Userspace RCU

x86 32/64 is done.

s390/s390x is done.

For power8 and aarch64, will need to bind to arch-specific headers rather than "gcc", but still use the generic atomic implementation.

powerpc 32/64 (except power8) is done.

For ia64, will need to create arch-specific header, and still use gcc generic atomics.

tile needs own arch-specific header, which use generic atomics.

arm system call has been pulled into Linux. Should be added to urcu.

arm32 is done.

power8 is done.

aarch64 is done.

ia64 is done.

tile is done.

Architectures not yet available at kernel level but present in urcu: alpha, hppa, mips, sparc64.

MIPS syscalls are merged into mainline kernel, however since there are 3 mips ABIs, wiring them up in urcu is not straightforward and would require access to MIPS boards for testing.

hppa is done.

sparc64 is done.

Still missing: MIPS (there are about 3 ABIs, not trivial, need testing). alpha (syscall not wired in the kernel).

https://review.lttng.org/c/userspace-rcu/+/7451

So only MIPS appears to be missing at this point, mostly because we don't have any test boards in our CI:

MIPS membarrier system call in the upstream kernel:

kernel/syscalls/syscall_n64.tbl
329:318    n64    membarrier            sys_membarrier

kernel/syscalls/syscall_n32.tbl
333:322    n32    membarrier            sys_membarrier

kernel/syscalls/syscall_o32.tbl
372:358    o32    membarrier            sys_membarrier