[RELEASE] Userspace RCU 0.15.5

Hi,

This is the 0.15.5 release of liburcu. The most relevant
change introduced by this release is the use of
"lock; addl" to replace the "mfence" instruction for
cmm_smp_mb() on x86-64 when users build liburcu without
"compiler builtins" atomics. Users wishing to synchronize
with I/O already need to use cmm_mb().

This is motivated by the fact that "lock; addl" is significantly
faster than "mfence".

Detailed changelog:

2025-11-10 Userspace RCU 0.15.5
         * x86: Define cmm_smp_mb() as lock; addl rather than mfence
         * Introduce barrier test
         * Add test_uatomic to gitignore
         * Cleanup: Remove stray space
         * benchmark: Add uatomic benchmark

Project website: https://liburcu.org
Git repository: https://git.liburcu.org/userspace-rcu.git

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com