On 2024/7/2 15:24, Kamalesh Babulal wrote:
> 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.
Thanks for your review, will fix it.
>
>> + misc_cg_update_watermark(res, new_usage);
>> }
>> return 0;
>>
>
>
