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Some design of the cluster alloactor was later found to be improvable after thorough testing. For example, build kernel test with make -j96 and 10G ZRAM with 64kB mTHP enabled shows better performance and a lower failure rate: Before: sys time: 10230.22s 64kB/swpout: 1793044 64kB/swpout_fallback: 17653 After: sys time: 5538.3s 64kB/swpout: 1813133 64kB/swpout_fallback: 0 System time is cut in half, and the failure rate drops to zero. Larger allocations in a hybrid workload also showed a major improvement: 512kB swap failure rate: Before: swpout:11971 swpout_fallback:2218 After: swpout:14606 swpout_fallback:4 2M swap failure rate: Before: swpout:12 swpout_fallback:1578 After: swpout:1253 swpout_fallback:15 Kairui Song (2): mm, swap: don't scan every fragment cluster mm, swap: prefer nonfull over free clusters include/linux/swap.h | 1 - mm/swapfile.c | 68 +++++++++++++++++++++++--------------------- 2 files changed, 36 insertions(+), 33 deletions(-) -- 2.50.1