Re: [RFC][PATCH] the proposal of improve page reclaim by throttle

[Balbir Singh <balbir@linux.vnet.ibm.com>]

KOSAKI Motohiro wrote:
> Hi balbir-san
> 
>>  It's good to keep the main reclaim code and the memory controller reclaim in
>>  sync, so this is a nice effort.
> 
> thank you.
> I will repost next version (fixed nick's opinion) while a few days.
> 
>>  > @@ -1456,7 +1501,7 @@ unsigned long try_to_free_mem_cgroup_pag
>>  >       int target_zone = gfp_zone(GFP_HIGHUSER_MOVABLE);
>>  >
>>  >       zones = NODE_DATA(numa_node_id())->node_zonelists[target_zone].zones;
>>  > -     if (do_try_to_free_pages(zones, sc.gfp_mask, &sc))
>>  > +     if (try_to_free_pages_throttled(zones, 0, sc.gfp_mask, &sc))
>>  >               return 1;
>>  >       return 0;
>>  >  }
>>
>>  try_to_free_pages_throttled checks for zone_watermark_ok(), that will not work
>>  in the case that we are reclaiming from a cgroup which over it's limit. We need
>>  a different check, to see if the mem_cgroup is still over it's limit or not.
> 
> That makes sense.
> 
> unfortunately, I don't know mem-cgroup so much.
> What do i use function, instead?

One option could be that once the memory controller has this feature, we'll need
no changes in try_to_free_mem_cgroup_pages.

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL