This patch set added MCS lock library and its unit test. The MCS lock (proposed by JOHN M. MELLOR-CRUMMEY and MICHAEL L. SCOTT) provides scalability by spinning on a CPU/thread local variable which avoids expensive cache bouncings. It provides fairness by maintaining a list of acquirers and passing the lock to each CPU/thread in the order they acquired the lock.
References: 1. http://web.mit.edu/6.173/www/currentsemester/readings/R06-scalable-synchronization-1991.pdf 2. https://lwn.net/Articles/590243/ Mirco-benchmarking result: ------------------------------------------------------------------------------------------------ MCS lock | spinlock | ticket lock ------------------------------+--------------------------------+-------------------------------- Test with lock on 13 cores... | Test with lock on 14 cores... | Test with lock on 14 cores... Core [15] Cost Time = 22426 us| Core [14] Cost Time = 47974 us| Core [14] cost time = 66761 us Core [16] Cost Time = 22382 us| Core [15] Cost Time = 46979 us| Core [15] cost time = 66766 us Core [17] Cost Time = 22294 us| Core [16] Cost Time = 46044 us| Core [16] cost time = 66761 us Core [18] Cost Time = 22412 us| Core [17] Cost Time = 28793 us| Core [17] cost time = 66767 us Core [19] Cost Time = 22407 us| Core [18] Cost Time = 48349 us| Core [18] cost time = 66758 us Core [20] Cost Time = 22436 us| Core [19] Cost Time = 19381 us| Core [19] cost time = 66766 us Core [21] Cost Time = 22414 us| Core [20] Cost Time = 47914 us| Core [20] cost time = 66763 us Core [22] Cost Time = 22405 us| Core [21] Cost Time = 48333 us| Core [21] cost time = 66766 us Core [23] Cost Time = 22435 us| Core [22] Cost Time = 38900 us| Core [22] cost time = 66749 us Core [24] Cost Time = 22401 us| Core [23] Cost Time = 45374 us| Core [23] cost time = 66765 us Core [25] Cost Time = 22408 us| Core [24] Cost Time = 16121 us| Core [24] cost time = 66762 us Core [26] Cost Time = 22380 us| Core [25] Cost Time = 42731 us| Core [25] cost time = 66768 us Core [27] Cost Time = 22395 us| Core [26] Cost Time = 29439 us| Core [26] cost time = 66768 us | Core [27] Cost Time = 38071 us| Core [27] cost time = 66767 us ------------------------------+--------------------------------+-------------------------------- Total Cost Time = 291195 us | Total Cost Time = 544403 us | Total cost time = 934687 us ------------------------------------------------------------------------------------------------ Phil Yang (3): eal/mcslock: add mcs queued lock implementation eal/mcslock: use generic msc queued lock on all arch test/mcslock: add mcs queued lock unit test MAINTAINERS | 5 + app/test/Makefile | 1 + app/test/autotest_data.py | 6 + app/test/autotest_test_funcs.py | 32 +++ app/test/meson.build | 2 + app/test/test_mcslock.c | 248 +++++++++++++++++++++ doc/api/doxy-api-index.md | 1 + doc/guides/rel_notes/release_19_08.rst | 6 + lib/librte_eal/common/Makefile | 2 +- .../common/include/arch/arm/rte_mcslock.h | 23 ++ .../common/include/arch/ppc_64/rte_mcslock.h | 19 ++ .../common/include/arch/x86/rte_mcslock.h | 19 ++ .../common/include/generic/rte_mcslock.h | 169 ++++++++++++++ lib/librte_eal/common/meson.build | 1 + 14 files changed, 533 insertions(+), 1 deletion(-) create mode 100644 app/test/test_mcslock.c create mode 100644 lib/librte_eal/common/include/arch/arm/rte_mcslock.h create mode 100644 lib/librte_eal/common/include/arch/ppc_64/rte_mcslock.h create mode 100644 lib/librte_eal/common/include/arch/x86/rte_mcslock.h create mode 100644 lib/librte_eal/common/include/generic/rte_mcslock.h -- 2.7.4
