[lkml]   [2019]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC PATCH 0/2] mm/memcontrol: Finer-grained memory control
On 11.04.2019 17:55, Waiman Long wrote:
> On 04/11/2019 10:37 AM, Kirill Tkhai wrote:
>> On 10.04.2019 22:13, Waiman Long wrote:
>>> The current control mechanism for memory cgroup v2 lumps all the memory
>>> together irrespective of the type of memory objects. However, there
>>> are cases where users may have more concern about one type of memory
>>> usage than the others.
>>> We have customer request to limit memory consumption on anonymous memory
>>> only as they said the feature was available in other OSes like Solaris.
>>> To allow finer-grained control of memory, this patchset 2 new control
>>> knobs for memory controller:
>>> - memory.subset.list for specifying the type of memory to be under control.
>>> - memory.subset.high for the high limit of memory consumption of that
>>> memory type.
>>> For simplicity, the limit is not hierarchical and applies to only tasks
>>> in the local memory cgroup.
>>> Waiman Long (2):
>>> mm/memcontrol: Finer-grained control for subset of allocated memory
>>> mm/memcontrol: Add a new MEMCG_SUBSET_HIGH event
>>> Documentation/admin-guide/cgroup-v2.rst | 35 +++++++++
>>> include/linux/memcontrol.h | 8 ++
>>> mm/memcontrol.c | 100 +++++++++++++++++++++++-
>>> 3 files changed, 142 insertions(+), 1 deletion(-)
>> CC Andrey.
>> In Virtuozzo kernel we have similar functionality for limitation of page cache in a cgroup:
> It will be helpful to know the use case where you want to limit page
> cache usage. I have anonymous memory in mind when I compose this patch,
> but I make the mechanism more generic so that it can apply to other use
> cases as well.

We have distributed storage, and there are its daemons on every host.
There are replication factor 1:N, so the same block may be duplicated
on different hosts. They produce a lot of pagecache, but it is reused
not often (because of the above 1:N).

So, we want to limit pagecache, but do not limit anon memory. This
prevents global reclaim, and we found this improves our performance tests.


 \ /
  Last update: 2019-04-11 17:35    [W:0.066 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site