[PATCH v3 11/28] x85/sgx: Return the number of EPC pages that were successfully reclaimed

Haitao Huang
2023-07-12T23:03:17Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

Return the number of reclaimed pages from sgx_reclaim_pages(), the EPC
cgroup will use the result to track the success rate of its reclaim
calls, e.g. to escalate to a more forceful reclaiming mode if necessary.

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>
---
arch/x86/kernel/cpu/sgx/main.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index cd5e5517866a..4fc931156972 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -299,15 +299,15 @@ static void sgx_reclaimer_write(struct sgx_epc_page *epc_page,
* problematic as it would increase the lock contention too much, which would
* halt forward progress.
*/
-static void sgx_reclaim_pages(int nr_to_scan)
+static size_t sgx_reclaim_pages(size_t nr_to_scan)
{
struct sgx_backing backing[SGX_NR_TO_SCAN_MAX];
struct sgx_epc_page *epc_page, *tmp;
struct sgx_encl_page *encl_page;
pgoff_t page_index;
LIST_HEAD(iso);
- int ret;
- int i;
+ size_t ret;
+ size_t i;

spin_lock(&sgx_global_lru.lock);
for (i = 0; i < SGX_NR_TO_SCAN; i++) {
@@ -333,7 +333,7 @@ static void sgx_reclaim_pages(int nr_to_scan)
spin_unlock(&sgx_global_lru.lock);

if (list_empty(&iso))
- return;
+ return 0;

i = 0;
list_for_each_entry_safe(epc_page, tmp, &iso, list) {
@@ -378,6 +378,7 @@ static void sgx_reclaim_pages(int nr_to_scan)

sgx_free_epc_page(epc_page);
}
+ return i;
}

static bool sgx_should_reclaim(unsigned long watermark)
--
2.25.1