diff options
Diffstat (limited to 'Documentation/cgroups')
| -rw-r--r-- | Documentation/cgroups/memory.txt | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index e479007f1a7..6a066a270fc 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -184,12 +184,14 @@ behind this approach is that a cgroup that aggressively uses a shared page will eventually get charged for it (once it is uncharged from the cgroup that brought it in -- this will happen on memory pressure). +But see section 8.2: when moving a task to another cgroup, its pages may +be recharged to the new cgroup, if move_charge_at_immigrate has been chosen. + Exception: If CONFIG_CGROUP_CGROUP_MEM_RES_CTLR_SWAP is not used. When you do swapoff and make swapped-out pages of shmem(tmpfs) to be backed into memory in force, charges for pages are accounted against the caller of swapoff rather than the users of shmem. - 2.4 Swap Extension (CONFIG_CGROUP_MEM_RES_CTLR_SWAP) Swap Extension allows you to record charge for swap. A swapped-in page is @@ -615,8 +617,7 @@ memory cgroup. bit | what type of charges would be moved ? -----+------------------------------------------------------------------------ 0 | A charge of an anonymous page(or swap of it) used by the target task. - | Those pages and swaps must be used only by the target task. You must - | enable Swap Extension(see 2.4) to enable move of swap charges. + | You must enable Swap Extension(see 2.4) to enable move of swap charges. -----+------------------------------------------------------------------------ 1 | A charge of file pages(normal file, tmpfs file(e.g. ipc shared memory) | and swaps of tmpfs file) mmapped by the target task. Unlike the case of @@ -629,8 +630,6 @@ memory cgroup. 8.3 TODO -- Implement madvise(2) to let users decide the vma to be moved or not to be - moved. - All of moving charge operations are done under cgroup_mutex. It's not good behavior to hold the mutex too long, so we may need some trick. |