Re: [PATCH 08/10] memcg: add cgroupfs interface to memcg dirtylimits

From: KAMEZAWA Hiroyuki
Date: Tue Oct 05 2010 - 03:19:07 EST


On Sun, 3 Oct 2010 23:58:03 -0700
Greg Thelen <gthelen@xxxxxxxxxx> wrote:

> Add cgroupfs interface to memcg dirty page limits:
> Direct write-out is controlled with:
> - memory.dirty_ratio
> - memory.dirty_bytes
>
> Background write-out is controlled with:
> - memory.dirty_background_ratio
> - memory.dirty_background_bytes
>
> Signed-off-by: Andrea Righi <arighi@xxxxxxxxxxx>
> Signed-off-by: Greg Thelen <gthelen@xxxxxxxxxx>

Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>

a question below.


> ---
> mm/memcontrol.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 89 insertions(+), 0 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6ec2625..2d45a0a 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -100,6 +100,13 @@ enum mem_cgroup_stat_index {
> MEM_CGROUP_STAT_NSTATS,
> };
>
> +enum {
> + MEM_CGROUP_DIRTY_RATIO,
> + MEM_CGROUP_DIRTY_BYTES,
> + MEM_CGROUP_DIRTY_BACKGROUND_RATIO,
> + MEM_CGROUP_DIRTY_BACKGROUND_BYTES,
> +};
> +
> struct mem_cgroup_stat_cpu {
> s64 count[MEM_CGROUP_STAT_NSTATS];
> };
> @@ -4292,6 +4299,64 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp,
> return 0;
> }
>
> +static u64 mem_cgroup_dirty_read(struct cgroup *cgrp, struct cftype *cft)
> +{
> + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp);
> + bool root;
> +
> + root = mem_cgroup_is_root(mem);
> +
> + switch (cft->private) {
> + case MEM_CGROUP_DIRTY_RATIO:
> + return root ? vm_dirty_ratio : mem->dirty_param.dirty_ratio;
> + case MEM_CGROUP_DIRTY_BYTES:
> + return root ? vm_dirty_bytes : mem->dirty_param.dirty_bytes;
> + case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
> + return root ? dirty_background_ratio :
> + mem->dirty_param.dirty_background_ratio;
> + case MEM_CGROUP_DIRTY_BACKGROUND_BYTES:
> + return root ? dirty_background_bytes :
> + mem->dirty_param.dirty_background_bytes;
> + default:
> + BUG();
> + }
> +}
> +
> +static int
> +mem_cgroup_dirty_write(struct cgroup *cgrp, struct cftype *cft, u64 val)
> +{
> + struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
> + int type = cft->private;
> +
> + if (cgrp->parent == NULL)
> + return -EINVAL;
> + if ((type == MEM_CGROUP_DIRTY_RATIO ||
> + type == MEM_CGROUP_DIRTY_BACKGROUND_RATIO) && val > 100)
> + return -EINVAL;
> + switch (type) {
> + case MEM_CGROUP_DIRTY_RATIO:
> + memcg->dirty_param.dirty_ratio = val;
> + memcg->dirty_param.dirty_bytes = 0;
> + break;
> + case MEM_CGROUP_DIRTY_BYTES:
> + memcg->dirty_param.dirty_bytes = val;
> + memcg->dirty_param.dirty_ratio = 0;
> + break;
> + case MEM_CGROUP_DIRTY_BACKGROUND_RATIO:
> + memcg->dirty_param.dirty_background_ratio = val;
> + memcg->dirty_param.dirty_background_bytes = 0;
> + break;
> + case MEM_CGROUP_DIRTY_BACKGROUND_BYTES:
> + memcg->dirty_param.dirty_background_bytes = val;
> + memcg->dirty_param.dirty_background_ratio = 0;
> + break;


Curious....is this same behavior as vm_dirty_ratio ?


Thanks,
-Kame

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