A turning point for GNU libc

http://lwn.net/SubscriberLink/488847/cb91a5cc3d179f3c/

by corbet • 14 years ago

192 86 14 years ago

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rcfox• 14 years ago

Are you sure you should be submitting "LWN subscriber-only content"?

It seems like they might not be too happy about that.

stfp• 14 years ago

I think OP is LWN's editor!

corbet• 14 years ago

Check my account name against the author of the article :)

I appreciate your concern. I do occasionally post a subscriber link in a place like HN or reddit with the idea of sharing some useful news and making people aware of what we do. So you shouldn't be worrying about me abusing the LWN subscriber link mechanism (which I implemented in the first place); instead, you should worry about my shameless and transparent marketing efforts :)

amackera• 14 years ago

Thanks for sharing, that was an informative article! Well done.

sounds• 14 years ago

Could you please comment on the appropriateness of other subscribers sharing a link like this?

Within certain bounds - glibc being a good example - the general interest in the article might justify its widespread use.

I would hazard a guess that for the majority of articles, LWN would prefer subscriber links be kept relatively "out of public circulation."

Thanks!

wickedchicken• 14 years ago

> you should worry about my shameless and transparent marketing efforts :)

Which totally just worked on me, by the way.

lambda• 14 years ago

As OP has pointed out, he's the LWN editor.

But besides that, LWN has a feature to allow sharing subscriber-only links for a reason. They want people to share those links and discuss them occasionally, as long as someone doesn't create an aggregator that posts all subscriber-only links. And all of the articles become public after a week, anyhow.

They are not trying to prevent people from discussing or reading articles; they are merely trying to encourage people to subscribe if they want to be able to see all of the subscriber-only content as soon as it's posted.

dannyobrien• 14 years ago

Can I just say that if you can subscribe, LWN is definitely worth every penny. It's everything a professional tech journal should be: detailed, topical, opinionated without being arbitrary, and consistently informative. They also do good deals on institutional subscriptions, which is useful if you want to talk to anybody else about what you've read :)

16s• 14 years ago

These links (not mine) may help explain a lot to those who may be unfamiliar with Ulrich: http://urchin.earth.li/~twic/Ulrich_Drepper_Is_A_.html

zoul• 14 years ago

Sweet Jesus, things like this really illustrate some dark corners of free software development:

http://sourceware.org/bugzilla/show_bug.cgi?id=4980

Where the high-publicity trolling in the later part of the discussion is even worse than Uli's initial stubborness.

justauser• 14 years ago

Is eglibc likely to merge into glibc?

I was under the impression that one of the reasons Debian moved from glibc to eglibc was friction with the project maintainer.

adestefan• 14 years ago

From what I've been reading, there will be efforts to remerge.

luriel3• 14 years ago

> The kernel may be the core of a Linux system, but neither users nor applications deal with the kernel directly.

The amount of complexity in a modern libc, glibc in particular, is mind-boggling.

One thing I love about Go is that it completely bypasses even libc, the Go runtime and stdlib use syscalls directly(well, except on Windows, for obvious reasons), in a way a Go program is "closer to the metal" than a C program.

drucken• 14 years ago

Unfortunately, Go with its mandatory GC is about as appropriate for systems programming as Java, regardless of how its marketed...

burgerbrain3• 14 years ago

For the more traditional definitions of "systems programming", yes. I would agree with that.

However I don't think anybody is really marketing Go for that niche.

Symmetry• 14 years ago

I don't know. Linus claims he can imagine writing an OS in Go (after they've spent a decade working the bugs out). Which is probably the most positive thing I've heard of him saying about writing kernels in other languages, and I'm inclined to trust his judgement over my own here.

EDIT: My memory was almost correct, he said that (in sharp contrast to C++) he can imagine letting Go into the kernel but not for a long time. http://www.realworldtech.com/beta/forums/index.cfm?action=de...

EDIT2: s/Linux/Linus/

tzs2• 14 years ago

What do you find incompatible between GC and systems programming?

4ad8• 14 years ago

I can, and in fact I do write an OS in Go, it's suitable enough for writing a kernel for me.

derleth• 14 years ago

> use syscalls directly(well, except on Windows, for obvious reasons)

Not obvious to me. Please elucidate.

koenigdavidmj• 14 years ago

Even the Windows API `system calls', like CreateProcess, are just wrappers around NT system calls. There are other wrappers too, like the Subsystem for UNIX Applications (which implements a POSIX API on top of the same NT calls).

wtracy• 14 years ago

Microsoft doesn't make the specs for the interface between the Windows kernel and the win32 libraries public.

xpaulbettsx• 14 years ago

You cannot call syscalls directly, as the syscall table is generated dynamically from the kernel source code on NT. The closest thing you can do is call the Nt* class of functions, which are often direct thunks to syscalls.

sciurus• 14 years ago

What makes this advantageous for Go? I imagine it takes a lot of knowledge to optimize a libc for different CPUs and kernels.

0xABADC0DA7• 14 years ago

It's not an advantage at all.

Google Go uses syscalls directly because its threads ("goroutines") were designed for a 32-bit architecture so their solution to not running out of virtual address space was to use small stacks that can grow. But that means it can't just call normal C function directly because there may not be enough stack, so they have to reinvent libc on every platform they port to. Meanwhile virtually every desktop is 64-bit and even ARMs will soon be 64-bit.

Why design a new language around 32-bit computers? Good question.

caf• 14 years ago

That means that a Go program is exactly as close to the metal as a C program, not closer (the C runtime and stdlib use syscalls directly, too - the C runtime is libc).

haberman2• 14 years ago

> in a way a Go program is "closer to the metal" than a C program.

It's amusing how often people try to one-up C with their favorite language, and how these attempts are almost never successful.

You can write C that doesn't use libc, that has no access to any system services, or indeed that runs under no operating system at all. For example, an operating system kernel itself. In no way is a Go program "closer to the metal" than a C program.

luriel3• 14 years ago

I was referring to a 'standard' program using the language's corresponding stdlib. And while not as useful this days C's "stdlib" is incredibly thick and complex. Go's stdlib is probably comparable to Plan 9's basic C libraries in complexity, but is portable and provides much more functionality.

Also note that Go can do all the things you mention, including writing a kernel.

Just to be clear, the real issue with C is not the language so much as the horrible libraries that have been built over decades of clumsily piling up complexity.

And the people who suggest glib is the answer to C's library needs are scary and depressing, glib just adds another layer of (very unportable!) crud on top of libc for no real gain other than keeping people from learning how to properly write C (data structures in particular).

4ad8• 14 years ago

You do realize that people write kernels in Go, right?

sneak• 14 years ago

I think the news here should be "lots of normal people are still surprised that the FOSS movement is littered with uncooperative sperglords everywhere you look".

The deeper and more complex a project, the higher my expectation for this type of behavior. I imagine a big venn diagram of "manages ultra-complex software in use by millions" and "social skills". Linus, of course, being the shining counterexample.

Seriously though, anyone familiar with FOSS projects should be entirely unsurprised by this. If you think I'm joking, go read some of Stallman's rants or peruse esr's "how to have sex" faq.

joshu• 14 years ago

sperglords is a term i plan to use in the future.

(i think you mean a disjoint venn diagram)

jbarham• 14 years ago

"Also significant is the fact that Ulrich left Red Hat in September, 2010; ...he is now VP, Technology Division at Goldman Sachs."

For me this is the punch line to the story. I wonder how he's liking wearing a shirt and tie to the office.

duaneb• 14 years ago

If I remember his temperament correctly, he'll love it on Wall Street. He'll have an entire division to yell at.

A turning point for GNU libc

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