lmkd: Change procfs read routine to handle files larger than 1 page in size am: a77b327bb9 (36c9c52f) · Commits · e / os / android_system_core

lmkd/lmkd.c

+52 −18

Original line number	Diff line number	Diff line
		@@ -424,28 +424,50 @@ static ssize_t read_all(int fd, char *buf, size_t max_len)
		* memory pressure to minimize file opening which by itself requires kernel
		* memory allocation and might result in a stall on memory stressed system.
		*/
		static int reread_file(struct reread_data data, char buf, size_t buf_size) {
		static char reread_file(struct reread_data data) {
		/* start with page-size buffer and increase if needed */
		static ssize_t buf_size = PAGE_SIZE;
		static char new_buf, buf = NULL;
		ssize_t size;

		if (data->fd == -1) {
		data->fd = open(data->filename, O_RDONLY \| O_CLOEXEC);
		if (data->fd == -1) {
		/* First-time buffer initialization */
		if (!buf && (buf = malloc(buf_size)) == NULL) {
		return NULL;
		}

		data->fd = TEMP_FAILURE_RETRY(open(data->filename, O_RDONLY \| O_CLOEXEC));
		if (data->fd < 0) {
		ALOGE("%s open: %s", data->filename, strerror(errno));
		return -1;
		return NULL;
		}
		}

		while (true) {
		size = read_all(data->fd, buf, buf_size - 1);
		if (size < 0) {
		ALOGE("%s read: %s", data->filename, strerror(errno));
		close(data->fd);
		data->fd = -1;
		return -1;
		return NULL;
		}
		if (size < buf_size - 1) {
		break;
		}
		/*
		* Since we are reading /proc files we can't use fstat to find out
		* the real size of the file. Double the buffer size and keep retrying.
		*/
		if ((new_buf = realloc(buf, buf_size * 2)) == NULL) {
		errno = ENOMEM;
		return NULL;
		}
		buf = new_buf;
		buf_size *= 2;
		}
		ALOG_ASSERT((size_t)size < buf_size - 1, "%s too large", data->filename);
		buf[size] = 0;

		return 0;
		return buf;
		}

		static struct proc *pid_lookup(int pid) {
		@@ -1200,13 +1222,13 @@ static int zoneinfo_parse(union zoneinfo *zi) {
		.filename = ZONEINFO_PATH,
		.fd = -1,
		};
		char buf[PAGE_SIZE];
		char *buf;
		char *save_ptr;
		char *line;

		memset(zi, 0, sizeof(union zoneinfo));

		if (reread_file(&file_data, buf, sizeof(buf)) < 0) {
		if ((buf = reread_file(&file_data)) == NULL) {
		return -1;
		}

		@@ -1254,13 +1276,13 @@ static int meminfo_parse(union meminfo *mi) {
		.filename = MEMINFO_PATH,
		.fd = -1,
		};
		char buf[PAGE_SIZE];
		char *buf;
		char *save_ptr;
		char *line;

		memset(mi, 0, sizeof(union meminfo));

		if (reread_file(&file_data, buf, sizeof(buf)) < 0) {
		if ((buf = reread_file(&file_data)) == NULL) {
		return -1;
		}

		@@ -1542,9 +1564,9 @@ static int find_and_kill_process(int min_score_adj) {
		static int64_t get_memory_usage(struct reread_data *file_data) {
		int ret;
		int64_t mem_usage;
		char buf[32];
		char *buf;

		if (reread_file(file_data, buf, sizeof(buf)) < 0) {
		if ((buf = reread_file(file_data)) == NULL) {
		return -1;
		}

		@@ -2014,6 +2036,10 @@ static void init_poll_kernel() {
		#endif

		static int init(void) {
		struct reread_data file_data = {
		.filename = ZONEINFO_PATH,
		.fd = -1,
		};
		struct epoll_event epev;
		int i;
		int ret;
		@@ -2091,6 +2117,14 @@ static int init(void) {

		memset(killcnt_idx, KILLCNT_INVALID_IDX, sizeof(killcnt_idx));

		/*
		* Read zoneinfo as the biggest file we read to create and size the initial
		* read buffer and avoid memory re-allocations during memory pressure
		*/
		if (reread_file(&file_data) == NULL) {
		ALOGE("Failed to read %s: %s", file_data.filename, strerror(errno));
		}

		return 0;
		}