X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=Documentation%2Fcontrollers%2Fmemory.txt;h=1c07547d3f81f28a19edb9de8752f8865b44478d;hb=92b29b86fe2e183d44eb467e5e74a5f718ef2e43;hp=866b9cd9a9590d6b6b8c3d577038e8d51234082b;hpb=2f633928cbba8a5858bb39b11e7219a41b0fbef5;p=mv-sheeva.git diff --git a/Documentation/controllers/memory.txt b/Documentation/controllers/memory.txt index 866b9cd9a95..1c07547d3f8 100644 --- a/Documentation/controllers/memory.txt +++ b/Documentation/controllers/memory.txt @@ -112,14 +112,22 @@ the per cgroup LRU. 2.2.1 Accounting details -All mapped pages (RSS) and unmapped user pages (Page Cache) are accounted. -RSS pages are accounted at the time of page_add_*_rmap() unless they've already -been accounted for earlier. A file page will be accounted for as Page Cache; -it's mapped into the page tables of a process, duplicate accounting is carefully -avoided. Page Cache pages are accounted at the time of add_to_page_cache(). -The corresponding routines that remove a page from the page tables or removes -a page from Page Cache is used to decrement the accounting counters of the -cgroup. +All mapped anon pages (RSS) and cache pages (Page Cache) are accounted. +(some pages which never be reclaimable and will not be on global LRU + are not accounted. we just accounts pages under usual vm management.) + +RSS pages are accounted at page_fault unless they've already been accounted +for earlier. A file page will be accounted for as Page Cache when it's +inserted into inode (radix-tree). While it's mapped into the page tables of +processes, duplicate accounting is carefully avoided. + +A RSS page is unaccounted when it's fully unmapped. A PageCache page is +unaccounted when it's removed from radix-tree. + +At page migration, accounting information is kept. + +Note: we just account pages-on-lru because our purpose is to control amount +of used pages. not-on-lru pages are tend to be out-of-control from vm view. 2.3 Shared Page Accounting @@ -242,8 +250,7 @@ rmdir() if there are no tasks. 1. Add support for accounting huge pages (as a separate controller) 2. Make per-cgroup scanner reclaim not-shared pages first 3. Teach controller to account for shared-pages -4. Start reclamation when the limit is lowered -5. Start reclamation in the background when the limit is +4. Start reclamation in the background when the limit is not yet hit but the usage is getting closer Summary