ANNOUNCE: The following has been released:

trace-cmd 3.2.2

libtracefs 1.8.2

A ftrace selftest just failed due to the differences between bash and dash on how they interpret backslashes (\).

Bash will evaluate it once, where as dash will evaluate it every time.

i=123
TEST="\\$i"
echo "$TEST"

Bash will show: \123

where as dash will echo out the escape sequence of “123”.

A kprobe event self test needed to test the max number of arguments, where each argument held a backslash followed by a number. It created it with the loop:

   TEST_STRING=$1
   # Acceptable
   for i in `seq 1 $MAX_ARGS`; do
    TEST_STRING="$TEST_STRING \\$i"
   done
   echo "$TEST_STRING" >> dynamic_events

Which worked fine when /bin/sh was bash, but when /bin/sh was dash, it failed!

And checkbashisms did NOT catch it!

Just added tab completion for trace-cmd sqlhist for making synthetic events with the sql interface so much easier!

I’ve been wanting to add to trace-cmd start a way to make it start quicker. It’s currently slow because it resets most of tracefs before starting, and that can take seconds.

I forgot I already have this feature! trace-cmd set acts just like start, but it does not do the reset before starting. It’s very quick!

Note, it also does not re-enable tracing if it’s disabled. So you may want to run trace-cmd restart right after that, if that’s the case.

Another email sent to the Linux Plumbers mailing list:

"Hi there,

This is Jacob Bryant and I came across the helpful information you shared on the lpc.events website and was wondering if you were open to adding new resources to your page.

Unfortunately, plumbers are at a higher risk of being diagnosed with mesothelioma, a rare cancer caused from exposure to asbestos that takes 20-50 years to develop. It’s extremely important that those who have and are working in plumbing are aware of this type of cancer. That's why we made a guide that covers everything you need to know about mesothelioma as a plumber."

From all the times Linus has yelled "Christ!" at my emails, I feel like I should become a missionary.

I received an email from my test suite that it failed while I was on the plane waiting for everyone to board. I ssh'd into my server with the Connect app, found it was a configuration issue, fixed the configuration and restarted the tests, before they closed the aircraft door!

-Werror is great, until you need to debug an older kernel 😛

This meme perfectly describes pretty much every interaction between Linus Torvalds and myself!

I think this is the first time I ever used the quadratic equation for a real purpose since college! 🤔

https://lore.kernel.org/lkml/20250204172045.3a5d8d01@gandalf.local.home/

Not every day you can say you were complemented by Linus Torvalds saying you had an “interesting idea”. Always look for those silver linings!

https://lore.kernel.org/linux-trace-kernel/20241217131717.0fa5a21b@gandalf.local.home/T/#med0de149d3f7d1d4648406c277272ff6ea9eab04

Fixing up a messed up Debian upgrade where I needed to reinstall, I had to hit “Select this only if you know what you are doing”. I don’t know what I’m doing, but I had to hit it to do what I needed to get done 😛

Another useful email to the Linux Plumbers mailing list!

Kernel Recipes (which is always held in Paris) is thinking of changing their logo.

Last night at the real-time celebration, Thomas Gleixner handed Linus Torvalds his official pull request of the real-time patch on paper "wrapped in gold with a ribbon around it''

THIS IS IT!!!

The last hurdle for PREEMPT_RT being merged into mainline has just removed by this pull request. Leaving the door open for PREEMPT_RT to be added to 6.12!

With my new persistent memory mapped ring buffer, were I can retrieve the tracing buffer from the previous boot that crashed, I was able to debug a recent issue. To do this, I added code to allow trace_printk() to be directed to the persistent ring buffer, along with enabling the printk console trace event (writes all printk()s to the tracing ring buffer), I was able to get the perfect idea of what was happening that lead up to the crash!

https://lore.kernel.org/lkml/20240823013902.135036960@goodmis.org/

ANNOUNCE Just released:

trace-cmd v3.3 and libtracecmd 1.5.2

libtracefs v1.8.1

libtraceevent v1.8.3

A tribute to Daniel Bristot de Oliveira from Linux Plumbers. https://lpc.events/blog/current/index.php/2024/07/06/in-memory-of-daniel-bristot-de-oliveira/

Daniel Bristot de Oliveira passed away on Monday, June 24th at the age of 37. Another sad loss for the Linux kernel developer community, Daniel will be sorely missed.

In memory of Daniel: https://t.co/kQCQyTCo1a