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To:     =?iso-8859-15?Q?Michal_Koutn=FD?= <mkoutny@suse.com>
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Subject: Re: [PATCH v5 16/18] x86/sgx: Limit process EPC usage with misc
 cgroup controller
References: <20230923030657.16148-1-haitao.huang@linux.intel.com>
 <20230923030657.16148-17-haitao.huang@linux.intel.com>
 <mc3js6ye7sw2z4gyppqwld7lepke5swqlfbx4mchqwxbwgwts3@c5vzusgelgyc>
Date:   Thu, 19 Oct 2023 11:05:18 -0500
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From:   "Haitao Huang" <haitao.huang@linux.intel.com>
Organization: Intel
Message-ID: <op.2c2ka4kwwjvjmi@hhuan26-mobl.amr.corp.intel.com>
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On Tue, 17 Oct 2023 13:54:54 -0500, Michal Koutn=FD <mkoutny@suse.com> w=
rote:

> On Fri, Sep 22, 2023 at 08:06:55PM -0700, Haitao Huang  =

> <haitao.huang@linux.intel.com> wrote:
>> +static void sgx_epc_cgroup_free(struct misc_cg *cg)
>> +{
>> +	struct sgx_epc_cgroup *epc_cg;
>> +
>> +	epc_cg =3D sgx_epc_cgroup_from_misc_cg(cg);
>
> It should check for !epc_cg since the misc controller implementation
> in misc_cg_alloc() would roll back even on non-allocated resources.

Good catch. Will fix.

>
>> +	cancel_work_sync(&epc_cg->reclaim_work);
>> +	kfree(epc_cg);
>> +}
>> +
>> +static void sgx_epc_cgroup_max_write(struct misc_cg *cg)
>> +{
>> +	struct sgx_epc_reclaim_control rc;
>> +	struct sgx_epc_cgroup *epc_cg;
>> +
>> +	epc_cg =3D sgx_epc_cgroup_from_misc_cg(cg);
>> +
>> +	sgx_epc_reclaim_control_init(&rc, epc_cg);
>> +	/* Let the reclaimer to do the work so user is not blocked */
>> +	queue_work(sgx_epc_cg_wq, &rc.epc_cg->reclaim_work);
>
> This is weird. The writer will never learn about the result of the
> operation.
>
Right. With the new plan, this callback will be removed.

Thanks
Haitao