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Linux kernel hacker and maintainer etc.

OpenPGP: 3AB05486C7752FE1
jarkko

Jarkko Sakkinen

This performance regression fix is as done as it can be:

https://lore.kernel.org/linux-integrity/20240921120811.1264985-1-jarkko@kernel.org/

As soon as it gets tags I'll put out a pull request. Not having the fixes can double the boot time at least on some AMD desktop CPU's if TPM bus encryption is turned on.

Without fix: 7s -> 20s
WIth the fix: 20s -> 8.7s

So pretty reasonable number, encryption cannot be done without any overhead. Patches fixup unnecessary encryption context throttling.

Hopefully next week when the cons are over there will be some feedback.

#linux #kernel
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jarkko

Jarkko Sakkinen

Xenonauts 2 is a nice game, helps with Xcom withdrawal symptoms at least.
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jarkko

Jarkko Sakkinen

I got couple of days ago both email that my talk Linux Plumbers was both accepted and also that it was rejected šŸ¤· I guess there was something wrong with the mailer?

It would be nice to get infos a bit earlier and not in superposition state ;-)

@linuxplumbersconf
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jarkko

Jarkko Sakkinen

Julia is pretty cool language IMHO for doing workbook type of stuff like you would with Jupyter and all this "scientific Python" type of stuff. There's excellent support in the REPL cli for persistence with shared environments and projects. I think I replace bc and Python with Julia for being my main calculator app.
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jarkko

Jarkko Sakkinen

Edited 10 months ago
I tagged 0.1.0 of my TPM driver test framework: https://codeberg.org/jarkko/linux-tpmdd-test/src/tag/0.1.0

Now it pretty much can take care all testing and development needs I have. From this tag forward the Git history is also declared as stable (i.e. now rewrites).

It's also not that common example of using systemd with BuildRoot ;-)
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jarkko

Jarkko Sakkinen

I ended up with:

ftrace {
	event.kprobes {
		tpm_transmit {
			filters = "common_pid < 2"
			probes = "tpm_transmit"
			hist {
				keys = stacktrace
			}
		}
	}
}
kernel {
	trace_buf_size = 1M
	trace_options = sym-addr
}

It gives me counts of stack exercised during the boot. Iā€™d like to get latency calculation but Iā€™m not really good at this so this can do for the time being.

The is held in /sys/kernel/debug/tracing/events/kprobes/tpm_end/hist.

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jarkko

Jarkko Sakkinen

Edited 10 months ago
I voted in the Linux Foundation TAB elections.

Since it is politics I can tell that my top three was Dan Williams, Dave Hansen and Kees Cook and for the rest I gave equal vote.
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jarkko

Jarkko Sakkinen

Wondering if there is a reason for not having kernel-command line parameter for passing bootconfig. #linux #kernel
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jarkko

Jarkko Sakkinen

Noticed by accident in aerc. By pressing 's' you get a vertical pane showing the message instead of having to open it by pressing enter. By pressing 'shift-s' you get a horizontal pane.

#aerc #email
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jarkko

Jarkko Sakkinen

Edited 10 months ago
This was good stuff:

https://lwn.net/Articles/990273/
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jarkko

Jarkko Sakkinen

My pro tip for Amazon: if successful meetings are so important why not just require people to show up to those F2F?

I think staff would be more motivated with that constraint than enforced in-office weeks šŸ¤·

#amazon #remote #work
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jarkko
repeated
mattdm@hachyderm.io

Matthew Miller

Wow! Fedora Linux 41 beta today, _and_ twelve years at Red Hat for me!

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jarkko

Jarkko Sakkinen

Edited 10 months ago
After having MacBook Pro for 1.5 years from Tampere University picking the dev laptop for the new job was a no brainer options to pick being Macbook Pro or x86 Linux laptop.

MacOS is pure garbage a development environment. If you get one there is no other ways to make usable except installing Asahi Linux. Working with toolchains sucks, virtualization sucks and conceptually containers do not in reality exist.

I'm not even joking when I say that if i had picked Macbook Pro as my dev laptop for the new job it would statistically show in the performance reports over period of time as a negative impact. It just is super bad operating system for writing code.

I still love my personal Mac mini which is over-expensive audio plugin host :-) It does deliver in that task tho and works well also for watching Netflix.

Phew, it was nice to let all the hate for Macbook Pro out ;-) Piece of shit laptop tbh.
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jarkko

Jarkko Sakkinen

I was looking for something that would be a bit like Maple and Matlab for working as calculator, plotting and stuff like that but not as involved as those tools. After trying bunch of options I realized https://julialang.org/ is pretty much size-fit of this niche.
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jarkko

Jarkko Sakkinen

I like eBPF because it allows me to set conditions and measurement points so freely. A performance issue that took me some years ago two days to uncover takes now few hours. Improving tools brings so much more productivity than ChatGPT ever could.
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jarkko

Jarkko Sakkinen

I think I move my PR for v6.12 to late this week given that the getting performance improvements for TPM encryption are a priority to fix. Would not make sense to postpone them to v6.13 in my opinion.
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jarkko

Jarkko Sakkinen

First performance fixes for TPM HMAC encryption:

https://lore.kernel.org/linux-integrity/D4727YOJY8KZ.L6RKMRBKRCSN@kernel.org/T/#m22ed621c65c75c75900fe77c6b963ac98eb1b624

I don't expect this to fully address the performance challenges. It is the first axis here. Other axis is the session creation but these are independent issues.
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jarkko
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cmconseils@mastodon.social

Laura Manach bongoCat

Omg I'm laughing so much šŸ˜‚šŸ˜‚šŸ˜‚šŸ˜‚
https://onerpm.link/EatingTheCats

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jarkko

Jarkko Sakkinen

one of my favorite game themes: https://www.youtube.com/watch?v=ICX6hK3Se6k
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jarkko

Jarkko Sakkinen

Two weeks after this left at Tampere University working in https://sochub.fi/. Not that much is going to change to because I'm still happily stuck at my home and working on RISC-V peculiarities. It's a broken CPU architecture still in my opinion but that's why also fun to work with :-)
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