diff mbox series

[v3,04/28] x86/sgx: Use sgx_epc_lru_lists for existing active page list

Message ID 20230712230202.47929-5-haitao.huang@linux.intel.com
State New
Headers
Series Add Cgroup support for SGX EPC memory |

Commit Message

Haitao Huang July 12, 2023, 11:01 p.m. UTC 
  From: Kristen Carlson Accardi <kristen@linux.intel.com>

Replace the existing sgx_active_page_list and its spinlock with
a global sgx_epc_lru_lists struct.

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:
- Remove usage of list wrapper
---
 arch/x86/kernel/cpu/sgx/main.c | 39 +++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 19 deletions(-)

Comments

Jarkko Sakkinen July 17, 2023, 12:47 p.m. UTC | #1 
On Wed Jul 12, 2023 at 11:01 PM UTC, Haitao Huang wrote:
> From: Kristen Carlson Accardi <kristen@linux.intel.com>
>
> Replace the existing sgx_active_page_list and its spinlock with
> a global sgx_epc_lru_lists struct.

Similarly as the previous patch, I would extend this story a tiny
bit forward to see the connection with the follow-up patches.

BR, Jarkko
Haitao Huang July 31, 2023, 8:43 p.m. UTC | #2 
On Mon, 17 Jul 2023 07:47:01 -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>
>>
>> Replace the existing sgx_active_page_list and its spinlock with
>> a global sgx_epc_lru_lists struct.
>
> Similarly as the previous patch, I would extend this story a tiny
> bit forward to see the connection with the follow-up patches.
>
Sure

I also feel it may flow better by moving all changes related to  
'unreclaimable' such as owner field for VA, flags for types of owners,  
storing unreclaimables to LRU, etc. to later after all changes dealing  
with reclaimables are introduced. The unreclaimables are only of concern  
when OOM is involved so it'd be better to do them right before OOM.

Thanks
Haitao
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 39939b7496b0..71c3386ccf23 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -26,10 +26,9 @@  static DEFINE_XARRAY(sgx_epc_address_space);
 
 /*
  * These variables are part of the state of the reclaimer, and must be accessed
- * with sgx_reclaimer_lock acquired.
+ * with sgx_global_lru.lock acquired.
  */
-static LIST_HEAD(sgx_active_page_list);
-static DEFINE_SPINLOCK(sgx_reclaimer_lock);
+static struct sgx_epc_lru_lists sgx_global_lru;
 
 static atomic_long_t sgx_nr_free_pages = ATOMIC_LONG_INIT(0);
 
@@ -304,13 +303,13 @@  static void sgx_reclaim_pages(void)
 	int ret;
 	int i;
 
-	spin_lock(&sgx_reclaimer_lock);
+	spin_lock(&sgx_global_lru.lock);
 	for (i = 0; i < SGX_NR_TO_SCAN; i++) {
-		if (list_empty(&sgx_active_page_list))
+		epc_page = list_first_entry_or_null(&sgx_global_lru.reclaimable,
+						    struct sgx_epc_page, list);
+		if (!epc_page)
 			break;
 
-		epc_page = list_first_entry(&sgx_active_page_list,
-					    struct sgx_epc_page, list);
 		list_del_init(&epc_page->list);
 		encl_page = epc_page->encl_page;
 
@@ -322,7 +321,7 @@  static void sgx_reclaim_pages(void)
 			 */
 			epc_page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED;
 	}
-	spin_unlock(&sgx_reclaimer_lock);
+	spin_unlock(&sgx_global_lru.lock);
 
 	for (i = 0; i < cnt; i++) {
 		epc_page = chunk[i];
@@ -345,9 +344,9 @@  static void sgx_reclaim_pages(void)
 		continue;
 
 skip:
-		spin_lock(&sgx_reclaimer_lock);
-		list_add_tail(&epc_page->list, &sgx_active_page_list);
-		spin_unlock(&sgx_reclaimer_lock);
+		spin_lock(&sgx_global_lru.lock);
+		list_add_tail(&epc_page->list, &sgx_global_lru.reclaimable);
+		spin_unlock(&sgx_global_lru.lock);
 
 		kref_put(&encl_page->encl->refcount, sgx_encl_release);
 
@@ -378,7 +377,7 @@  static void sgx_reclaim_pages(void)
 static bool sgx_should_reclaim(unsigned long watermark)
 {
 	return atomic_long_read(&sgx_nr_free_pages) < watermark &&
-	       !list_empty(&sgx_active_page_list);
+	       !list_empty(&sgx_global_lru.reclaimable);
 }
 
 /*
@@ -430,6 +429,8 @@  static bool __init sgx_page_reclaimer_init(void)
 
 	ksgxd_tsk = tsk;
 
+	sgx_lru_init(&sgx_global_lru);
+
 	return true;
 }
 
@@ -505,10 +506,10 @@  struct sgx_epc_page *__sgx_alloc_epc_page(void)
  */
 void sgx_mark_page_reclaimable(struct sgx_epc_page *page)
 {
-	spin_lock(&sgx_reclaimer_lock);
+	spin_lock(&sgx_global_lru.lock);
 	page->flags |= SGX_EPC_PAGE_RECLAIMER_TRACKED;
-	list_add_tail(&page->list, &sgx_active_page_list);
-	spin_unlock(&sgx_reclaimer_lock);
+	list_add_tail(&page->list, &sgx_global_lru.reclaimable);
+	spin_unlock(&sgx_global_lru.lock);
 }
 
 /**
@@ -523,18 +524,18 @@  void sgx_mark_page_reclaimable(struct sgx_epc_page *page)
  */
 int sgx_unmark_page_reclaimable(struct sgx_epc_page *page)
 {
-	spin_lock(&sgx_reclaimer_lock);
+	spin_lock(&sgx_global_lru.lock);
 	if (page->flags & SGX_EPC_PAGE_RECLAIMER_TRACKED) {
 		/* The page is being reclaimed. */
 		if (list_empty(&page->list)) {
-			spin_unlock(&sgx_reclaimer_lock);
+			spin_unlock(&sgx_global_lru.lock);
 			return -EBUSY;
 		}
 
 		list_del(&page->list);
 		page->flags &= ~SGX_EPC_PAGE_RECLAIMER_TRACKED;
 	}
-	spin_unlock(&sgx_reclaimer_lock);
+	spin_unlock(&sgx_global_lru.lock);
 
 	return 0;
 }
@@ -567,7 +568,7 @@  struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim)
 			break;
 		}
 
-		if (list_empty(&sgx_active_page_list))
+		if (list_empty(&sgx_global_lru.reclaimable))
 			return ERR_PTR(-ENOMEM);
 
 		if (!reclaim) {