Conversation
hyeyoo

Hyeonggon Yoo

Edited 1 month ago
init_task is not the task_struct of the init process but of the swapper process.
It confuses me every time.
1
0
3
vbabka

Reply to @hyeyoo
@hyeyoo I wish it was called differently, I've recently had to explain it's not a process doing memory reclaim...
2
0
1
hyeyoo

Hyeonggon Yoo

Reply to @vbabka
@vbabka ....yeah it does not even perform 'swapping' despite its name
1
0
2
vbabka

Reply to @hyeyoo
@hyeyoo IIRC the name comes historically from swapping processes to be run on the CPU, which we'd call scheduling now, and swapping has a mm specific meaning
1
1
4
hyeyoo

Hyeonggon Yoo

Reply to @vbabka
Edited 1 month ago
@vbabka

Yeah and even worse, when mm people say 'swapping,' they usually mean 'paging'...
2
0
2
ljs

Reply to @hyeyoo
@hyeyoo @vbabka I was going to say "[writeback]" doesn't actually do the writeback, that's the emergency ('rescue') writeback kernel process but then I checked and that's been changed :0 so now it's [kworker/R-writeback] where R means rescue...
3
0
3
ljs

Reply to @ljs
@hyeyoo @vbabka (as an example of a 'confusing' thing)
1
0
1
ljs

Reply to @ljs
@hyeyoo @vbabka the rest of writeback is obviously super simple. *ahem*
0
0
2
hyeyoo

Hyeonggon Yoo

Reply to @ljs
@ljs @vbabka There should really be a committee dedicated to naming things….
1
0
2
ljs

Reply to @hyeyoo
@hyeyoo @vbabka they could look at madvise names to start with
1
0
2
vbabka

Reply to @ljs
@ljs @hyeyoo doesn't work, there was a whole committee proposing poison/remedy but got overriden by just two unfunny people :(
0
0
2
vbabka

Reply to @ljs
@ljs @hyeyoo maybe even the name swapper could be changed then, to e.g. idler?
2
0
2
oleksandr@natalenko.name

Oleksandr Natalenko, MSE verified

Reply to @vbabka

@vbabka @hyeyoo @ljs Can you think of any fallout for userspace if this gets renamed?

2
0
2
ljs

Reply to @oleksandr@natalenko.name
@oleksandr @vbabka @hyeyoo let's call it sasha then
0
0
2
vbabka

Reply to @oleksandr@natalenko.name
@oleksandr @hyeyoo @ljs unfortunately, yes, I wouldn't be surprised at all by monitoring tools breaking subtly if the idle process is renamed.
1
1
0
jann@infosec.exchange

Jann Horn

Reply to @vbabka

@vbabka @hyeyoo @ljs this reminds me of a "what is pid 0" blogpost by @danderson i read a while ago: https://blog.dave.tf/post/linux-pid0/
"It was called that because, now that we’re back at the beginning of Unix, one routine encompasses not only scheduling and idling, but also moving entire process memory images between the small core memory and secondary storage. Hard drives in this case[...]"

0
1
2
vbabka

Reply to @vbabka
@oleksandr @hyeyoo @ljs it would be basically as risky as changing an uapi header so that it breaks with a c89 compiler
1
2
1
ljs

Reply to @vbabka
@vbabka @hyeyoo @oleksandr you bastard
0
0
1
lkundrak@metalhead.club

HAMMER SMASHED FILESYSTEM 🇺🇦

Reply to @hyeyoo

@hyeyoo @vbabka wondering how much from this comes from unix and bsd. unix originally had a pid 0 swapper process that swapped whole processes -- their userspace memory and half of their kernel structure -- onto the swap devices. bsd retained this while they also added a separate capability to move individual pages to swap device. they also still retained the split of kernel process bookkeeping data into two structures -- the swappable and the nonswappable part.

1
0
1
ljs

Reply to @lkundrak@metalhead.club
@lkundrak @hyeyoo @vbabka funny, because nearly everybody swapped out bsd for linux also
1
1
2
lkundrak@metalhead.club

HAMMER SMASHED FILESYSTEM 🇺🇦

Reply to @ljs

@ljs @hyeyoo @vbabka not before they could cause irrepairable damage to unix with introduction of their networking api, symbolic links, ptys and similar abominations

0
0
2
osandov@fosstodon.org

Omar Sandoval

Reply to @vbabka

@vbabka @hyeyoo another terrible name I've had to explain multiple times is struct address_space

1
0
2
oleksandr@natalenko.name

Oleksandr Natalenko, MSE verified

Reply to @osandov@fosstodon.org

@osandov @vbabka @hyeyoo struct address_space is a terrible thing on its own even if we ignore its name for a moment

0
0
2
About social.kernel.org

Terms of service

  1. Please do not use this service in violation of the Linux Kernel Code of Conduct. Doing so will result in your account suspension with the referral of the matter to the CoC committee.

  2. "Repeating"/"boosting" someone else's status on this platform will be treated as endorsement and will fall under rule #1.

  3. You are encouraged to use this platform to promote your work on the Linux Kernel, but there is no restriction on permitted topics (with the exception of anything covered by #1 above).

  4. There is no requirement to post in English, but it should be considered the primary language of communication on this platform.

Privacy notice

The admins of this service have access to all posted statuses. They aren't looking, but if it's something they shouldn't know about, then you should not post it on this platform.

Please see the Linux Foundation Privacy Policy, which applies to this platform as well.

Getting your own account

If you would like an account on this instance, please check that the following applies to you:

  • You are listed in MAINTAINERS or CREDITS

  • OR: You have a kernel.org account or email address

  • OR: You have a long and established history of involvement with the Linux Kernel

If the above is true and you agree with the Terms of Service and Privacy Notice listed above, please use these instructions to request an account: