In this patch series, we separated out the MCS lock code which was previously embedded in the mutex.c. This allows for easier reuse of MCS lock in other places like rwsem and qrwlock. We also did some micro optimizations and barrier cleanup. The original code has potential leaks between critical sections, which was not a problem when MCS was embedded within the mutex but needs to be corrected when allowing the MCS lock to be used by itself for other locking purposes. Proper barriers are now embedded with the usage of smp_load_acquire() in mcs_spin_lock() and smp_store_release() in mcs_spin_unlock. See http://marc.info/?l=linux-arch&m=138386254111507 for info on the new smp_load_acquire() and smp_store_release() functions. This patches were previously part of the rwsem optimization patch series but now we spearate them out. We have also added hooks to allow for architecture specific implementation of the mcs_spin_lock and mcs_spin_unlock functions. Will, do you want to take a crack at adding implementation for ARM with wfe instruction? Tim v6: 1. Fix a bug of improper xchg_acquire and extra space in barrier fixing patch. 2. Added extra hooks to allow for architecture specific version of mcs_spin_lock and mcs_spin_unlock to be used. v5: 1. Rework barrier correction patch. We now use smp_load_acquire() in mcs_spin_lock() and smp_store_release() in mcs_spin_unlock() to allow for architecture dependent barriers to be automatically used. This is clean and will provide the right barriers for all architecture. v4: 1. Move patch series to the latest tip after v3.12 v3: 1. modified memory barriers to support non x86 architectures that have weak memory ordering. v2: 1. change export mcs_spin_lock as a GPL export symbol 2. corrected mcs_spin_lock to references Jason Low (1): MCS Lock: optimizations and extra comments Tim Chen (2): MCS Lock: Restructure the MCS lock defines and locking code into its own file MCS Lock: Allows for architecture specific mcs lock and unlock Waiman Long (2): MCS Lock: Move mcs_lock/unlock function into its own file MCS Lock: Barrier corrections arch/Kconfig | 3 ++ include/linux/mcs_spinlock.h | 30 +++++++++++++ include/linux/mutex.h | 5 ++- kernel/locking/Makefile | 6 +-- kernel/locking/mcs_spinlock.c | 98 +++++++++++++++++++++++++++++++++++++++++++ kernel/locking/mutex.c | 60 ++++---------------------- 6 files changed, 144 insertions(+), 58 deletions(-) create mode 100644 include/linux/mcs_spinlock.h create mode 100644 kernel/locking/mcs_spinlock.c -- 1.7.11.7 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>