Pull futex updates from Thomas Gleixner:
- Switch the reference counting to a RCU based per-CPU reference to
address a performance bottleneck vs the single instance rcuref
variant
- Make the futex selftest build on 32-bit architectures which only
support 64-bit time_t, e.g. RISCV-32
- Cleanups and improvements in selftests and futex bench
* tag 'locking-futex-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests/futex: Fix spelling mistake "Succeffuly" -> "Successfully"
selftests/futex: Define SYS_futex on 32-bit architectures with 64-bit time_t
perf bench futex: Remove support for IMMUTABLE
selftests/futex: Remove support for IMMUTABLE
futex: Remove support for IMMUTABLE
futex: Make futex_private_hash_get() static
futex: Use RCU-based per-CPU reference counting instead of rcuref_t
selftests/futex: Adapt the private hash test to RCU related changes