This patch series makes swapin readahead up to a certain number to gain more thp performance and adds tracepoint for khugepaged_scan_pmd, collapse_huge_page, __collapse_huge_page_isolate. This patch series was written to deal with programs that access most, but not all, of their memory after they get swapped out. Currently these programs do not get their memory collapsed into THPs after the system swapped their memory out, while they would get THPs before swapping happened. This patch series was tested with a test program, it allocates 800MB of memory, writes to it, and then sleeps. I force the system to swap out all. Afterwards, the test program touches the area by writing and leaves a piece of it without writing. This shows how much swap in readahead made by the patch. I've written down test results: With the patch: After swapped out: cat /proc/pid/smaps: Anonymous: 470760 kB AnonHugePages: 468992 kB Swap: 329244 kB Fraction: %99 After swapped in: In ten minutes: cat /proc/pid/smaps: Anonymous: 769208 kB AnonHugePages: 765952 kB Swap: 30796 kB Fraction: %99 Without the patch: After swapped out: cat /proc/pid/smaps: Anonymous: 238160 kB AnonHugePages: 235520 kB Swap: 561844 kB Fraction: %98 After swapped in: cat /proc/pid/smaps: In ten minutes: Anonymous: 499956 kB AnonHugePages: 235520 kB Swap: 300048 kB Fraction: %47 Ebru Akagunduz (3): mm: add tracepoint for scanning pages mm: make optimistic check for swapin readahead mm: make swapin readahead to improve thp collapse rate include/linux/mm.h | 4 ++ include/trace/events/huge_memory.h | 123 +++++++++++++++++++++++++++++++++++++ mm/huge_memory.c | 56 ++++++++++++++++- mm/memory.c | 2 +- 4 files changed, 181 insertions(+), 4 deletions(-) create mode 100644 include/trace/events/huge_memory.h -- 1.9.1 -- 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>