anyways @haughty kite mind coming to cork to buy me a new laptop
#Nyaux
silver yarrow
the cpu has no integrated graphics?
silver yarrow
then I doubt anything is wrong with the gpu
silver yarrow
is there a way to use that instead of dedicated
that would be the default
silver yarrow
default is hybrid mode
it depends on how you configure the OS
surreal path
it depends on how you configure the OS
bios*
haughty kite
yeah i guarantee its not the gpu
plush hearth
the keyboard just flashes twice
have you tried booting it no standard battery or cmos battery?
haughty kite
which laptop is it
surreal path
no
plush hearth
oh
because the issues sounds like it could be the bios
I've had the BIOS in my laptop randomly corrupt itself
surreal path
idk man im royally fucked
haughty kite
you may be able to repair it
plush hearth
does your laptop not have a way at all to restore the BIOS if it gets corrupted?
haughty kite
somehow
surreal path
you may be able to repair it
how
haughty kite
no
surreal path
plush hearth
you can still contact companies for support without having warranty
they won't be able to fix it for you for free
surreal path
im not waiting
4 weeks
im already so fucking done with acer
i just want a gaming laptop from a different manufactor
problem is
im poor
now i could do this thing where
i buy a laptop from very and pay it per month
but my dad is def gonna go and try and fix it
i dont think they will
since its a motherboard issue
and it will take weeks
plus i cant find a new preadtor pt14-51 motherboard online
so
🤷♂️
haughty kite
did you at least look for your symptoms in the mobo manual
surreal path
did you at least look for your symptoms in the mobo manual
theres no fucking mobo manual
💀
what u think acer is like HEY lets make a mobo manual for this fucking laptop
💀
bro its fucking acer
do u think they care?
plush hearth
4 weeks
I'm trying to tell you that one of there online technicians might be able to give you some other things to try without having to send it away
haughty kite
no i think you cant search the fucking web
user manual
seems like what would tell you there is an issue
haughty kite
on their website lol
third search result for "acer preadtor trition 14 schemaitcs"
surreal path
bro
silver yarrow
when u turn the thing on, does it actually turn on, just no output?
silver yarrow
and u cant enter bios
surreal path
and u cant enter bios
yea
haughty kite
yeah i think thats probably the best option lol
plush hearth
no, contact acer
surreal path
dealer*
plush hearth
"Contact your dealer or an authorized service center."
I think acer counts as an authorized service center or dealer
silver yarrow
I think you should expect it to take weeks unless u can fix it yourself
surreal path
I think you should expect it to take weeks unless u can fix it yourself
bro im not waiting weeks
im a spoiled teenager after all
haughty kite
you talk to acer support online
surreal path
they are closed
haughty kite
its new years eve give them a break
silver yarrow
you talk to acer support online
tbh you'll prolly just get someone whos gonna ask some basic questions and then refer you to a service center
surreal path
^
silver yarrow
worth a shot though
surreal path
can i have ur laptop wux
haughty kite
they might have diagnostic info
surreal path
do u know whats looking good rn
this rog strix g16 laptolp
anyone have a spare small bit of money
very small
just 2k
prwtty pwease
🥺
this laptop
omg
120hz oled
surreal path
bro
make me a desktop that isnt heavy and has a built in screen
oh wait
thats a laptop!
silver yarrow
laptops are so expensive compared to the shitty performance
my 2k laptop works about as well as a pc I could get for 400$
surreal path
oh my god
this is beautiful
i dont mind the laptop gpu downgrade
since i get 120hz oled
silver yarrow
my integrated gpu works as well as the discrete one
I put it in offload mode and have never used it since
tbf the discrete is fairly shitty
flat nymph
supple robin
🤢 wtf
worldly condor
buy an old used thinkpad
you can get good deals for like 250€
worldly condor
laptops are so expensive compared to the shitty performance
yeah, but what if you need it to be portable
I'm not talking about expensive gaming laptops
they're kinda cringe and clunky
and overheat
and don't have long battery lives
but like
just a cheap used ThinkPad
more then enough for most OSDev needs
unless you need to test on particular hardware and such
look at all those thinkpads
and then if you have a $2000 budget
you still have $1700 left for a pretty good gaming desktop
see?
thorn bramble
buy an old used thinkpad
you can get good deals for like 250€
u cant game on it tho lol
haughty kite
even a midrange macbook would be less than 2 grand lol
worldly condor
yup
haughty kite
u cant do anything on an old thinkpad
worldly condor
u cant game on it tho lol
who needs to game anyway?
thorn bramble
nyaux
haughty kite
who needs to game anyway?
factorio is a critical part of life
worldly condor
u cant do anything on an old thinkpad
I'm using an old thinkpad
worldly condor
factorio is a critical part of life
but you can surely run that on an old thinkpad
thorn bramble
u cant run the games nyaux plays on an old thinkpad
haughty kite
but you can surely run that on an old thinkpad
not well lmfao
worldly condor
then just buy a desktop then
haughty kite
sometimes people like moving
thorn bramble
he wants something portable
haughty kite
this is not a solution for everyone
that said i dont think i ever had a laptop that cost 2k
worldly condor
not well lmfao
I was able to run Minecraft 1.7.10 on a Netbook from 2007
thorn bramble
bro it's minecraft
haughty kite
I was able to run Minecraft 1.7.10 on a Netbook from 2007
1.7.10 is ancient
thorn bramble
and it's 1.7.10
edgy pilot
u cant run the games nyaux plays on an old thinkpad
no game, only osdev
worldly condor
ofc at like 20 FPS at 2 chunks render distance
haughty kite
and cpu is very hard on cpu
thorn bramble
ofc at like 20 FPS at 2 chunks render distance
🤦♂️
haughty kite
ofc at like 20 FPS at 2 chunks render distance
so it cant
worldly condor
it's playable
haughty kite
no its not
thorn bramble
20 fps isnt playable
worldly condor
I've played Minecraft at 20 FPS for years
haughty kite
also factorio isnt super playable at less than 60fps
thorn bramble
that doesnt qualify as playable
haughty kite
a lot of games arent either
haughty kite
also factorio isnt super playable at less than 60fps
(its fixed tickrate)
thorn bramble
just because you put up with it doesn't mean it's playable 
worldly condor
how do you think people who couldn't afford to spend $3000 on a PC in the mid-1990s played Duke Nukem 3D or Doom?
edgy pilot
also factorio isnt super playable at less than 60fps
game at 59 fps
literally unplayable
thorn bramble
just because you put up with it doesn't mean it's playable <:tf:7967551568880599...
different times + ^
worldly condor
nah
haughty kite
>game at 59 fps
>literally unplayable
59 is still fine
worldly condor
20 FPS is playable
thorn bramble
just because you put up with it doesn't mean it's playable <:tf:7967551568880599...
^
thorn bramble
- depends on the game
haughty kite
yeah that
molten grotto
yeah you don't want to play multiplayer games at 20fps at least
haughty kite
yeah this
haughty kite
you can play at 0.000001 fps
edgy pilot
then it's playable
you need to enjoy playing for it to be playable
edgy pilot
I enjoyed it
this guy probably used to hundreds of fps won't enjoy it
worldly condor
you can get used to it
thorn bramble
bro if i can watch a youtube video in a higher framerate than i can run minecraft at i will not enjoy minecraft more than a random youtube video
worldly condor
bro if i can watch a youtube video in a higher framerate than i can run minecraf...
?????
it's about interactivity
a YouTube video is not interactive
well
it can be
but it usually isn't
haughty kite
lol
worldly condor
especially a random one
edgy pilot
it's about interactivity
I think that's what he's saying
haughty kite
anyway this is very much not an experience i'd recommend
worldly condor
ok, but chess is still interactive, even if you can't do more than 20 moves a second
edgy pilot
ok, but chess is still interactive, even if you can't do more than 20 moves a se...
chess match rn
you and me
worldly condor
no
thorn bramble
so lower frame rates are not enjoyable anymore
molten grotto
20fps is like very visibly stuttery
thorn bramble
exactly
thorn bramble
that reduces the amount of fun you get out of the game
worldly condor
so lower frame rates are not enjoyable anymore
you get used to it again after a week
thorn bramble
why should i when i can just not
haughty kite
my experience with playing satisfactory is that you very much do not
worldly condor
why should i when i can just not
does Nyaux have $2000 to spend on a laptop?
haughty kite
but anyway this is not a viable option
thorn bramble
probably not but he probably also doesn't want to downgrade for reasons
edgy pilot
what would you choose:
30fps highest possible graphics
60fps medium
haughty kite
a 200$ thinkpad is not a viable option by any stretch of the definition
thorn bramble
60fps medium
molten grotto
^
haughty kite
yeah
for sure
also some games (factorio) are lockstep, you dont get half of the frames
you get the same frames, at half the speed
which is a lot worse
worldly condor
what would you choose:
30fps highest possible graphics
60fps medium
ofc 60 FPS medium
rigid fable
does Nyaux have $2000 to spend on a laptop?
why not pc
thorn bramble
...
edgy pilot
ofc 60 FPS medium
but graphics just look so good on maximum
rigid fable
because he needs a portable machine, I guess
😩
worldly condor
but graphics just look so good on maximum
what game are we talking about?
worldly condor
who cares what the graphics look like
molten grotto
lol
worldly condor
eh, just an excuse for people to buy a new PC every 5 years
edgy pilot
who cares what the graphics look like
when you're flying at mach 1.2 just 7 metres above the ocean it's incredible
rigid fable
eh, just an excuse for people to buy a new PC every 5 years
my computer has been with me for 12-15 years, I only change parts in it
edgy pilot
my computer has been with me for 12-15 years, I only change parts in it
ship of theseus
worldly condor
what are the specs?
rigid fable
what are the specs?
worldly condor
nice
finite summit
ah yes nyaux discussion
finite summit
finite summit
fastfetch is faster
finite summit
I think it's inside the actual neofetch script
rigid fable
I think it's inside the actual `neofetch` script
maybe
edgy pilot
finite summit
fedora is pretty based
edgy pilot
what does that mean
rigid fable
what does that mean
fedora is generally unstable
edgy pilot
and what does that mean?
rigid fable
and what does that mean?
idk just said
supple robin
i need to game
buy a pc
finite summit
zamn
edgy pilot
no osdev today cause laptop broken
osdev on termux
finite summit
he does
edgy pilot
common apple L
thorn bramble
you can but its not allowed on the app store
haughty kite
you can?
i thought you straight up could not
thats a new thing ig
oh its probably the browser stuff
kind root
you can?
if you're blessed by apple
thats why i think chrome uses apples js thing on ios?
thorn bramble
chrome is just safari with a facelift
surreal path
inb4 he has an iphone
i do
flat nymph
i go to my moms every weekend
Does she have good internet?
surreal path
Does she have good internet?
ehhh its decent
flat nymph
You can stream games from desktop
surreal path
i dont have a desktop
💀
and if ur talking about the family computer
i cant
my sister uses it
flat nymph
Get a laptop + desktop
surreal path
i dont have money
flat nymph
If you have 2000$
flat nymph
Then why were you looking up (obnoxious and) expensive gaming laptops?
flat nymph
Also idk if it's a good advice, but even iGPUs on new laptops are decent
Like don't buy gaming ones
flat nymph
Like what
surreal path
overwatch
tender gorge
i need ze gpu power
(x) doubt
surreal path
val
surreal path
not at 240hz
flat nymph
they run on potatos
surreal path
244hz
tender gorge
WHO THE FUCK NEEDS 240hz 😭
tender gorge
cringe.
surreal path
i have a monitor at 244hz
tawdry mirage
i have a 165hz monitor and i can definitely notice the difference
just on the desktop
flat nymph
I have 2 monitors, my old one is 60 and it's like looking at a slideshow compared to 144
tawdry mirage
yeah comparing my laptop's screen to the external monitor it's quite jarring
surreal path
its fine yk what
ill save up for a new desktop
i get 50 euro every week
50 x 4
200 euro
200 x 3
flat nymph
Also you're turning 18 soon (?)
You won't have to be visiting your mother if you don't want to
flat nymph
So like get a good laptop which isn't cringe and you could also use in college (if you go that route) instead
surreal path
So like get a good laptop which isn't cringe and you could also use in college (...
nah ill do an sfx build
and ill somehow make a bracket for the portable montior with my 3d printer
flat nymph
You can also probably buy a new motherboard for your laptop?
plush hearth
i will buy the parts month by month
you might be better off saving up to an amount where you can get a enough parts for a working system, then expand on it as you get more money
so you don't have mismatched components due to products disappearing for some reason
surreal path
you might be better off saving up to an amount where you can get a enough parts ...
i wont buy the gpu and cpu til last
tbf
desert haven
yeah the framework laptops are pricey :/
imo its worth it, but definitely not budget friendly, I agree with what frosty was saying earlier though
desert haven
you might be better off saving up to an amount where you can get a enough parts ...
.
broken depot
imo its worth it, but definitely not budget friendly, I agree with what frosty w...
Am hav framework laptop, can confirm
edgy pilot
@surreal path here you go. doesn't look too bad for just ascii
.:. ---:
*..#-. -# .-*
* :=.+*. :*--= ++ :*
:#. :*=:=+%- #. -+:.++: ----. %- +=
--== .:#. :*. .-*+-:..:=+---. :# -+ =#: +-
%# =-: #: :=*=-.. .::. .-+=. =* .%++.: .+
-% * .+==:..=- -:::: :*= +: -. .#= *
=+ :=. # =*. : -=*###**+ -*. :#.-- . +-
=+. -@=: -# =%@@@@@@@@@@+ .*. -*# -*:
:+--=+ .* *@@@@@@@@@@@@@@- .# -+--+=:
.. -+ *@@@@@@@@@@@@@@@@- *: ..
== *@@@@@@@@@@@@@@@@@@. +:
+: :@@@@@@@@@%@@@@@@@@@% +:
+: +@@@@@@+: .:+@@@@@@+ *.
-+ #@@@@+ :%@@@@@. -*
%+.@@@#. .#@@@@-:#.
.# .=- :+*- +-
=+-*: -: :+.
.:==--:. .:-=:..
::--:---:--:-..
Nyaux gofundme when?
he bricked it
surprisingly it wasnt Nyaux that bricked it
finite summit
allegedly
silver yarrow
LOL
thorn bramble
that wouldn’t even brick it lol
haughty kite
we have no idea if its a mobo issue tho it could be literally anything
including the display panel being fucked and that breaking post
idk could happen
thorn bramble
classic qemu
silver yarrow
U can probably crash the laptop too. but bricking it is a whole other feat
molten grotto
yeah its very hard to do from software
silver yarrow
wait he said his keyboard blinks twice
I wonder if thats like the equivalent of a mobo beep
he said nothing comes up on screen
could just be random shit or undocumented
I doubt the laptop has serial, that he has a serial cable, or a machine to which debug the serial output with
not to be a pessimist or anything lol
haughty kite
ask fucking support
haughty kite
I doubt the laptop has serial, that he has a serial cable, or a machine to which...
oh they defo have serial on the mobo
that wont work lol
broken depot
Because devices need drivers.
silver yarrow
oh they defo have serial on the mobo
Yeah, I suppose. More meant there wont be an port for it
haughty kite
yeah lol
broken depot
And this is USB
haughty kite
Yeah, I suppose. More meant there wont be an port for it
0 chance for that
it would just be some pins on the board
silver yarrow
yeah fair, didnt think of that
broken depot
You'd need to iterate USB, find devices, happen to notice this one and initialize your driver for it.
That is far harder than getting a bootloader like Limine to just give you a framebuffer for example.
Well then it needs to plug into something it is compatible with
And USB certainly won't be initialized before POST.
silver yarrow
And USB certainly won't be initialized before POST.
unless u have something relatively cursed going on
lol
most likely its meant that the thing receiving the output is plugged into the usb
and the thing ur debugging is connected over serial
thorn bramble
to what
wicked loom
legacy PCI lmao
thorn bramble
it's a laptop
wicked loom
even if it was a desktop the chances you had legacy PCI is slim
haughty kite
you also cant use random debugging cards
wicked loom
and no you cannot cut in half legacy PCI to fit in PCIe, that makes no sense
wicked loom
thats not how any of it works lol
it kinda is though
thorn bramble
no no that's totally how it works
wicked loom
it is
wicked loom
if you have a dumb PCI(e) card that uses port 0x80 i don't see the issue with it
yes correct
haughty kite
if you have a dumb PCI(e) card that uses port 0x80 i don't see the issue with it
how do you make sure the bios allocates port 0x80 to your device
haughty kite
also you still dont have any manuals
haughty kite
do you? lol
pci is packet switched afaik so yes i think you do
wicked loom
does PCI not have any mechanism to tell the BIOS to assign certain ranges of IO ports to a card that requests it?
sounds like something it should have
haughty kite
does PCI not have any mechanism to tell the BIOS to assign certain ranges of IO ...
i dont think so
thorn bramble
how do serial pci cards work then
how do you make sure bios allocates the right ports to the card
thorn bramble
i am not sure
wicked loom
what's the difference lmao
wicked loom
i think this mechanism exists
molten grotto
unless you find some old leaked version online
they are not even that old and nobody is buying them lol
thorn bramble
if there is my shit ass bootloader does not care
probably because pci devices can just yell at the bus and get what they want
wicked loom
ok you know what
@restive dock you prrrobably know
do PCI cards have a way to self assign IO ports at boot
is that PNP perhaps?
or something older/more basic
thorn bramble
as i said im pretty sure pci devices can yell at the bus and get what they want
thats how dma works, except iommu can control that
haughty kite
is that PNP perhaps?
oh maybe
thorn bramble
and there are some bits in the config space to maybe disable that but idk how that works
wicked loom
doesn't matter
haughty kite
same
wicked loom
PCI existed since forever
haughty kite
i seem to have the same 2019 pcie 5.0 version that coolbird has somehow
very convinient
molten grotto
its probably within the base spec if anything but it contains so much stuff its hard to search
credits 💀
thorn bramble
does the pci spec really have x86 specific stuff?
that sounds dumb
judging by the fact its used outside of x86
molten grotto
judging by the fact its used outside of x86
its just general io as far as I can tell, not x86 specific
haughty kite
okay so routing for IO port stuff looks like this
address, length, some other crap i dont care about
wicked loom
ok
haughty kite
okay so i didnt figure out if you can do that
but i did figure out that if your pci port is behind a bridge you are likely fucked
thorn bramble
isn't every port behind a bridge
or like at least 90% of the ports
that makes no sense
wicked loom
yeah i concur with the czapek
wicked loom
is there any PCI expert in here?
haughty kite
that said im like 99% sure its bios assignment
wicked loom
that meaning what?
thorn bramble
look at seabios then
if it is a bios thing the code must be there
seabios works on real machines
also since IO ports are described in AML there must be some static description of them, but its a matter of whether it is used during boot to configure it so the devices can use those IO ports or not
but i am pretty sure most AML isn't generated at runtime, so the IO ports being there are probably hardcoded
meaning it's merely a suggestion and the device can do anything it wants, just like with DMA
(except that DMA can be configured by an IOMMU)
haughty kite
my guess is that if the device starts with a nonempty bar then the bios uses that as a hint
thorn bramble
no need to guess
you can verify that by peeping the seabios code!
(i am too lazy to do that, and i have my opinion already)
(im also more than happy to be proven wrong)
haughty kite
you can verify that by peeping the seabios code!
i am trying
this is defo done in qemu though
or libpayload
thorn bramble
lol
haughty kite
or else im blind
flat nymph
Are you even doing osdev if you've never crashed qemu? 
thorn bramble
why would it be done in qemu
that means its not bioses responsibility? then whose? the cpus? the host bridge? that makes even less sense
flat nymph
it's a laptop
It probably has mPCIe for SSD or WiFi
haughty kite
why would it be done in qemu
idk man but it sure feels like qemu is the one doing it
okay time to read coreboot code
thorn bramble
sure qemu needs that tho
haughty kite
i give up
molten grotto
seabios allocates the port range, after looking at the code I am pretty sure it doesn't care about whats there to start with
haughty kite
fuck pci
thorn bramble
seabios allocates the port range, after looking at the code I am pretty sure it ...
how does it configure it tho?
as in, what does it do with the allocated port range
molten grotto
writes it to the bar
haughty kite
once you have the port you tell the device
i know how the bar allocation stuff works
on paper
wicked loom
?
haughty kite
you figure out where the device needs to have its stuff
thorn bramble
i forgot the BAR can hold system io addresses
haughty kite
and then you tell the device
thorn bramble
💀
thorn bramble
I KNOW!
haughty kite
shkwve even has code to do this stuff
broken depot
Are the BAR I/O addresses the ports that x86 uses for in and out insns?
wicked loom
so like, the device tells you where it wants its junk and then you just allocate it there?
haughty kite
so like, the device tells you where it wants its junk and then you just allocate...
no i dont think so
so what i thought it works like is this:
- bios looks at all the io bars and their sizes
- bios picks a base for each io bar
- bios writes that base into the io bars
- profit
thorn bramble
it doesn't
haughty kite
so what i thought it works like is this:
1. bios looks at all the io bars and th...
but that is missing the step where qemu does stuff
haughty kite
I wonder how that works for things like RISC-V.
its memory mapped
thorn bramble
they only do mmio BARs
haughty kite
you get a DT range
with the offset
you find a device with the pci-host-ecam-generic compatible
then get the ranges prop
broken depot
Oh well in that case I already support that :P
haughty kite
then do a bunch of parsing and one of the things in there is the address that an io range maps to
theres a type field in there
broken depot
I know
haughty kite
type 1 is iobar
broken depot
Because I implemented all of this literally a couple days ago.
haughty kite
lmfao
pub fn pci_ranges(self) -> impl Iterator<Item = PCIRange> {
self.u32_items().array_chunks::<{ 3 + 2 + 2 }>().filter_map(
|[flags, bus0, bus1, cpu0, cpu1, size0, size1]| {
let size = (size0 as usize) << 32 | (size1 as usize);
let cpu = (cpu0 as usize) << 32 | (cpu1 as usize);
let bus = (bus0 as usize) << 32 | (bus1 as usize);
let spacecode = (flags >> 24) & 3;
let range_type = match spacecode {
1 => PCIRangeType::IO,
2 => PCIRangeType::Bar32,
3 => PCIRangeType::Bar64,
_ => return None,
};
Some(PCIRange {
typ: range_type,
size,
cpu_addr: cpu,
bus_addr: bus,
})
},
)
}
this is what you can generously call my pci ranges field parsing logic
wicked loom
you said "this is where qemu" something
broken depot
At some point
thorn bramble
i still think that
the device can read/write any io address
and that is only so the IO address can potentially be remapped
in case of conflict with other devices
broken depot
IIRC those PCI POST code cards work by snooping the bus for any writes to port 0x80. That's simple enough it can probably be made on a CLPD or tiny FPGA.
wicked loom
the device can read/write any io address
ah, that would make a lot more sense
haughty kite
IIRC those PCI POST code cards work by snooping the bus for any writes to port 0...
okay but that doesnt make sense
thorn bramble
i have no idea, take what i say with a grain of salt
haughty kite
think about it: the pci bus is really fucking fast
broken depot
PCI, not PCIe
thorn bramble
IIRC those PCI POST code cards work by snooping the bus for any writes to port 0...
exactly what i was trying to say
haughty kite
i think that is what they do
thorn bramble
it can just intercept anything on the bus
haughty kite
but that doesnt explain pcie
thorn bramble
yeah, no, pci-e does io virtualization
so that must be a bit more complicated
or maybe not? who knows
haughty kite
legacy PCI is a normal bus i think
broken depot
According to a quick glance at the ol' search engine, PCIe doesn't support the same method of POST code card.
haughty kite
PCI express is some packet switched network memes
thorn bramble
yeah i don't think you can snoop around like that
haughty kite
and you wont find the legacy shit at all
wicked loom
ok sure but like
coolbird
the picture they showed when you all went like "haha can't work lmao", it was legacy PCI
on both counts
not PCIe
oh the second has PCIe on the side
i didn't even fucking notice it the first time around lmao
maybe that's for a different thing
not port 0x80 debugging
see how it has 2 displays
spice yarrow
@surreal path have you tried removing all the storage?
surreal path
<@787341689333350450> have you tried removing all the storage?
yea
why are we yapping in my thread about how to fix a broken laptop lol
its good
dw
about it
tmrw we sending it to the repair shop (if i dont sleep all day ofc like i did today)
also my bad for no nyaux development yesterday, it was just a shock that my laptop broke so wasnt in the mood to impl much other then adding a cpu id function into basic.h
silver yarrow
catch up on sleep now so u dont have to sleep when nyax dev
surreal path
i got my sleep
i slept all day lmao
anyways we do nyaux dev in like a bit im watching the new squid game rn lol
btw @silver yarrow u should watch the new squid game
its so good
anyways todo list today is:
improve scheduler queueing logic
figure out how tf does blocking threads work and impl that
if that was somehow done today then make uacpi use the scheduler to create threads that do work for it and such
if SOMEHOW i finish ALL of that today then its vfs time
finite summit
blocking threads is as shrimple as taking it off the run queue
silver yarrow
btw <@226721688203558913> u should watch the new squid game
ah I saw it but didnt feel like it watching it. Ill watch it on my flight home
finite summit
blocking threads is as shrimple as taking it off the run queue
and optionally, adding it to a list of waiters, if you are blocking for that reason
surreal path
blocking threads is as shrimple as taking it off the run queue
yes but HOW long is ze question
surreal path
and when do i do that lol
finite summit
and when do i do that lol
when you need to?
you don't just block threads for no reason
think back to the time you implemented interrupting waits in obos
surreal path
when you need to?
what is it just like a function thats like
unblockthread()
or some shi
finite summit
and what you saw there
pretty much
I call that function ThreadReady
because it makes the thread "ready for execution"
surreal path
what does uacpis waitforworkcompleteion do
surreal path
I call that function ThreadReady
and how does ur function know which blocked thread to make readyu
do u like take a handle or smt, tid? or like smt else
finite summit
it takes a struct thread*
finite summit
yes
surreal path
what does uacpis waitforworkcompleteion do
?
finite summit
usually when you block a thread, you put it on a list
finite summit
what does uacpis waitforworkcompleteion do
waits until all scheduled work is finished
surreal path
usually when you block a thread, you put it on a list
like blockedthreads
yea im getting u
finite summit
BUT
surreal path
waits until all scheduled work is finished
am i supposed to be constantly checking until the thread* doesnt exist
silver yarrow
@finite summit https://github.com/OBOS-dev/obos/blob/4cfb3751eab65210eee0686c231bf99c51c4042f/src/uACPI/kernel_api.c#L391 this should be base + len > ...
finite summit
think back to obos' struct waitable_header
surreal path
this list is not cpu-local
so its not cpu local but global?
finite summit
<@841762704766140486> https://github.com/OBOS-dev/obos/blob/4cfb3751eab65210eee0...
wrong obos
finite summit
so its not cpu local but global?
wrong
silver yarrow
wrong obos
oof
finite summit
think back to obos' `struct waitable_header`
.
spice yarrow
why are we yapping in my thread about how to fix a broken laptop lol
Because there's a ton of very smart people here and it's a very interesting problem
surreal path
😭
surreal path
Because there's a ton of very smart people here and it's a very interesting prob...
fairr
surreal path
gnu/obos when
silver yarrow
IT IS MASTER
finite summit
I thought it was master
wait it is
silver yarrow
lmao
finite summit
you're still on an old commit
silver yarrow
idfk
finite summit
yeah whatever
molten grotto
idk why you'd even check it
silver yarrow
😢
finite summit
yeah whatever
that function does nothing anyway
silver yarrow
lol
finite summit
well no wonder nyaux is cursed then
surreal path
💀
surreal path
in a lock, for example
like in
struct spinlock_t {
// spin lock stuff ^
struct waitable_header *hdr;
}
???
finite summit
not spin lock
surreal path
all my locks are spinlocks
silver yarrow
lol
molten grotto
when you acquire a spinlock you busy wait if its contended
surreal path
when you acquire a spinlock you busy wait if its contended
as in spin til its unlocked yea
molten grotto
when you acquire a mutex you block the thread (and switch to some other one) if its contended and then when the other thread unlockes the mutex it wakes you up again
surreal path
when you acquire a mutex you block the thread (and switch to some other one) if ...
oh so its like a lock multiple threads can have, and u block ze thread if its contended. im guessing in ze scheduler u check if its unlocked and if it is wake ze thread up
oh okayyyy
makes sense
finite summit
no
surreal path
oh i see
finite summit
so if a lock is contended (locked), you block the current thread, and add it to a list
then when the lock is unlocked, the mutex implementation will take that thread from the list
and wake it
surreal path
then when the lock is unlocked, the mutex implementation will take that thread f...
how does the futex know
like
if its code isnt being executed
finite summit
wut
molten grotto
know what
surreal path
as in
say u have a futex to something
okay ur a thread
u try to lock
uh oh its locked already
u block
right
finite summit
that's not what a futex is
surreal path
oh
finite summit
obos_status Sys_FutexWait(uint32_t *futex, uint32_t cmp_with, uint64_t timeout);
obos_status Sys_FutexWake(uint32_t *futex, uint32_t nWaiters);```if *futex==cmp_with, block the current thread, add it to a list
surreal path
cmp with?
finite summit
look at the god damn function
surreal path
im looking
finite summit
```c
obos_status Sys_FutexWait(uint32_t *futex, uint32_t cmp_with, uint64_t time...
then in wake, it chooses nWaiters threads that are waiting, and wakes them
finite summit
im looking
lies
surreal path
my eyes are staring
cmp with another futex?
what
no 1 why is it a u32
no 2
is it comparing with another futex or what
molten grotto
no
finite summit
no
molten grotto
it compares the value at *futex with a value that's also supplied to the syscall
you don't have to care about what the value is, its just an opaque 32-bit value the userspace supplies
finite summit
^
surreal path
you don't have to care about what the value is, its just an opaque 32-bit value ...
oh i see
finite summit
do I need to be extremely specific when I speak to nyauxmaster
finite summit
it compares the value at *futex with a value that's also supplied to the syscall
then it blocks the current thread if they don't match
iirc
surreal path
im sorry i struggle to understand things sometimes, like these concepts may seem trival to you but i never heard of this before so this is my first time learning this
struct futex {
uint32_t val;
struct waitable_hdr *hdr;
is it something like this
finite summit
not quite
molten grotto
then it blocks the current thread if they don't match
*if they match
surreal path
oop
finite summit
oop
because userspace only passes you a pointer
to an arbitrary place in memory
that's basically your futex handle
so you would basically have a map of uint32_t* futex to struct waitable_header*
at least that's what I do
and also what keyronex does (?)
surreal path
so you would basically have a map of `uint32_t* futex` to `struct waitable_heade...
and the deref of futex is the value
finite summit
and probably what a lot of other kernels do
finite summit
and the deref of futex is the value
yes
surreal path
would u have a global map of this?
finite summit
no
flat nymph
It gets fun when you have shared memory
surreal path
oh
flat nymph
It gets fun when you have shared memory
Between processes
molten grotto
would u have a global map of this?
per process for private futexes which are all you care about rn
surreal path
per process for private futexes which are all you care about rn
oh so each process has its own futex map thing
molten grotto
yes
finite summit
if (*futex == cmp_value)
block()
else
return EAGAIN```can't you have futexes on shared memory?
finite summit
```c
if (*futex == cmp_value)
block()
else
return EAGAIN```
that's basically what futex wait does
flat nymph
Anyway, futex is a mutex with "optimizations", which lets you not call kernel if only one thread is taking it (?)
surreal path
```c
if (*futex == cmp_value)
block()
else
return EAGAIN```
what is "egagain"
thorn bramble
EAGAIN is a posix error
finite summit
an errno value
surreal path
oh yea kk
surreal path
```c
if (*futex == cmp_value)
block()
else
return EAGAIN```
okay this makes sense now
finite summit
what it means is "retry the operation"
molten grotto
can't you have futexes on shared memory?
yes though you have to specifically not specify the FUTEX_PRIVATE flag when you wait/wake for that
flat nymph
Anyway, you probably need kernel mutexes
surreal path
Anyway, you probably need kernel mutexes
what
thorn bramble
☠️
flat nymph
What map
surreal path
uint32_t futex -> struct waitable_hdr
finite summit
*uint32_t*
molten grotto
*if they match
its actually a good thing that I got reminded of futexes and looked at my code, I spotted a mistake that I made when changing it around yesterday 
flat nymph
My kernel doesn't have futexes 
finite summit
its actually a good thing that I got reminded of futexes and looked at my code, ...
aren't aligned accesses to memory always atomic?
surreal path
uint32_t futex -> struct waitable_hdr
no i mean whats ze difference between kernel ones and non kernel ones
as u mentioned mishakov
finite summit
futex and mutex are difference
surreal path
oh
finite summit
*different
surreal path
whats the difference exactly
finite summit
everything
thorn bramble
aren't aligned accesses to memory always atomic?
not guaranteed on !x86
surreal path
bru
flat nymph
Futex is a type of mutex
molten grotto
aren't aligned accesses to memory always atomic?
on x86 yes but on other platforms like aarch64 no
finite summit
not guaranteed on !x86
oh
surreal path
Futex is a type of mutex
and whats a "normal mutex"
finite summit
I forgor about those arches
thorn bramble
still a good practice
flat nymph
on x86 yes but on other platforms like aarch64 no
Just spam barriers everywhere and you'll be set 
flat nymph
and whats a "normal mutex"
Something which blocks a thread and waits for it to be unlocked
surreal path
Something which blocks a thread and waits for it to be unlocked
and how does that work exactly
molten grotto
Just spam barriers everywhere and you'll be set <:tabien:820262543700394006>
Ill rather just do this proper thing 
flat nymph
Is mutex a particular case of semaphore? I don't remember
surreal path
bru and whats the normal impl of mutex
molten grotto
it can be used to implement a mutex
flat nymph
bru and whats the normal impl of mutex
None?
molten grotto
futex on its own is not a mutex
flat nymph
So, there are generally two types of locks
silver yarrow
the one in the car, and the one in the door
flat nymph
One is spinlock (there are many various implementations) which spins in a while loop and burns CPU untill it can be locked
surreal path
yea i have that
silver yarrow
I have many unintentional spinlocks
flat nymph
Or, instead of spinning, you can block the thread and do something else
Then when the other thread unlocks it, it will unblock the thread
This way you don't do "useless work" while waiting
And let other threads run
(kinda)
spinlocks also usually call sched_yield
but that's besides the point
Idk there should be some name for it let me google
Fun
surreal path
Then when the other thread unlocks it, it will unblock the thread
oh so like
if its locked already and u try to lock it block ze thread, otherwise lock it
if its unlocked by some thread, wake threads blocked waiting for ze lock
am i understanding this correctly THIS TIME
flat nymph
yes
like mutex is a lock which blocks the threads that haven't been able to acquire it
surreal path
is impl like, u have waitable header inside a mutex structure this time instead of a futex to waitable header, and the mutex contains a waitable header and the waitable header contains a list of blocked threads that tried to locked it but couldnt because the mutex was locked already
surreal path
okay so im guessing im wrong
fun
then how is mutex impl'd?
how is it shared between threads
how does it work
flat nymph
You want mutex for uACPI, right?
surreal path
yea
flat nymph
Not for userspace
surreal path
yea
flat nymph
I'm lost
flat nymph
is impl like, u have waitable header inside a mutex structure this time instead ...
As usual
Same as spinlock, but with ability to block threads
(btw spinlocks can also have lists )
surreal path
bro stop making this more complicated
flat nymph
That's what I was trying to explain the other day
surreal path
is mutex a structure that has a lock and a waitable hdr which contains shit like blocked threads yes or no
flat nymph
The simple impl is C struct mutex { spinlock lock; bool acquired; thread_t list_of_blocked_threads; }
flat nymph
is mutex a structure that has a lock and a waitable hdr which contains shit like...
yes
surreal path
thanks
thorny glen
spinlocks also usually call sched_yield
No no no
If you're in a context where you can yield then you should just use a blocking mutex
flat nymph
I disagree?
thorny glen
Why
flat nymph
blocking is much slower than yielding
thorny glen
Priorities
flat nymph
still, there are cases where spinlocks are preferable