Hi Piscium, Second attempt, the first went to the old list address.

What I posted before was just a short snippet. In the link below there is a trace for leafpad, available for 7 days. https://we.tl/t-BAbO60lnGN

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I suggest using the simplest X client you can which shows the issue, e.g. xev(1). ... Good suggestion. I tried xev and I cannot reproduce the issue. The simplest app that I tried that shows the issue is leafpad.

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The second, if you read the two other emails in the thread, fixes the problem by changing the kernel's clock source which may differ between your two test machines?

I am not sure what you are referring to, maybe a link for the second page is missing?

Sorry. https://www.mail-archive.com/debian-bugs-dist@lists.debian.org/msg1823248.ht...

There are tons of GUI apps. I have tested just a handful of them. Have the clock_gettime issue: leafpad, mousepad, emacs, audacious, konsole. Don't have the issue: xev, xterm.

I tried to figure out if there is a common library used by all apps that have the problem but so far have not found it. A way to figure this out might be using gdb and putting a breakpoint on clock_gettime, but i am reluctant to do this as it would take a lot of time

It may be perf_events would help you analyse the frequency of difference clock_gettime() callers, say by maintaining frequency counts of the previous three functions in the call stack, but I don't know enough to suggest how. https://www.brendangregg.com/perf.html -- Cheers, Ralph.