Hi,
On 7/2/24 6:18 AM, Xiu Jianfeng wrote:
[...]
> diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
> index 79a3717a5803..7f5180a8f461 100644
> --- a/kernel/cgroup/misc.c
> +++ b/kernel/cgroup/misc.c
> @@ -121,6 +121,17 @@ static void misc_cg_cancel_charge(enum misc_res_type type, struct misc_cg *cg,
> misc_res_name[type]);
> }
>
> +static void misc_cg_update_watermark(struct misc_res *res, u64 new_usage)
> +{
> + u64 old;
> +
> + do {
> + old = READ_ONCE(res->watermark);
> + if (cmpxchg(&res->watermark, old, new_usage) == old)
> + break;
> + } while (1);
> +}
> +
> /**
> * misc_cg_try_charge() - Try charging the misc cgroup.
> * @type: Misc res type to charge.
> @@ -159,6 +170,7 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount)
> ret = -EBUSY;
> goto err_charge;
> }
you may need to re-introduce the check:
if (new_usage > READ_ONCE(res->watermark))
without it, the res->watermark will be updated unconditionally.
> + misc_cg_update_watermark(res, new_usage);
> }
> return 0;
>
--
Thanks,
Kamalesh
