sched.h, sched_getcpu(), sched_get/setaffinity()

[kib]

Summary

Add real sched.h

It is required by IEEE Std 1003.1-2008 AKA POSIX.

Put some Linux compatibility stuff under BSD_VISIBLE namespace, in
particular, sys/cpuset.h definitions.  Also, if user really want
Linux compatibility, she can request cpu_set_t typedef with
_WITH_CPU_SET_T define.

Add sched_get/setaffinity
 
 for compatibility with Linux. [*]

• Yes I know that this is racy. The API is needed for providing seed for D32505

Add sched_getcpu()

for compatibility with Linux.

x86: provide userspace implementation of sched_getcpu() where possible

sched.h: add CPU_EQUAL() for better compatibility with Linux

[brooks]

sys/kern/syscalls.master

3265–3267 ↗

(On Diff #98226)

[jhb]

lib/libc/x86/sys/sched_getcpu_x86.c

58 ↗

(On Diff #98226)

Do we already store the FreeBSD CPU-ID in the MSR that rdtscp returns in %rcx I guess? Ah, yes, we do in initializecpu(). It seems that is the same thing rdpid returns as well.

[kib]

lib/libc/x86/sys/sched_getcpu_x86.c

58 ↗

(On Diff #98226)

Yes we do, I added it several years ago.