diff options
Diffstat (limited to 'Documentation/cgroups/memcg_test.txt')
| -rw-r--r-- | Documentation/cgroups/memcg_test.txt | 32 |
1 files changed, 5 insertions, 27 deletions
diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index 80ac454704b8..bcf750d3cecd 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -24,24 +24,7 @@ Please note that implementation details can be changed. a page/swp_entry may be charged (usage += PAGE_SIZE) at - mem_cgroup_charge_anon() - Called at new page fault and Copy-On-Write. - - mem_cgroup_try_charge_swapin() - Called at do_swap_page() (page fault on swap entry) and swapoff. - Followed by charge-commit-cancel protocol. (With swap accounting) - At commit, a charge recorded in swap_cgroup is removed. - - mem_cgroup_charge_file() - Called at add_to_page_cache() - - mem_cgroup_cache_charge_swapin() - Called at shmem's swapin. - - mem_cgroup_prepare_migration() - Called before migration. "extra" charge is done and followed by - charge-commit-cancel protocol. - At commit, charge against oldpage or newpage will be committed. + mem_cgroup_try_charge() 2. Uncharge a page/swp_entry may be uncharged (usage -= PAGE_SIZE) by @@ -69,19 +52,14 @@ Please note that implementation details can be changed. to new page is committed. At failure, charge to old page is committed. 3. charge-commit-cancel - In some case, we can't know this "charge" is valid or not at charging - (because of races). - To handle such case, there are charge-commit-cancel functions. - mem_cgroup_try_charge_XXX - mem_cgroup_commit_charge_XXX - mem_cgroup_cancel_charge_XXX - these are used in swap-in and migration. + Memcg pages are charged in two steps: + mem_cgroup_try_charge() + mem_cgroup_commit_charge() or mem_cgroup_cancel_charge() At try_charge(), there are no flags to say "this page is charged". at this point, usage += PAGE_SIZE. - At commit(), the function checks the page should be charged or not - and set flags or avoid charging.(usage -= PAGE_SIZE) + At commit(), the page is associated with the memcg. At cancel(), simply usage -= PAGE_SIZE. |