---- Original Message --- > v2->v3 > - Pass all test cases > - Introduce separate lock elision for rwlock > - Add performance comparison of cmap/hmap search > > v1->v2 > - Fix a bug at UNLOCK_ELISION > - Add checking if glibc version >= 2.21 (OVS_CHECK_GLIBC_TSX) > - Add checking of whether cpu has TSX support (OVS_CHECK_RTM) > - Enable LOCK_ELISION only when CPU has TSX and glibc doesn't > (if glibc version >= 2.21, then using phtread_mutex has lock elision) > - Add 20% mutation test-cmap testcase > - List failed testcases below > > The patch shows the preliminary results of enabling RTM > (Restricted Transactional Memory). A successful transactional execution > elides the lock, i.e., the lock is by-passed, and exposes concurrency. > However, transactions might abort due to several reasons > such as data conflicts, I/O operations, syscall, etc. When transaction aborts, > it falls back to the original locking mechanisms. Thus, the performance > improvement depends on the abort rate, and the overhead of speculative execution > and rollback. > > The patch adds ovs_##ELISION_FUNC at LOCK_FUNCTION, TRY_LOCK_FUNCTION, and > UNLOCK_FUNCTION macros, and calls either rwlock_elision or mutex_elision > accordingly. Experiments show that for cmap, the TM does not seem to have > observable improvements below 5% mutations, while hmap is more obvious. > For cmap search over 5% mutation, the search time of TM shows much better > scalability when % of writers increase.
This patch doesn't apply cleanly - will there be a rebase? Thanks in advance, Ryan Moats Results are shown by using test-cmap benchmark with different mutation %. $ tests/ovstest test-cmap benchmark 20000000 4 <mutation> 1 Unit: ms, number presented as baseline / TM <mutation> cmap_search hmap_search 0.1% 117/117 312/292 2% 124/120 688/328 5% 142/125 1093/403 10% 237/132 1588/432 20% 512/160 2516/679 40% 1010/277 2927/1007 60% 1278/324 3313/1119 80% 1614/343 3392/1291 Signed-off-by: William Tu <u9012...@gmail.com> --- configure.ac | 2 + lib/ovs-thread.c | 201 +++++++++++++++++++++++++++++++++++++++++++++++++ +---- m4/openvswitch.m4 | 21 ++++++ 3 files changed, 210 insertions(+), 14 deletions(-) _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
