Allow memory metrics on devices that use kernel LMK
Bug: 130017100
Test: Tested manually
Change-Id: I37f6edb71decc1260bd521595842508926fa86aa
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 2de7378..48140b8 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -189,8 +189,8 @@
/* vmpressure event handler data */
static struct event_handler_info vmpressure_hinfo[VMPRESS_LEVEL_COUNT];
-/* 3 memory pressure levels, 1 ctrl listen socket, 2 ctrl data socket */
-#define MAX_EPOLL_EVENTS (1 + MAX_DATA_CONN + VMPRESS_LEVEL_COUNT)
+/* 3 memory pressure levels, 1 ctrl listen socket, 2 ctrl data socket, 1 lmk events */
+#define MAX_EPOLL_EVENTS (2 + MAX_DATA_CONN + VMPRESS_LEVEL_COUNT)
static int epollfd;
static int maxevents;
@@ -1863,6 +1863,74 @@
return false;
}
+#ifdef LMKD_LOG_STATS
+static int kernel_poll_fd = -1;
+
+static void poll_kernel() {
+ if (kernel_poll_fd == -1) {
+ // not waiting
+ return;
+ }
+
+ while (1) {
+ char rd_buf[256];
+ int bytes_read =
+ TEMP_FAILURE_RETRY(pread(kernel_poll_fd, (void*)rd_buf, sizeof(rd_buf), 0));
+ if (bytes_read <= 0) break;
+ rd_buf[bytes_read] = '\0';
+
+ int64_t pid;
+ int64_t uid;
+ int64_t group_leader_pid;
+ int64_t min_flt;
+ int64_t maj_flt;
+ int64_t rss_in_pages;
+ int16_t oom_score_adj;
+ int16_t min_score_adj;
+ int64_t starttime;
+ char* taskname = 0;
+ int fields_read = sscanf(rd_buf,
+ "%" SCNd64 " %" SCNd64 " %" SCNd64 " %" SCNd64 " %" SCNd64
+ " %" SCNd64 " %" SCNd16 " %" SCNd16 " %" SCNd64 "\n%m[^\n]",
+ &pid, &uid, &group_leader_pid, &min_flt, &maj_flt, &rss_in_pages,
+ &oom_score_adj, &min_score_adj, &starttime, &taskname);
+
+ /* only the death of the group leader process is logged */
+ if (fields_read == 10 && group_leader_pid == pid) {
+ int64_t process_start_time_ns = starttime * (NS_PER_SEC / sysconf(_SC_CLK_TCK));
+ stats_write_lmk_kill_occurred(log_ctx, LMK_KILL_OCCURRED, uid, taskname, oom_score_adj,
+ min_flt, maj_flt, rss_in_pages * PAGE_SIZE, 0, 0,
+ process_start_time_ns, min_score_adj);
+ }
+
+ free(taskname);
+ }
+}
+
+static struct event_handler_info kernel_poll_hinfo = {0, poll_kernel};
+
+static void init_poll_kernel() {
+ struct epoll_event epev;
+ kernel_poll_fd =
+ TEMP_FAILURE_RETRY(open("/proc/lowmemorykiller", O_RDONLY | O_NONBLOCK | O_CLOEXEC));
+
+ if (kernel_poll_fd < 0) {
+ ALOGE("kernel lmk event file could not be opened; errno=%d", kernel_poll_fd);
+ return;
+ }
+
+ epev.events = EPOLLIN;
+ epev.data.ptr = (void*)&kernel_poll_hinfo;
+ if (epoll_ctl(epollfd, EPOLL_CTL_ADD, kernel_poll_fd, &epev) != 0) {
+ ALOGE("epoll_ctl for lmk events failed; errno=%d", errno);
+ close(kernel_poll_fd);
+ kernel_poll_fd = -1;
+ } else {
+ maxevents++;
+ }
+}
+#endif
+
static int init(void) {
struct epoll_event epev;
int i;
@@ -1910,6 +1978,11 @@
if (use_inkernel_interface) {
ALOGI("Using in-kernel low memory killer interface");
+#ifdef LMKD_LOG_STATS
+ if (enable_stats_log) {
+ init_poll_kernel();
+ }
+#endif
} else {
/* Try to use psi monitor first if kernel has it */
use_psi_monitors = property_get_bool("ro.lmk.use_psi", true) &&