On Tue, Nov 26, 2019 at 08:56:00PM +0100, Giuseppe Scrivano wrote:
> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
> index 2ac38bdc18a1..5a6b381e9b92 100644
> --- a/mm/hugetlb_cgroup.c
> +++ b/mm/hugetlb_cgroup.c
> @@ -283,10 +283,55 @@ static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
> }
> }
>
> +static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v)
> +{
> + int idx;
> + u64 val;
> + bool write_raw = false;
> + struct cftype *cft = seq_cft(seq);
> + unsigned long limit;
> + struct page_counter *counter;
> + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(seq_css(seq));
> +
> + idx = MEMFILE_IDX(cft->private);
> + counter = &h_cg->hugepage[idx];
> +
> + switch (MEMFILE_ATTR(cft->private)) {
> + case RES_USAGE:
> + val = (u64)page_counter_read(counter);
> + break;
> + case RES_LIMIT:
> + val = (u64)counter->max;
> + break;
> + case RES_MAX_USAGE:
> + val = (u64)counter->watermark;
> + break;
This case is dead code now.
> + case RES_FAILCNT:
> + val = counter->failcnt;
> + write_raw = true;
> + break;
> + default:
> + BUG();
> + }
> +
> + limit = round_down(PAGE_COUNTER_MAX,
> + 1 << huge_page_order(&hstates[idx]));
> +
> + if (val == limit && !write_raw)
> + seq_puts(seq, "max\n");
This branch applies (or should apply!) only to RES_LIMIT, never
RES_USAGE or RES_FAILCNT.
> + else if (write_raw)
> + seq_printf(seq, "%llu\n", val);
This applies only to RES_FAILCNT
> + else
> + seq_printf(seq, "%llu\n", val * PAGE_SIZE);
And this applies to RES_USAGE and RES_LIMIT.
But this seems unnecessarily obscure. Can you just put the
seq_printf()s directly into the case statements?
