Merge "Allow memory metrics on devices that use kernel LMK" (446014ec) · Commits · e / os / android_system_core

lmkd/lmkd.c

+75 −2

Original line number	Diff line number	Diff line
		@@ -189,8 +189,8 @@ static struct sock_event_handler_info data_sock[MAX_DATA_CONN];
		/* 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 @@ err_open_mpfd:
		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 @@ static int init(void) {

		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) &&