On Tue, 8 Aug 2023 10:08:58 -0700 Stefan Roesch <shr@xxxxxxxxxxxx> wrote: > With madvise and prctl KSM can be enabled for different VMA's. Once it > is enabled we can query how effective KSM is overall. However we cannot > easily query if an individual VMA benefits from KSM. > > This commit adds a KSM section to the /prod/<pid>/smaps file. It reports > how many of the pages are KSM pages. > > Here is a typical output: > > 7f420a000000-7f421a000000 rw-p 00000000 00:00 0 > Size: 262144 kB > KernelPageSize: 4 kB > MMUPageSize: 4 kB > Rss: 51212 kB > Pss: 8276 kB > Shared_Clean: 172 kB > Shared_Dirty: 42996 kB > Private_Clean: 196 kB > Private_Dirty: 7848 kB > Referenced: 15388 kB > Anonymous: 51212 kB > KSM: 41376 kB > LazyFree: 0 kB > AnonHugePages: 0 kB > ShmemPmdMapped: 0 kB > FilePmdMapped: 0 kB > Shared_Hugetlb: 0 kB > Private_Hugetlb: 0 kB > Swap: 202016 kB > SwapPss: 3882 kB > Locked: 0 kB > THPeligible: 0 > ProtectionKey: 0 > ksm_state: 0 > ksm_skip_base: 0 > ksm_skip_count: 0 > VmFlags: rd wr mr mw me nr mg anon > > This information also helps with the following workflow: > - First enable KSM for all the VMA's of a process with prctl. > - Then analyze with the above smaps report which VMA's benefit the most > - Change the application (if possible) to add the corresponding madvise > calls for the VMA's that benefit the most smaps is documented in Documentation/filesystems/proc.rst, please. (And it looks a bit out of date). Did you consider adding this info to smaps_rollup as well?
