Hi Tim,
On Fri, 02 Feb 2024 17:45:05 -0600, Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
wrote:
On Mon, 2024-01-22 at 09:20 -0800, Haitao Huang wrote:
@@ -1047,29 +1037,38 @@ static struct mem_cgroup
*sgx_encl_get_mem_cgroup(struct sgx_encl *encl)
* @encl: an enclave pointer
* @page_index: enclave page index
* @backing: data for accessing backing storage for the page
+ * @indirect: in ksgxd or EPC cgroup work queue context
+ *
+ * Create a backing page for loading data back into an EPC page with
ELDU. This function takes
+ * a reference on a new backing page which must be dropped with a
corresponding call to
+ * sgx_encl_put_backing().
*
- * When called from ksgxd, sets the active memcg from one of the
- * mms in the enclave's mm_list prior to any backing page allocation,
- * in order to ensure that shmem page allocations are charged to the
- * enclave. Create a backing page for loading data back into an EPC
page with
- * ELDU. This function takes a reference on a new backing page which
- * must be dropped with a corresponding call to sgx_encl_put_backing().
+ * When @indirect is true, sets the active memcg from one of the mms
in the enclave's mm_list
+ * prior to any backing page allocation, in order to ensure that shmem
page allocations are
+ * charged to the enclave.
*
* Return:
* 0 on success,
* -errno otherwise.
*/
int sgx_encl_alloc_backing(struct sgx_encl *encl, unsigned long
page_index,
- struct sgx_backing *backing)
+ struct sgx_backing *backing, bool indirect)
{
- struct mem_cgroup *encl_memcg = sgx_encl_get_mem_cgroup(encl);
- struct mem_cgroup *memcg = set_active_memcg(encl_memcg);
+ struct mem_cgroup *encl_memcg;
+ struct mem_cgroup *memcg;
int ret;
+ if (indirect) {
+ encl_memcg = sgx_encl_get_mem_cgroup(encl);
+ memcg = set_active_memcg(encl_memcg);
+ }
+
ret = __sgx_encl_get_backing(encl, page_index, backing);
- set_active_memcg(memcg);
- mem_cgroup_put(encl_memcg);
+ if (indirect) {
+ set_active_memcg(memcg);
+ mem_cgroup_put(encl_memcg);
+ }
You can reduce the number of if statements to make the logic
simpler. Something like
if (!indirect)
return __sgx_encl_get_backing(encl, page_index, backing);
encl_memcg = sgx_encl_get_mem_cgroup(encl);
memcg = set_active_memcg(encl_memcg);
ret = __sgx_encl_get_backing(encl, page_index, backing);
set_active_memcg(memcg);
mem_cgroup_put(encl_memcg);
return ret;
Tim
Yes, will do.
Thanks
Haitao
