Re: [GIT PULL v2] Scheduler enhancements for v6.14

[Ingo Molnar]

* Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> > > Since I booted the scheduler tree on generic desktops and it was 
> > > tested on other systems as well and nothing appeared to be 
> > > broken, I presume RSEQ_FLAG_UNREGISTER is used only in libc 
> > > syscall-testcases and in specific applications?
> > 
> > Nowadays, rseq unregistration is used by specialized applications 
> > (e.g. tcmalloc) which disable glibc rseq support with the glibc 
> > tunable and register it themselves. 
> > (GLIBC_TUNABLES=glibc.pthread.rseq=0)
> > 
> > A recent glibc (2.35+) don't use explicit rseq unregistration, it's 
> > unregistered implicitly when the thread exits.
> > 
> > I'll make a note to add a test case for 
> > GLIBC_TUNABLES=glibc.pthread.rseq=0 in the rseq selftests and 
> > librseq to improve test coverage when using a recent glibc.
> > 
> > We have all the code in there to use rseq unregistration, but it is 
> > skipped when glibc 2.35+ is handling the registration.
> 
> It turns out that it is covered by both librseq and glibc tests, just 
> not by the kernel rseq selftests:
> 
> librseq test: tests/syscall_errors_test.c
> glibc test: sysdeps/unix/sysv/linux/tst-rseq-disable.c
> 
> We should import the librseq test into the kernel rseq selftests as
> well. CCing Michael Jeanson who will take care of this.

Thank you! Linus just pulled the v2 pull request, so all should be good 
upstream.

	Ingo