This patchset modifies the qspinlock code to allow it to store the lock holder cpu number in the lock itself if feasible for easier debugging and crash dump analysis. This lock holder cpu information may also be useful to architectures like PowerPC that needs the lock holder cpu number for better paravirtual spinlock performance. A new config option QUEUED_SPINLOCKS_CPUINFO is added. If this config option is set, lock holder cpu number will always be stored if the number is small enough. Without this option, lock holder cpu number will only be stored in the slowpath of the native qspinlock. Waiman Long (2): locking/qspinlock: Store lock holder cpu in lock if feasible locking/pvqspinlock: Optionally store lock holder cpu into lock arch/Kconfig | 12 ++++++ arch/x86/include/asm/qspinlock_paravirt.h | 9 ++-- include/asm-generic/qspinlock.h | 13 ++++-- include/asm-generic/qspinlock_types.h | 5 +++ kernel/locking/qspinlock.c | 50 +++++++++++++++-------- kernel/locking/qspinlock_paravirt.h | 41 ++++++++++--------- 6 files changed, 87 insertions(+), 43 deletions(-) -- 2.18.1
