Re: [PATCH v3 03/28] x86/sgx: Add 'struct sgx_epc_lru_lists' to encapsulate lru list(s)

Haitao Huang
2023-07-17T13:26:50Z

On Mon, 17 Jul 2023 07:45:36 -0500, Jarkko Sakkinen <jarkko@kernel.org>
wrote:

> On Wed Jul 12, 2023 at 11:01 PM UTC, Haitao Huang wrote:
>> From: Kristen Carlson Accardi <kristen@linux.intel.com>
>>
>> Introduce a data structure to wrap the existing reclaimable list
>> and its spinlock in a struct to minimize the code changes needed
>> to handle multiple LRUs as well as reclaimable and non-reclaimable
>> lists. The new structure will be used in a following set of patches to
>> implement SGX EPC cgroups.
>>
>> The changes to the structure needed for unreclaimable lists will be
>> added in later patches.
>>
>> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
>> Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
>> Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
>> Cc: Sean Christopherson <seanjc@google.com>
>>
>> V3:
>> Removed the helper functions and revised commit messages
>> ---
>> arch/x86/kernel/cpu/sgx/sgx.h | 17 +++++++++++++++++
>> 1 file changed, 17 insertions(+)
>>
>> diff --git a/arch/x86/kernel/cpu/sgx/sgx.h
>> b/arch/x86/kernel/cpu/sgx/sgx.h
>> index f6e3c5810eef..77fceba73a25 100644
>> --- a/arch/x86/kernel/cpu/sgx/sgx.h
>> +++ b/arch/x86/kernel/cpu/sgx/sgx.h
>> @@ -92,6 +92,23 @@ static inline void *sgx_get_epc_virt_addr(struct
>> sgx_epc_page *page)
>> return section->virt_addr + index * PAGE_SIZE;
>> }
>>
>> +/*
>> + * This data structure wraps a list of reclaimable EPC pages, and a
>> list of
>> + * non-reclaimable EPC pages and is used to implement a LRU policy
>> during
>> + * reclamation.
>> + */
>> +struct sgx_epc_lru_lists {
>> + /* Must acquire this lock to access */
>> + spinlock_t lock;
>
> Isn't this self-explanatory, why the inline comment?

I got a warning from the checkpatch script complaining this lock needs
comments.

Thanks
Haitao