This patchset extends the work started by Ingo Molnar in late 2012, optimizing the anon-vma mutex lock, converting it from a exclusive mutex to a rwsem, and sharing the lock for read-only paths when walking the the vma-interval tree. More specifically commits 5a505085 and 4fc3f1d6. The i_mmap mutex has similar responsibilities with the anon-vma, protecting file backed pages. Therefore we can use similar locking techniques: covert the mutex to a rwsem and share the lock when possible. With these changes, and the rwsem optimizations discussed in http://lkml.org/lkml/2013/6/16/38 we can see performance improvements. For instance, on a 8 socket, 80 core DL980, when compared to a vanilla 3.10-rc5, aim7 benefits in throughput, with the following workloads (beyond 500 users): - alltests (+14.5%) - custom (+17%) - disk (+11%) - high_systime (+5%) - shared (+15%) - short (+4%) For lower amounts of users, there are no significant differences as all numbers are within the 0-2% noise range. Davidlohr Bueso (5): mm,fs: introduce helpers around i_mmap_mutex mm: use new helper functions around the i_mmap_mutex mm: convert i_mmap_mutex to rwsem mm/rmap: share the i_mmap_rwsem mm: rename leftover i_mmap_mutex Documentation/lockstat.txt | 2 +- Documentation/vm/locking | 2 +- arch/x86/mm/hugetlbpage.c | 6 +++--- fs/hugetlbfs/inode.c | 4 ++-- fs/inode.c | 2 +- include/linux/fs.h | 22 +++++++++++++++++++++- include/linux/mmu_notifier.h | 2 +- kernel/events/uprobes.c | 6 +++--- kernel/fork.c | 4 ++-- mm/filemap.c | 10 +++++----- mm/filemap_xip.c | 4 ++-- mm/fremap.c | 4 ++-- mm/hugetlb.c | 16 ++++++++-------- mm/memory-failure.c | 7 +++---- mm/memory.c | 8 ++++---- mm/mmap.c | 22 +++++++++++----------- mm/mremap.c | 6 +++--- mm/nommu.c | 14 +++++++------- mm/rmap.c | 24 ++++++++++++------------ 19 files changed, 92 insertions(+), 73 deletions(-) -- 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>