Jarkko Sakkinen
Posts
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Jarkko Sakkinen
jarkko
Great start for a year. I have a tech job. I've started to work on two new kernel features after some more quiet period. Could be worse.
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@jani
Jani 110% agree with you!
Like with anything I try to find some framework for measuring tools and then do the Excel job ;-)
If I had to make a "how to implement ANY feature to kernel" I would focus that too on measurement. Almost every time when it clicks inside your head how you take your test samples, also idea for implementation suddenly unrolls. It's pretty easy to then find what you need from kernel tree. Learning a slice of subsystem is 1% and forming the right question is 99%.
Jani 110% agree with you!
Like with anything I try to find some framework for measuring tools and then do the Excel job ;-)
If I had to make a "how to implement ANY feature to kernel" I would focus that too on measurement. Almost every time when it clicks inside your head how you take your test samples, also idea for implementation suddenly unrolls. It's pretty easy to then find what you need from kernel tree. Learning a slice of subsystem is 1% and forming the right question is 99%.
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Jarkko Sakkinen
jarkko
Edited 6 months ago
"leading programming language", "the most popular programming language" etc. Why it is a thing to rank this? I get gathering statistics but not it being an up-front thing.
I have not yet had a job where I would need such list for accomplishing anything :-)
Company/organization-wide decision making might need to look at such statistics for making long-term choices perhaps. It's pretty useless information overall...
I have not yet had a job where I would need such list for accomplishing anything :-)
Company/organization-wide decision making might need to look at such statistics for making long-term choices perhaps. It's pretty useless information overall...
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@Aissen It is my first from scratch driver since SGX driver. That project made me so exhausted that I'm actually happier now that I do my kernel things unpaid and out of passion only...
Previously a professional kernel developer. Now probably like con artist or crypto scam specialist, since isn't everyone working blockchains something like that :-) I also have TPM2 asymmetric keys in progress but it is paused for a while (as this feels more inspiring for the moment).
Previously a professional kernel developer. Now probably like con artist or crypto scam specialist, since isn't everyone working blockchains something like that :-) I also have TPM2 asymmetric keys in progress but it is paused for a while (as this feels more inspiring for the moment).
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Jarkko Sakkinen
jarkko
@Aissen Looking at existing code base for the loopback driver, I'd find any excuse not to review it because it would be too much work to tell all the details "what needs to be done".
So I believe that once there is a cleaner driver and easy to run test program, and legit use NON-PROPRIETARY use cases clearly explained, also maintainers give less hate :-) And today companies have started to anyway prefer in-tree drivers more, as it is just plain more practical and cheaper over long period of time. We are big enough, and your proprietary crap will be made obsolete by competitors.
So I believe that once there is a cleaner driver and easy to run test program, and legit use NON-PROPRIETARY use cases clearly explained, also maintainers give less hate :-) And today companies have started to anyway prefer in-tree drivers more, as it is just plain more practical and cheaper over long period of time. We are big enough, and your proprietary crap will be made obsolete by competitors.
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@Aissen lol and at least FSF does not have a campaign against this ;-) I don't get how they still today campaign against TPM. https://www.defectivebydesign.org/dayagainstdrm
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Jarkko Sakkinen
jarkko
@Aissen It's really a project where 80% is doing other than kernel code and 20% is the kernel challenge. I pretty much know how to do the API shift but I need to finish up this test program first :-) We have done something quite close e.g. in tpm_vtpm_proxy.
And yeah, it's like the meat is great but it is surrounded by a broken framework so you need to do small steps and run the test for every single iteration. It's too easy otherwise to look at a piece of code and decide that it is crap and remove something actually relevant :-)
And yeah, it's like the meat is great but it is surrounded by a broken framework so you need to do small steps and run the test for every single iteration. It's too easy otherwise to look at a piece of code and decide that it is crap and remove something actually relevant :-)
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@Aissen there's libcamera and pipewire etc. but what people actually use is a tainted driver ;-) in their work machines. i don't really fully believe that proprietary driver story in 2024 given how many things you can anyway do in user space so not stopping based on this doing a RFC patch TBH (if that was the recommendation).
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Jarkko Sakkinen
jarkko
@Aissen it is based on that fixes up the device model https://social.kernel.org/notice/ApXBpAVuAyGBmcPye8
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Jarkko Sakkinen
jarkko
Great found the most suitable crate for my test program:
https://github.com/zesterer/euc
I.e. I can pre-render the frame to buffers and then loop those frames to "cast_fd" with a given FPS (25) so it should be fairly timing accurate.
Using rotating and shaded torus I have cyclic movement which the other side (opening /dev/video0) can then read and store a full cycle of the animation.
Client and server can be two threads in the same process, and as final step the client can compare that the read frames are close proximity enough to the pre-rendered frames.
That should create a full headless and "CI friendly" system test for v4l2-cast. Definitely still hold a bit before doing too heavy refactoring and make this happen!
I wonder can we already have Rust programs in kselftest's? My driver is in C but this could be potentially part of the kselftest (at some point).
#linux #kernel #video4linux
https://github.com/zesterer/euc
I.e. I can pre-render the frame to buffers and then loop those frames to "cast_fd" with a given FPS (25) so it should be fairly timing accurate.
Using rotating and shaded torus I have cyclic movement which the other side (opening /dev/video0) can then read and store a full cycle of the animation.
Client and server can be two threads in the same process, and as final step the client can compare that the read frames are close proximity enough to the pre-rendered frames.
That should create a full headless and "CI friendly" system test for v4l2-cast. Definitely still hold a bit before doing too heavy refactoring and make this happen!
I wonder can we already have Rust programs in kselftest's? My driver is in C but this could be potentially part of the kselftest (at some point).
#linux #kernel #video4linux
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