This series adds the __aligned attribute to atomic_t and atomic64_t. It also adds a Kconfig option to enable a new runtime warning to help reveal misaligned atomic accesses on platforms which don't trap that. Some people might assume scalars are aligned to 4-byte boundaries, while others might assume natural alignment. Best not to encourage such assumptions. Moreover, being that locks are performance sensitive, and being that atomic operations tend to involve further assumptions, there seems to be room for improvement here. Pertinent to this discussion are the section "Memory Efficiency" in Documentation/RCU/Design/Requirements/Requirements.rst and the section "GUARANTEES" in Documentation/memory-barriers.txt Finn Thain (2): documentation: Discourage alignment assumptions atomic: Specify alignment for atomic_t and atomic64_t Peter Zijlstra (1): atomic: Add alignment check to instrumented atomic operations Documentation/core-api/unaligned-memory-access.rst | 7 ------- include/asm-generic/atomic64.h | 2 +- include/linux/instrumented.h | 4 ++++ include/linux/types.h | 2 +- lib/Kconfig.debug | 10 ++++++++++ 5 files changed, 16 insertions(+), 9 deletions(-) -- 2.49.1
