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A warning about 5.12-rc1

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Re: A warning about 5.12-rc1

#71

Post by dale_glass »

londons_explore wrote: post #53

Why are swap files/partitions constant size? Most of the time, I don't need any swap at all, and any swap file/partition is wasted space. While hibernated, I need ~the amount of system ram as swap. While running some horrendous matlab script, I need about 1TB of swap. Yet linux won't dynamically allocate it like other files. I'm forced to constantly resize it manually to save space or be able to do more things.

It could get very messy. Think of it:

1. Something asks for memory from the kernel.

2. Kernel doesn't have enough free memory, goes to offload something old to swap.

3. Swap file is too small, needs to be extended. This calls the "extend file size" filesystem code.

4. Filesystem code tries to allocate memory for keeping track of filesystem data.

5. Goto 1.

As far as I understand, the "swap file on filesystem" system bypasses the filesystem. The kernel asks the filesystem to give it a bunch of blocks to work with and then ignores the filesystem code entirely. This is why some filesystems can't have swap files -- the FS has to support the right APIs, and has to be prepared for this kind of deal.

Re: A warning about 5.12-rc1

#72

Post by rob74 »

jlgaddis wrote: post #70
hjek wrote: post #51

Earlier quoted context omitted.

> So I'm not blaming the developers in question, Much kinder than past Linus writings. I loved it too. "Double ungood" works at least as good as the swearing.

I can recall a colleague, many years ago, sometimes using "doubleplusungood", often shortened -- in (typical lazy UNIX admin style -- to just ++ungood Later, another cow-orker tried using a slight variant ... ++!good ... although that one never really caught on -- apparently it didn't compile or something (maybe because we were using Red Hat's version "2.96" of gcc at the time?). -- (+10 Internet points if you get th…

Oops, sorry for giving it away in my comment ;)

Re: A warning about 5.12-rc1

#73

Post by jlgaddis »

rob74 wrote: post #68
hjek wrote: post #51

Earlier quoted context omitted.

> So I'm not blaming the developers in question, Much kinder than past Linus writings. I loved it too. "Double ungood" works at least as good as the swearing.

For anyone who didn't recognize it, that's a reference to Orwell's Newspeak ( https://en.wikipedia.org/wiki/Newspeak ). Which makes me wonder about two things: - is Linus hinting that he is censoring himself, and if he wasn't, what expression would he have used instead? - for what kind of incident does he reserve the attribute "double plus ungood"? Probably if such a bug would get into the production kernel?

> ... if he wasn't, what expression would he have used instead?

My first guess would be something that includes the word "fuck"... but, on second thought, this isn't Nvidia -- so perhaps not.

Re: A warning about 5.12-rc1

#74

Post by JediPig »

unpopular opinion here...

maybe if linus would fix kernel bugs ( i am looking at pulse audio right now ) even though it would break ABI, we would not have these long term issues.

Userland is a utter mess, because of fragmentation and the insanely deceptive "rule" of no breaking userland. Linux has 26 million lines of BLOAT, CORPORATE BLOAT. Eventually linux will be considered to bloated to continue.

As a hobbiest, I have no desire to work on the kernel, I may go work on a bsd kernel , cause they own both the kernel and userland. I am allowed to to change both, and make both better. It is why kqueue is vastly superior to epoll crap.

Sincerly,

A fat ass guy that has written more code than linus.

Re: A warning about 5.12-rc1

#75

Post by jlgaddis »

rob74 wrote: post #72
jlgaddis wrote: post #70

Earlier quoted context omitted.

I can recall a colleague, many years ago, sometimes using "doubleplusungood", often shortened -- in (typical lazy UNIX admin style -- to just ++ungood Later, another cow-orker tried using a slight variant ... ++!good ... although that one never really caught on -- apparently it didn't compile or something (maybe because we were using Red Hat's version "2.96" of gcc at the time?). -- (+10 Internet points if you get th…

Oops, sorry for giving it away in my comment ;)

It's okay, that's not the only one!

Re: A warning about 5.12-rc1

#76

Post by matthewmacleod »

rob74 wrote: post #68
hjek wrote: post #51

Earlier quoted context omitted.

> So I'm not blaming the developers in question, Much kinder than past Linus writings. I loved it too. "Double ungood" works at least as good as the swearing.

For anyone who didn't recognize it, that's a reference to Orwell's Newspeak ( https://en.wikipedia.org/wiki/Newspeak ). Which makes me wonder about two things: - is Linus hinting that he is censoring himself, and if he wasn't, what expression would he have used instead? - for what kind of incident does he reserve the attribute "double plus ungood"? Probably if such a bug would get into the production kernel?

You’re reading way too much into it - it’s just a colourful expression.

Anyway, “double ungood” would not be a valid Newspeak construction. The base is “good” and “ungood” is the negation; intensification would be “plusungood” and further intensification “doubleplusungood”.

Re: A warning about 5.12-rc1

#77

Post by fractalb »

hjek wrote: post #51
beachy wrote: post #2

Linus really does write beautifully. Love his style, concise, easily readable, frank, honest with nice human touches.

> So I'm not blaming the developers in question, Much kinder than past Linus writings. I loved it too. "Double ungood" works at least as good as the swearing.

I think that the word ‘Double ungood’ was generated by his auto correction program which automatically replaces all the swear words with some less offensive words

Re: A warning about 5.12-rc1

#78

Post by OskarS »

RegW wrote: post #35
kelnos wrote: post #26

Earlier quoted context omitted.

That email was many things, but concise is definitely not one of them.

... but remarkably good humoured! (Or are those teeth gritted?:-)

I thought so too! Linus was even like "don't blame the developers, this one was particularly nasty" and everything! Good to see nice and sensible Linus once in a while!

Re: A warning about 5.12-rc1

#79

Post by ddevault »

the_duke wrote: post #64

I used to assume that Linux had a huge test suite with hundreds of thousands of tests, given the crazy feature matrix that the kernel has to support. And that they would have started requiring tests for new features and bug fixes. Alas, that's not the case. There are a few external test suites like the Linux Test Project [1], but nothing that looks very extensive. The process seems to mostly rely on maintainers givin…

It is important to remember that this is the first release candidate of a series which is usually 7 or 8 entries strong. It's pretty far removed from shipping. This is a testing procedure, though not one which looks the way you're used to. In general, Linux ships pretty reliable releases once the rc process is completed.

Re: A warning about 5.12-rc1

#80

Post by yrro »

tremon wrote: post #65
ylyn wrote: post #11

Earlier quoted context omitted.

Swapfiles are quite common when you use FDE (say, LUKS) and you don't want your swap to be in plaintext on disk. (Although, you could just have an entire LUKS-encrypted swap volume instead of a swapfile...)

Even with full-disk encryption you have two options that I'd recommend over a swap file: - lvm on luks: inside the luks dm-crypt container, create multiple logical volumes: one for swap, one for the root filesystem - swap on dm-crypt: create a separate encrypted partition for swap Since the swap data needs no permanence, it's possible to generate a new encryption key every boot. Debian's crypttab supports this out of…

> Since the swap data needs no permanence

Unless you want to hibernate!

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