Messages in this thread | | | From | Yang Shi <> | Subject | [RFC v3 PATCH 0/5] mm: memcontrol: do memory reclaim when offlining | Date | Thu, 10 Jan 2019 03:14:40 +0800 |
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We have some usecases which create and remove memcgs very frequently, and the tasks in the memcg may just access the files which are unlikely accessed by anyone else. So, we prefer force_empty the memcg before rmdir'ing it to reclaim the page cache so that they don't get accumulated to incur unnecessary memory pressure. Since the memory pressure may incur direct reclaim to harm some latency sensitive applications.
Force empty would help out such usecase, however force empty reclaims memory synchronously when writing to memory.force_empty. It may take some time to return and the afterwards operations are blocked by it. Although this can be done in background, some usecases may need create new memcg with the same name right after the old one is deleted. So, the creation might get blocked by the before reclaim/remove operation.
Delaying memory reclaim in cgroup offline for such usecase sounds reasonable. Introduced a new interface, called wipe_on_offline for both default and legacy hierarchy, which does memory reclaim in css offline kworker.
v2 -> v3: * Introduced may_swap parameter to mem_cgroup_force_empty() to keep force_empty behavior per Shakeel * Fixed some comments from Shakeel
v1 -> v2: * Introduced wipe_on_offline interface suggested by Michal * Bring force_empty into default hierarchy
Patch #1: Fix some obsolete information about force_empty in the document Patch #2: Introduce may_swap parameter to mem_cgroup_force_empty() Patch #3: Introduces wipe_on_offline interface Patch #4: Being force_empty into default hierarchy Patch #5: Document update
Yang Shi (5): doc: memcontrol: fix the obsolete content about force empty mm: memcontrol: add may_swap parameter to mem_cgroup_force_empty() mm: memcontrol: introduce wipe_on_offline interface mm: memcontrol: bring force_empty into default hierarchy doc: memcontrol: add description for wipe_on_offline
Documentation/admin-guide/cgroup-v2.rst | 23 ++++++++++++++++++++ Documentation/cgroup-v1/memory.txt | 17 ++++++++++++--- include/linux/memcontrol.h | 3 +++ mm/memcontrol.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++----- 4 files changed, 98 insertions(+), 8 deletions(-)
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