Messages in this thread | | | From | David Laight <> | Subject | RE: ftrace not showing the process names for all processes on syscall events | Date | Wed, 1 Apr 2020 14:37:28 +0000 |
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From: David Laight > Sent: 30 March 2020 19:15 > From: Steven Rostedt > > Sent: 30 March 2020 19:08 > > On Mon, 30 Mar 2020 15:34:08 +0000 > > David Laight <David.Laight@ACULAB.COM> wrote: > > > > > Oh, does the 'function_graph' code ignore tail calls? > > > > Yes and no ;-) It works by dumb luck. As it was a year after function > > graph tracing was live (some time in 2010 I believe) that someone brought > > up tail calls, and I had to take a look at how it never crashed, and was > > surprised that it "just worked". Here's a summary: > > 'Dumb luck' seems to be failing me :-) > I'll look more closely tomorrow.
The 'problem' is that some files like lib/iov_iter.c don't have the tracepoints compiled in.
So calls I was expecting to see were absent.
David
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