From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Move the isolation loop into a helper, sgx_isolate_pages(), in
preparation for existence of multiple LRUs. Expose the helper to other
SGX code so that it can be called from the EPC cgroup code, e.g., to
isolate pages from a single cgroup LRU. Exposing the isolation loop
allows the cgroup iteration logic to be wholly encapsulated within the
cgroup code.
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx>
Signed-off-by: Haitao Huang <haitao.huang@xxxxxxxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
---
V4:
- No changes other than reordering the patches
---
arch/x86/kernel/cpu/sgx/main.c | 57 +++++++++++++++++++++-------------
arch/x86/kernel/cpu/sgx/sgx.h | 2 ++
2 files changed, 37 insertions(+), 22 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index e1dde431a400..ce316bd5e5bb 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -283,6 +283,40 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page,
mutex_unlock(&encl->lock);
}
+/**
+ * sgx_isolate_epc_pages() - Isolate pages from an LRU for reclaim
+ * @lru: LRU from which to reclaim
+ * @nr_to_scan: Number of pages to scan for reclaim
+ * @dst: Destination list to hold the isolated pages
+ */
+void sgx_isolate_epc_pages(struct sgx_epc_lru_lists *lru, size_t nr_to_scan,
+ struct list_head *dst)
+{
+ struct sgx_encl_page *encl_page;
+ struct sgx_epc_page *epc_page;
+
+ spin_lock(&lru->lock);
+ for (; nr_to_scan > 0; --nr_to_scan) {
+ epc_page = list_first_entry_or_null(&lru->reclaimable, struct sgx_epc_page, list);
+ if (!epc_page)
+ break;
+
+ encl_page = epc_page->encl_page;
+
+ if (kref_get_unless_zero(&encl_page->encl->refcount)) {
+ sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIM_IN_PROGRESS);
+ list_move_tail(&epc_page->list, dst);
+ } else {
+ /* The owner is freeing the page, remove it from the
+ * LRU list
+ */
+ sgx_epc_page_reset_state(epc_page);
+ list_del_init(&epc_page->list);
+ }
+ }
+ spin_unlock(&lru->lock);
+}
+
/**
* sgx_reclaim_epc_pages() - Reclaim EPC pages from the consumers
* @nr_to_scan: Number of EPC pages to scan for reclaim
@@ -310,28 +344,7 @@ size_t sgx_reclaim_epc_pages(size_t nr_to_scan, bool ignore_age)
size_t ret;
size_t i;
- spin_lock(&sgx_global_lru.lock);
- for (i = 0; i < SGX_NR_TO_SCAN; i++) {
- epc_page = list_first_entry_or_null(&sgx_global_lru.reclaimable,
- struct sgx_epc_page, list);
- if (!epc_page)
- break;
-
- list_del_init(&epc_page->list);
- encl_page = epc_page->encl_page;
-
- if (kref_get_unless_zero(&encl_page->encl->refcount) != 0) {
- sgx_epc_page_set_state(epc_page, SGX_EPC_PAGE_RECLAIM_IN_PROGRESS);
- list_move_tail(&epc_page->list, &iso);
- } else {
- /* The owner is freeing the page, remove it from the
- * LRU list
- */
- sgx_epc_page_reset_state(epc_page);
- list_del_init(&epc_page->list);
- }
- }
- spin_unlock(&sgx_global_lru.lock);
+ sgx_isolate_epc_pages(&sgx_global_lru, nr_to_scan, &iso);
if (list_empty(&iso))
return 0;
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index aa4ec2c0ce96..7e21192b87a8 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -178,6 +178,8 @@ int sgx_drop_epc_page(struct sgx_epc_page *page);
struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim);
bool sgx_epc_oom(struct sgx_epc_lru_lists *lrus);
size_t sgx_reclaim_epc_pages(size_t nr_to_scan, bool ignore_age);
+void sgx_isolate_epc_pages(struct sgx_epc_lru_lists *lrus, size_t nr_to_scan,
+ struct list_head *dst);
void sgx_ipi_cb(void *info);
--
2.25.1
