checkpointing and restoring TCP connections

[Anonymous Coward]

It's a way of transferring TCP connections to another server (along with transferring the IP address). That way, you could do hardware maintenance on the physical machine without losing anything because you've migrated it seamlessly to another machine. Of course, you have to transfer and restore everything else over too (running processes, memory, etc).

Re:Linux-libre is the real deal

[dbIII]

GNU has nothing to do with the kernel at all. The LiGnuX and then later gnu/linux renaming suggestions were for entire systems that contained software written as part of gnu projects and not a totally different project such as the linux kernel. The gnu kernel is called hurd.
The point of the renaming was stated to be to "advertise" gnu on the back of a higher profile project, but personally I think it was just petty MIT staffroom politics that escaped out into the world. "But what have you done lately Mr Stallman" turned into pretended ownership of linux which certainly has the above poster and a pile of journalists fooled.

Re:checkpointing and restoring TCP connections

[sjames]

It's part of the larger project for process/system checkpointing in general.

That is, saving the entire state of a process to storage such that it can start up again where it left off and not know the difference.

What do you mean?

[billstewart]

Back when I was running X Windows versions 10.x and early 11s, there was no requirement that I use TWM. And while the Sun 2 came with SunView, the Sun 3 could run either SunView or X, and you could get Grasshopper Group's implementation of NeWS if you preferred, which drove your screen in Postscript. Among other things, that meant that if you wanted to change the font size to match the size of your monitor and your eyesight, you just did it, and What You Saw Was What You Wanted. None of this "need a third-party developer's hack to use the full resolution of the expensive Retina Display you just bought" nonsense. But even if you were running X, you weren't limited to Motif or OpenLook; you could run whatever window manager you liked with it.

As far as "Ubuntu [does] not [have an SDK]" goes, you can use the Gnome SDK or KDE or LXDE or several other fairly full-featured SDKs.

Re:Linux-libre is the real deal

[Gaygirlie]

Linux, the kernel developed and distributed by Linus Torvalds et al, contains software that is included without source code, with obfuscated or obscured source code and code under non-Free Software licenses. Linux-libre removes these parts.

http://www.fsfla.org/svnwiki/selibre/linux-libre/

So, you're saying it is a lot, lot less functional, possibly even to the point of uselessness. Hmm. Doesn't sound like my cup of tea.

Re:Apple's lack of support for Retina Displays

[Hawke]

Kinda off subject here, but ...

Your standard app was not written for silly-high DPR. You could show this on linux too: take your desktop, and crank the DPI to 300 or so, so that the X server thinks your screen is only 5" across. Now move far enough away from it that a 12 point font looks reasonable, and then look at how stupid apps look. Icons are microscopic (because they're defined in fixed pixel sizes). Layouts between menubars and borders look stupid (natural spacing was defined in fixed pixel sizes).

So Apple's approach here is to tell the application that the screen is 1440x900. Any primitives that can be scaled ("place the string 'pants' in font 'Helvitica', size 12pt, at X,Y". "Draw this 2kx2k pixmap in this 500px x 500px space") are then rendered to the screen's native resolution. Things that can't be scaled aren't ("draw this 96x96 pixmap here, in this 96x96 space"). Some apps then look horrible, some look great.

I personally would have rather they just let apps look like crap, and told people to fix their darn apps, but I can understand why they didn't.

Re:Desktops were also locked down under

[Burz]

It's got nothing to do with politics, people with different preferences just happen to build different things.

Politics are about group preferences and group identity. It's got a heck of a lot to do with politics: There's no rational reason to offer standardized frameworks under an SDK for mobile, but avoid doing so for desktops. One of the irrational reasons behind the disparity is that the hacker and sysadmin culture view PCs as immediate kin to web servers hardware and regard any standardization or vertical integration in the stack that caters primarily to "luser" needs as a threat to their freedom and efficiency.

The overall 'distro' mindset causes each and every initiative to become hamstrung with idiotic assumptions, such as:

- Each application should be broken down into between 2 - 20 different pieces and scattered around one's hard drive.

- Changes for most system components are handled in exactly the same way and with the same priorities as high-level applications, and apps get to make dependency demands on the inner workings of the system. There is no clear distinction between system and apps for anything being updated, added or removed.

- Anything other than the kernel = "application", and this type of system-hacker nomenclature must be observed by everyone or they will be ridiculed as 'n00b'. The result is a kind of blindness to real issues that arise around interactions between apps and system.

- System coders > App coders, so we will just get Miguel and some of the ol' gang to whip up some applications that will put Microsoft and Adobe to shame (i.e. we'll draw from the pool of Linux system enthusiasts to write user-facing apps instead of creating a feature-stable environment with an SDK to attract both newbies, and experienced app coders who are only newbie to 'our' system). But the reality is that the particular hacker culture and general feature-instability act as a corrosive acid against the kind of userbase and developer community that a personal computer needs.

- More than 10 people like to manage their PC software within a paradigm designed for servers.

- Fewer GUI admin tools are better b/c people will just want to hit the CLI anyway. Avoid the GUI when describing solutions, even WRT office/productivity if possible.

- A myriad different admin tools for basic network connectivity are OK because people want 'choice' (esp. when they call up tech support for their ISP or application and the technician can't figure out what specific steps to tell the user).

- Each year, desktop users must learn to recognize "Linux" by the current and past iterations of the 4 or 5 desktop environments that are officially supported by each distro.

- App developers like to design their apps for a disembodied desktop environment, instead of viewing the OS layers underneath as equally accessible tools. They also like testing their app in several other desktop environments to ensure that it "plays well" with them.

- App devs love having to test and package on multiple distros, and they look forward to having many camps of distro maintainers telling them about app "bugs" that mean you have to help them fix the same issue in their systems over and over again for a number of years. They also love having maintainers pepper and berate them over wacky compile switches, setting defaults, patches, etc. and they way they like to refer to app devs as "upstream" instead of "author", as if "Linux" coding automatically entailed some sort of demotion.

- If one is an ISV (distributing a proprietary app as 3rd party), devs love being regarded as an oddball instead of the norm, and love being reminded constantly that so many of the compatibility issues with (untargetted) distros they keep having to read about could be automatically resolved if, gosh, the author would only release their app as open source so they could be merged with repository nirvana.

- App devs love hearing they should leave behind all the PC stuff and

Re:Desktops were also locked down under

[Doctor_Jest]

It's funny, I've got a generic Dell PC I got for $300 from their outlet (Athlon etc etc.) Not a powerhouse, but not a shrinking violet either. I used my Mac Mini to download Debian Squeeze... and in 2 hours, with less interaction than a Windows install... I had a completely functional Linux desktop PC without doing anything in your list, except pick Debian. Back in college, I never got my et4000 card settings right for X on Slackware 0.99 (on floppies no less), but with screen and a familiarity with Amiga's CLI and DOS... I didn't miss it. (Plus that is the first time I got hooked on Nethack...)

Now, in the dim past just about everything was more difficult, to be sure... Getting games to run in DOS was also a magic trick. Then there was the myriad of other things that the CLI (which is where the computer originated) made easier for some, harder for others. Hell, Windows had a devil of a time keeping stable with the myriad of 3rd party drivers out there for Video and Sound cards alone.... Let's not forget NICs and so forth... And let's not diminish the fact that Windows used to be a graphical shell over DOS... for many years it was "hiding" DOS from the user...

Linux is a tool not everyone should use. There are idiots who shouldn't use a computer too. The fact that Linux has thrived in spite of Windows and Macintosh speaks more about the users and developers than it does about the drones who buy iPads and iPods because they're "hip". Those people don't use computers... they use appliances.

Here's a tip, though... if you hide everything from the user (a 'la original MacOS and returning to that I might add) it doesn't make them better at using a computer... it just makes them think all computers are magic. Which, in some people's case... I think should remain that way. :)

Re:BTRFS

[jarfil]

I've been using BTRFS in production since 3.3.1 with zero problems.

Before that, I did experience a partial fs meltdown on 3.2.x while stress testing a high number of snapshots with several million files/dirs and intense db activity. Then, the same test on 3.3.1 went flawlessly.

So I wouldn't recommend using BTRFS with anything below 3.3.1, but 3.4 or 3.5 should be fine.

Re:Desktops were also locked down under

[Doctor_Jest]

Sorry Linux guys Bill Gates and IBM beat you too it many decades ago and that is the bad news.

I wasn't aware there had to be winners and losers in the game. Computing thrived with diversity, heck if it wasn't for diversity, we'd all be using some pablum invented by Bill Gates in his dorm... Thank goodness he was chasing rather than innovating... I shudder to think of the alternate universe that would've made.

Linux didn't "lose"... it's free. Linux is doing fine and several companies make a good bit of coin off it. I see Microsoft's "victory" as nothing more than eating a bit more of the pie than the other guys. Apple's got a huge market cap and tons of cash in the bank, yet they aren't even 20% of the PCs sold worldwide... So in the realm of "winners and losers"... we have to be a bit more objective, or at the very least, define what "win" means. Market share? Revenue? Mind share? Brand Loyalty? Whatever you pick, you end up with a different "winner." :) But I applaud Microsoft and Apple for really bullying everyone else for so long.. it makes me feel good that giant corporations want to actively screw me over and sell me the tools to do it with. I'm talking about both Apple and Microsoft in this regard.

As long as there are people who like to do it themselves... there will be Linux. Computing trends come and go, but revolutions stick around...

Re:minor typo - "makes impossibles"

[macemoneta]

This was a bug that was corrected (it was a problem in cache flushing). All my testing occured after the bug was addressed, and pulling drive data cables while actively writing, as well as pulling drive power cables, was part of my testing. No data loss occurred in any test. The btrfsck and btrfs scrub/balance were able to correct all errors that resulted following the drive recovery.

Re:Apple's lack of support for Retina Displays

[shutdown -p now]

I personally would have rather they just let apps look like crap, and told people to fix their darn apps

Microsoft has had 20 years of track record with this approach, and the results are meh. Eventually Vista had to change the rules by requiring the apps to tell the system whether they are DPI-aware, and if they don't do that (e.g. all old apps), do bitmap scaling on them. Even so there are still quite a few apps written after Vista which do tell the system that they are DPI-aware, but then don't properly handle anything but the default 96 DPI.

Re:Apple's lack of support for Retina Displays

[exomondo]

But still, SRSLY? You'd think Apple could get font scaling correct, especially since they've been selling big desktop displays for years.

That still annoys me about OSX, you can't set the system font size.