[lxc-devel] [lxcfs/master] loadavg

zhang2639 on Github lxc-bot at linuxcontainers.org
Wed May 2 12:40:45 UTC 2018


A non-text attachment was scrubbed...
Name: not available
Type: text/x-mailbox
Size: 1377 bytes
Desc: not available
URL: <http://lists.linuxcontainers.org/pipermail/lxc-devel/attachments/20180502/15aade6e/attachment.bin>
-------------- next part --------------
From ba5ab95335f6d0c7df843b57dbc88089765bed97 Mon Sep 17 00:00:00 2001
From: zhang2639 <zhangshiqiang at hust.edu.cn>
Date: Wed, 18 Apr 2018 19:22:40 +0800
Subject: [PATCH 1/4] Necessary Instructions For Loadavg

Signed-off-by: zhang2639 <zhangshiqiang at hust.edu.cn>
Signed-off-by: yuwang <yuwang at linux.alibaba.com>
---
 bindings.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/bindings.c b/bindings.c
index 9657160..7e82fb9 100644
--- a/bindings.c
+++ b/bindings.c
@@ -66,6 +66,7 @@ enum {
 	LXC_TYPE_PROC_STAT,
 	LXC_TYPE_PROC_DISKSTATS,
 	LXC_TYPE_PROC_SWAPS,
+	LXC_TYPE_PROC_LOADAVG,
 };
 
 struct file_info {
@@ -4128,7 +4129,8 @@ int proc_getattr(const char *path, struct stat *sb)
 			strcmp(path, "/proc/uptime") == 0 ||
 			strcmp(path, "/proc/stat") == 0 ||
 			strcmp(path, "/proc/diskstats") == 0 ||
-			strcmp(path, "/proc/swaps") == 0) {
+			strcmp(path, "/proc/swaps") == 0 ||
+			strcmp(path, "/proc/loadavg") == 0) {
 		sb->st_size = 0;
 		sb->st_mode = S_IFREG | 00444;
 		sb->st_nlink = 1;
@@ -4148,7 +4150,8 @@ int proc_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offs
 	    filler(buf, "stat", NULL, 0) != 0 ||
 	    filler(buf, "uptime", NULL, 0) != 0 ||
 	    filler(buf, "diskstats", NULL, 0) != 0 ||
-	    filler(buf, "swaps", NULL, 0) != 0)
+	    filler(buf, "swaps", NULL, 0) != 0   ||
+	    filler(buf, "loadavg", NULL, 0) != 0)
 		return -EINVAL;
 	return 0;
 }
@@ -4170,6 +4173,8 @@ int proc_open(const char *path, struct fuse_file_info *fi)
 		type = LXC_TYPE_PROC_DISKSTATS;
 	else if (strcmp(path, "/proc/swaps") == 0)
 		type = LXC_TYPE_PROC_SWAPS;
+	else if (strcmp(path, "/proc/loadavg") == 0)
+		type = LXC_TYPE_PROC_LOADAVG;
 	if (type == -1)
 		return -ENOENT;
 
@@ -4227,6 +4232,8 @@ int proc_read(const char *path, char *buf, size_t size, off_t offset,
 		return proc_diskstats_read(buf, size, offset, fi);
 	case LXC_TYPE_PROC_SWAPS:
 		return proc_swaps_read(buf, size, offset, fi);
+	case LXC_TYPE_PROC_LOADAVG:
+		return proc_loadavg_read(buf, size, offset, fi);
 	default:
 		return -EINVAL;
 	}

From 11c62f5738db64f915e5b85a129e1ca396be24bd Mon Sep 17 00:00:00 2001
From: zhang2639 <zhangshiqiang at hust.edu.cn>
Date: Wed, 2 May 2018 20:02:37 +0800
Subject: [PATCH 2/4] Use hash table to store load information

struct load_head{} contains three locks for thread synchronization
and a pointer to the hash list.
struct load_node{} contains special information of container and
pointers to the hash node.
static struct load_head load_hash[LOAD_SIZE] is hash table.
calc_hash : get the hash of a special container.
init_load : initialize hash table.
insert_node : insert a container node to the hash table.
locate_node : find the specital container node.
del_node : delete a specital container node and return the next node
of it.

Signed-off-by: zhang2639 <zhangshiqiang at hust.edu.cn>
Signed-off-by: yuwang <yuwang at linux.alibaba.com>
---
 bindings.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 151 insertions(+)

diff --git a/bindings.c b/bindings.c
index 7e82fb9..489c355 100644
--- a/bindings.c
+++ b/bindings.c
@@ -80,6 +80,157 @@ struct file_info {
 	int cached;
 };
 
+/* The function of hash table.*/
+#define LOAD_SIZE 100 /*the size of hash_table */
+static int calc_hash(char *name)
+{
+	unsigned int hash = 0;
+	unsigned int x = 0;
+	/* ELFHash algorithm. */
+	while (*name) {
+		hash = (hash << 4) + *name++;
+		x = hash & 0xf0000000;
+		if (x != 0)
+			hash ^= (x >> 24);
+		hash &= ~x;
+	}
+	return ((hash & 0x7fffffff) % LOAD_SIZE);
+}
+
+struct load_node {
+	char *cg;  /*cg */
+	unsigned long avenrun[3];		/* Load averages */
+	unsigned int run_pid;
+	unsigned int total_pid;
+	unsigned int last_pid;
+	int cfd; /* The file descriptor of the mounted cgroup */
+	struct  load_node *next;
+	struct  load_node **pre;
+};
+
+struct load_head {
+	/*
+	 * The lock is about insert load_node and refresh load_node.To the first
+	 * load_node of each hash bucket, insert andrefresh in this hash bucket is
+	 * mutually exclusive.
+	 */
+	pthread_mutex_t lock;
+	/*
+	 * The rdlock is about read loadavg and delete load_node.To each hash
+	 * bucket, read and delete is mutually exclusive. But at the same time, we
+	 * allow paratactic read operation. This rdlock is at list level.
+	 */
+	pthread_rwlock_t rdlock;
+	/*
+	 * The rilock is about read loadavg and insert load_node.To the first
+	 * load_node of each hash bucket, read and insert is mutually exclusive.
+	 * But at the same time, we allow paratactic read operation.
+	 */
+	pthread_rwlock_t rilock;
+	struct load_node *next;
+};
+
+static struct load_head load_hash[LOAD_SIZE]; /* hash table */
+/*
+ * init_load initialize the hash table.
+ * Return 0 on success, return -1 on failure.
+ */
+static int init_load(void)
+{
+	int i;
+	int ret;
+
+	for (i = 0; i < LOAD_SIZE; i++) {
+		load_hash[i].next = NULL;
+		ret = pthread_mutex_init(&load_hash[i].lock, NULL);
+		if (ret != 0) {
+			lxcfs_error("%s\n", "Failed to initialize lock");
+			goto out3;
+		}
+		ret = pthread_rwlock_init(&load_hash[i].rdlock, NULL);
+		if (ret != 0) {
+			lxcfs_error("%s\n", "Failed to initialize rdlock");
+			goto out2;
+		}
+		ret = pthread_rwlock_init(&load_hash[i].rilock, NULL);
+		if (ret != 0) {
+			lxcfs_error("%s\n", "Failed to initialize rilock");
+			goto out1;
+		}
+	}
+	return 0;
+out1:
+	pthread_rwlock_destroy(&load_hash[i].rdlock);
+out2:
+	pthread_mutex_destroy(&load_hash[i].lock);
+out3:
+	while (i > 0) {
+		i--;
+		pthread_mutex_destroy(&load_hash[i].lock);
+		pthread_rwlock_destroy(&load_hash[i].rdlock);
+		pthread_rwlock_destroy(&load_hash[i].rilock);
+	}
+	return -1;
+}
+
+static void insert_node(struct load_node **n, int locate)
+{
+	struct load_node *f;
+
+	pthread_mutex_lock(&load_hash[locate].lock);
+	pthread_rwlock_wrlock(&load_hash[locate].rilock);
+	f = load_hash[locate].next;
+	load_hash[locate].next = *n;
+
+	(*n)->pre = &(load_hash[locate].next);
+	if (f)
+		f->pre = &((*n)->next);
+	(*n)->next = f;
+	pthread_mutex_unlock(&load_hash[locate].lock);
+	pthread_rwlock_unlock(&load_hash[locate].rilock);
+}
+/*
+ * locate_node() finds special node. Not return NULL means success.
+ * It should be noted that rdlock isn't unlocked at the end of code
+ * because this function is used to read special node. Delete is not
+ * allowed before read has ended.
+ * unlock rdlock only in proc_loadavg_read().
+ */
+static struct load_node *locate_node(char *cg, int locate)
+{
+	struct load_node *f = NULL;
+	int i = 0;
+
+	pthread_rwlock_rdlock(&load_hash[locate].rilock);
+	pthread_rwlock_rdlock(&load_hash[locate].rdlock);
+	if (load_hash[locate].next == NULL) {
+		pthread_rwlock_unlock(&load_hash[locate].rilock);
+		return f;
+	}
+	f = load_hash[locate].next;
+	pthread_rwlock_unlock(&load_hash[locate].rilock);
+	while (f && ((i = strcmp(f->cg, cg)) != 0))
+		f = f->next;
+	return f;
+}
+/* Delete the load_node n and return the next node of it. */
+static struct load_node *del_node(struct load_node *n, int locate)
+{
+	struct load_node *g;
+
+	pthread_rwlock_wrlock(&load_hash[locate].rdlock);
+	if (n->next == NULL) {
+		*(n->pre) = NULL;
+	} else {
+		*(n->pre) = n->next;
+		n->next->pre = n->pre;
+	}
+	g = n->next;
+	free(n->cg);
+	free(n);
+	pthread_rwlock_unlock(&load_hash[locate].rdlock);
+	return g;
+}
 /* Reserve buffer size to account for file size changes. */
 #define BUF_RESERVE_SIZE 512
 

From af54f8651bcab312c2a119d47ae43da3793b59ce Mon Sep 17 00:00:00 2001
From: zhang2639 <zhangshiqiang at hust.edu.cn>
Date: Wed, 2 May 2018 20:11:29 +0800
Subject: [PATCH 3/4] Calculate the average load and read them.

Use load daemon to calculate the average load and use proc_loadavg_read() to
read loadavg
calc_pid : find the process pid from cgroup path of a container.
calc_load : calculate the loadavg of a container.
refresh_load : refresh the loadavg of a container.
load_begin : traverse the hash table and update it.

Signed-off-by: zhang2639 <zhangshiqiang at hust.edu.cn>
Signed-off-by: yuwang <yuwang at linux.alibaba.com>
---
 bindings.c | 373 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 bindings.h |   1 +
 lxcfs.c    |  24 +++-
 3 files changed, 397 insertions(+), 1 deletion(-)

diff --git a/bindings.c b/bindings.c
index 489c355..edab10e 100644
--- a/bindings.c
+++ b/bindings.c
@@ -82,6 +82,22 @@ struct file_info {
 
 /* The function of hash table.*/
 #define LOAD_SIZE 100 /*the size of hash_table */
+#define FLUSH_TIME 5  /*the flush rate */
+#define DEPTH_DIR 3   /*the depth of per cgroup */
+/* The function of calculate loadavg .*/
+#define FSHIFT		11		/* nr of bits of precision */
+#define FIXED_1		(1<<FSHIFT)	/* 1.0 as fixed-point */
+#define EXP_1		1884		/* 1/exp(5sec/1min) as fixed-point */
+#define EXP_5		2014		/* 1/exp(5sec/5min) */
+#define EXP_15		2037		/* 1/exp(5sec/15min) */
+#define LOAD_INT(x) ((x) >> FSHIFT)
+#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
+/* 
+ * This parameter is used for proc_loadavg_read().
+ * 1 means use loadavg, 0 means not use.
+ */
+static int loadavg = 0;
+
 static int calc_hash(char *name)
 {
 	unsigned int hash = 0;
@@ -4244,6 +4260,363 @@ static int proc_swaps_read(char *buf, size_t size, off_t offset,
 	return rv;
 }
 
+/*
+ * Find the process pid from cgroup path.
+ * eg:from /sys/fs/cgroup/cpu/docker/containerid/cgroup.procs to find the process pid.
+ * @pid_buf : put pid to pid_buf.
+ * @dpath : the path of cgroup. eg: /docker/containerid or /docker/containerid/child-cgroup ...
+ * @depth : the depth of cgroup in container.
+ * @sum : return the number of pid.
+ * @cfd : the file descriptor of the mounted cgroup. eg: /sys/fs/cgroup/cpu
+ */
+static int calc_pid(char ***pid_buf, char *dpath, int depth, int sum, int cfd)
+{
+	DIR *dir;
+	int fd;
+	struct dirent *file;
+	FILE *f = NULL;
+	size_t linelen = 0;
+	char *line = NULL;
+	int pd;
+	char *path_dir, *path;
+	char **pid;
+
+	/* path = dpath + "/cgroup.procs" + /0 */
+	path = (char *)malloc(strlen(dpath) + 20);
+	if (!path) {
+		lxcfs_error("Failed to malloc %s in calc_pid!\n", dpath);
+		return sum;
+	}
+
+	strcpy(path, dpath);
+	fd = openat(cfd, path, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	dir = fdopendir(fd);
+	if (dir == NULL)
+		goto out;
+
+	while (((file = readdir(dir)) != NULL) && depth > 0) {
+		if (strncmp(file->d_name, ".", 1) == 0)
+			continue;
+		if (file->d_type == DT_DIR) {
+			/* path + '/' + d_name +/0 */
+			path_dir = (char *)malloc(strlen(path) + 2 + sizeof(file->d_name));
+			if (!path_dir) {
+				lxcfs_error("Failed to malloc %s in calc_pid!\n", path);
+				continue;
+			}
+			strcpy(path_dir, path);
+			strcat(path_dir, "/");
+			strcat(path_dir, file->d_name);
+			pd = depth - 1;
+			sum = calc_pid(pid_buf, path_dir, pd, sum, cfd);
+			free(path_dir);
+		}
+	}
+	closedir(dir);
+
+	/* realloc() failed */
+	if (sum == -1)
+		goto out;
+
+	strcat(path, "/cgroup.procs");
+	fd = openat(cfd, path, O_RDONLY);
+	if (fd < 0)
+		goto out;
+
+	f = fdopen(fd, "r");
+	if (!f)
+		goto out;
+
+	while (getline(&line, &linelen, f) != -1) {
+		pid = (char **)realloc(*pid_buf, sizeof(char *) * (sum + 1));
+		if (pid == NULL) {
+			lxcfs_error("%s\n", "realloc error!");
+			for (; sum > 0; sum--)
+				free((*pid_buf)[sum - 1]);
+			sum = -1;
+			goto out;
+		}
+		*pid_buf = pid;
+		do {
+			*(*pid_buf + sum) = (char *)malloc(strlen(line) + 3);
+		} while (*(*pid_buf + sum) == NULL);
+		strcpy(*(*pid_buf + sum), line);
+		sum++;
+	}
+	fclose(f);
+out:
+	free(path);
+	return sum;
+}
+/*
+ * calc_load calculates the load according to the following formula:
+ * load1 = load0 * exp + active * (1 - exp)
+ *
+ * load1: the new loadavg.
+ * load0: the former loadavg.
+ * active: the total number of running pid at this moment.
+ * exp: the fixed-point defined in the beginning.
+ */
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+	unsigned long newload;
+
+	active = active > 0 ? active * FIXED_1 : 0;
+	newload = load * exp + active * (FIXED_1 - exp);
+	if (active >= load)
+		newload += FIXED_1 - 1;
+
+	return newload / FIXED_1;
+}
+
+/*
+ * Return 0 means that container p->cg is closed.
+ * Return -1 means that error occurred in refresh.
+ * Positive num equals the total number of pid.
+ */
+static int refresh_load(struct load_node *p, char *path)
+{
+	FILE *f = NULL;
+	char **idbuf;
+	char proc_path[256];
+	int i, ret, run_pid = 0, total_pid = 0, last_pid = 0;
+	char *line = NULL;
+	size_t linelen = 0;
+	int sum, length;
+	DIR *dp;
+	struct dirent *file;
+
+	idbuf = (char **)malloc(sizeof(char *));
+	if (!idbuf) {
+		lxcfs_error("Refresh container:%s failed for malloc!\n", p->cg);
+		return -1;
+	}
+	sum = calc_pid(&idbuf, path, DEPTH_DIR, 0, p->cfd);
+	/*  normal exit and abnormal exit */
+	if (sum == 0 || sum == -1)
+		goto out;
+
+	for (i = 0; i < sum; i++) {
+		/*clean up '\n' */
+		length = strlen(idbuf[i])-1;
+		idbuf[i][length] = '\0';
+		do {
+			ret = snprintf(proc_path, 256, "/proc/%s/task", idbuf[i]);
+		} while (ret < 0);
+
+		dp = opendir(proc_path);
+		if (!dp) {
+			lxcfs_error("%s\n", "Open proc_path failed in refresh_load.");
+			continue;
+		}
+		while ((file = readdir(dp)) != NULL) {
+			if (strncmp(file->d_name, ".", 1) == 0)
+				continue;
+			total_pid++;
+			/* We make the biggest pid become last_pid.*/
+			ret = atof(file->d_name);
+			last_pid = (ret > last_pid) ? ret : last_pid;
+
+			do {
+				ret = snprintf(proc_path, 256, "/proc/%s/task/%s/status", idbuf[i], file->d_name);
+			} while (ret < 0);
+			f = fopen(proc_path, "r");
+			if (f != NULL) {
+				while (getline(&line, &linelen, f) != -1) {
+					/* Find State */
+					if ((line[0] == 'S') && (line[1] == 't'))
+						break;
+				}
+			if ((line[7] == 'R') || (line[7] == 'D'))
+				run_pid++;
+			fclose(f);
+			}
+		}
+		closedir(dp);
+	}
+	/*Calculate the loadavg.*/
+	p->avenrun[0] = calc_load(p->avenrun[0], EXP_1, run_pid);
+	p->avenrun[1] = calc_load(p->avenrun[1], EXP_5, run_pid);
+	p->avenrun[2] = calc_load(p->avenrun[2], EXP_15, run_pid);
+	p->run_pid = run_pid;
+	p->total_pid = total_pid;
+	p->last_pid = last_pid;
+
+	free(line);
+	for (; i > 0; i--)
+		free(idbuf[i-1]);
+out:
+	free(idbuf);
+	return sum;
+}
+/*
+ * Traverse the hash table and update it.
+ */
+void *load_begin(void *arg)
+{
+
+	char *path = NULL;
+	int i, sum, length, ret;
+	struct load_node *f;
+	int first_node;
+	clock_t time1, time2;
+
+	while (1) {
+		time1 = clock();
+		for (i = 0; i < LOAD_SIZE; i++) {
+			pthread_mutex_lock(&load_hash[i].lock);
+			if (load_hash[i].next == NULL) {
+				pthread_mutex_unlock(&load_hash[i].lock);
+				continue;
+			}
+			f = load_hash[i].next;
+			first_node = 1;
+			while (f) {
+				length = strlen(f->cg) + 2;
+				do {
+					/* strlen(f->cg) + '.' or '' + \0 */
+					path = (char *)malloc(length);
+				} while (!path);
+
+				ret = snprintf(path, length, "%s%s", *(f->cg) == '/' ? "." : "", f->cg);
+				if (ret < 0 || ret > length - 1) {
+					/* snprintf failed, ignore the node.*/
+					lxcfs_error("Refresh node %s failed for snprintf().\n", f->cg);
+					goto out;
+				}
+				sum = refresh_load(f, path);
+				if (sum == 0) {
+					f = del_node(f, i);
+				} else {
+out:				f = f->next;
+				}
+				free(path);
+				/* load_hash[i].lock locks only on the first node.*/
+				if (first_node == 1) {
+					first_node = 0;
+					pthread_mutex_unlock(&load_hash[i].lock);
+				}
+			}
+		}
+		time2 = clock();
+		usleep(FLUSH_TIME * 1000000 - (int)((time2 - time1) * 1000000 / CLOCKS_PER_SEC));
+	}
+}
+
+static int proc_loadavg_read(char *buf, size_t size, off_t offset,
+		struct fuse_file_info *fi)
+{
+	struct fuse_context *fc = fuse_get_context();
+	struct file_info *d = (struct file_info *)fi->fh;
+	pid_t initpid;
+	char *cg;
+	size_t total_len = 0;
+	char *cache = d->buf;
+	struct load_node *n;
+	int hash;
+	int cfd;
+	unsigned long a, b, c;
+
+	if (offset) {
+		if (offset > d->size)
+			return -EINVAL;
+		if (!d->cached)
+			return 0;
+		int left = d->size - offset;
+		total_len = left > size ? size : left;
+		memcpy(buf, cache + offset, total_len);
+		return total_len;
+	}
+	if (!loadavg)
+		return read_file("/proc/loadavg", buf, size, d);
+
+	initpid = lookup_initpid_in_store(fc->pid);
+	if (initpid <= 0)
+		initpid = fc->pid;
+	cg = get_pid_cgroup(initpid, "cpu");
+	if (!cg)
+		return read_file("/proc/loadavg", buf, size, d);
+
+	prune_init_slice(cg);
+	hash = calc_hash(cg);
+	n = locate_node(cg, hash);
+
+	/* First time */
+	if (n == NULL) {
+		if (!find_mounted_controller("cpu", &cfd)) {
+			/*
+			 * In locate_node() above, pthread_rwlock_unlock() isn't used
+			 * because delete is not allowed before read has ended.
+			 */
+			pthread_rwlock_unlock(&load_hash[hash].rdlock);
+			return 0;
+		}
+		n = (struct load_node *)malloc(sizeof(struct load_node));
+		if (!n) {
+			lxcfs_error("Create node %s failed for malloc().\n", cg);
+			pthread_rwlock_unlock(&load_hash[hash].rdlock);
+			return read_file("/proc/loadavg", buf, size, d);
+		}
+		do {
+			n->cg = (char *)malloc(strlen(cg)+1);
+		} while (!n->cg);
+		strcpy(n->cg, cg);
+		n->avenrun[0] = 0;
+		n->avenrun[1] = 0;
+		n->avenrun[2] = 0;
+		n->run_pid = 0;
+		n->total_pid = 1;
+		n->last_pid = initpid;
+		n->cfd = cfd;
+		insert_node(&n, hash);
+	}
+	a = n->avenrun[0] + (FIXED_1/200);
+	b = n->avenrun[1] + (FIXED_1/200);
+	c = n->avenrun[2] + (FIXED_1/200);
+	total_len = snprintf(d->buf, d->buflen, "%lu.%02lu %lu.%02lu %lu.%02lu %d/%d %d\n",
+		LOAD_INT(a), LOAD_FRAC(a),
+		LOAD_INT(b), LOAD_FRAC(b),
+		LOAD_INT(c), LOAD_FRAC(c),
+		n->run_pid, n->total_pid, n->last_pid);
+	pthread_rwlock_unlock(&load_hash[hash].rdlock);
+	if (total_len < 0 || total_len >=  d->buflen) {
+		lxcfs_error("%s\n", "Failed to write to cache");
+		return 0;
+	}
+	d->size = (int)total_len;
+	d->cached = 1;
+
+	if (total_len > size)
+		total_len = size;
+	memcpy(buf, d->buf, total_len);
+	return total_len;
+}
+/* Return a positive number on success, return 0 on failure.*/
+pthread_t load_daemon(int load_use)
+{
+	int ret;
+	pthread_t pid;
+
+	ret = init_load();
+	if (ret == -1) {
+		lxcfs_error("%s\n", "Initialize hash_table fails in load_daemon!");
+		return 0;
+	}
+	ret = pthread_create(&pid, NULL, load_begin, NULL);
+	if (ret != 0) {
+		lxcfs_error("%s\n", "Create pthread fails in load_daemon!");
+		load_free();
+		return 0;
+	}
+	/* use loadavg, here loadavg = 1*/
+	loadavg = load_use;
+	return pid;
+}
+
 static off_t get_procfile_size(const char *which)
 {
 	FILE *f = fopen(which, "r");
diff --git a/bindings.h b/bindings.h
index c663287..a34ac5f 100644
--- a/bindings.h
+++ b/bindings.h
@@ -32,5 +32,6 @@ extern int proc_open(const char *path, struct fuse_file_info *fi);
 extern int proc_read(const char *path, char *buf, size_t size, off_t offset,
 		struct fuse_file_info *fi);
 extern int proc_access(const char *path, int mask);
+extern pthread_t load_daemon(int load_use);
 
 #endif /* __LXCFS_BINDINGS_H */
diff --git a/lxcfs.c b/lxcfs.c
index 62cfd35..848f9b4 100644
--- a/lxcfs.c
+++ b/lxcfs.c
@@ -745,8 +745,9 @@ static void usage()
 {
 	fprintf(stderr, "Usage:\n");
 	fprintf(stderr, "\n");
-	fprintf(stderr, "lxcfs [-f|-d] [-p pidfile] mountpoint\n");
+	fprintf(stderr, "lxcfs [-f|-d] -l [-p pidfile] mountpoint\n");
 	fprintf(stderr, "  -f running foreground by default; -d enable debug output \n");
+	fprintf(stderr, "  -l use loadavg \n");
 	fprintf(stderr, "  Default pidfile is %s/lxcfs.pid\n", RUNTIME_PATH);
 	fprintf(stderr, "lxcfs -h\n");
 	exit(1);
@@ -848,6 +849,10 @@ int main(int argc, char *argv[])
 	char *pidfile = NULL, *v = NULL;
 	size_t pidfile_len;
 	bool debug = false;
+	pthread_t pid;
+	int s = 0;
+	char *error;
+	bool load_use = false;
 	/*
 	 * what we pass to fuse_main is:
 	 * argv[0] -s [-f|-d] -o allow_other,directio argv[1] NULL
@@ -859,6 +864,9 @@ int main(int argc, char *argv[])
 	swallow_arg(&argc, argv, "-s");
 	swallow_arg(&argc, argv, "-f");
 	debug = swallow_arg(&argc, argv, "-d");
+	if (swallow_arg(&argc, argv, "-l")) {
+		load_use = true;
+	}
 	if (swallow_option(&argc, argv, "-o", &v)) {
 		if (strcmp(v, "allow_other") != 0) {
 			fprintf(stderr, "Warning: unexpected fuse option %s\n", v);
@@ -902,6 +910,20 @@ int main(int argc, char *argv[])
 	if ((pidfd = set_pidfile(pidfile)) < 0)
 		goto out;
 
+	if (load_use == true) {
+		dlerror();    /* Clear any existing error */
+		pthread_t (*load_daemon)(int);
+
+		load_daemon = (pthread_t (*)(int)) dlsym(dlopen_handle, "load_daemon");
+		error = dlerror();
+		if (error != NULL) {
+			lxcfs_error("load_daemon fails:%s\n", error);
+			goto out;
+		}
+		pid = load_daemon(1);
+		if (pid == 0)
+			goto out;
+	}
 	if (!fuse_main(nargs, newargv, &lxcfs_ops, NULL))
 		ret = EXIT_SUCCESS;
 

From dfdead46f72e5eef22bccc61bac62af434b992a4 Mon Sep 17 00:00:00 2001
From: zhang2639 <zhangshiqiang at hust.edu.cn>
Date: Wed, 2 May 2018 20:17:15 +0800
Subject: [PATCH 4/4] Claim and use load_free() to free hash table.

Signed-off-by: zhang2639 <zhangshiqiang at hust.edu.cn>
Signed-off-by: yuwang <yuwang at linux.alibaba.com>
---
 bindings.c | 33 +++++++++++++++++++++++++++++++++
 bindings.h |  1 +
 lxcfs.c    | 23 +++++++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/bindings.c b/bindings.c
index edab10e..5c172fc 100644
--- a/bindings.c
+++ b/bindings.c
@@ -247,6 +247,39 @@ static struct load_node *del_node(struct load_node *n, int locate)
 	pthread_rwlock_unlock(&load_hash[locate].rdlock);
 	return g;
 }
+
+void load_free(void)
+{
+	int i;
+	struct load_node *f, *p;
+
+	for (i = 0; i < LOAD_SIZE; i++) {
+		pthread_mutex_lock(&load_hash[i].lock);
+		pthread_rwlock_wrlock(&load_hash[i].rilock);
+		pthread_rwlock_wrlock(&load_hash[i].rdlock);
+		if (load_hash[i].next == NULL) {
+			pthread_mutex_unlock(&load_hash[i].lock);
+			pthread_mutex_destroy(&load_hash[i].lock);
+			pthread_rwlock_unlock(&load_hash[i].rilock);
+			pthread_rwlock_destroy(&load_hash[i].rilock);
+			pthread_rwlock_unlock(&load_hash[i].rdlock);
+			pthread_rwlock_destroy(&load_hash[i].rdlock);
+			continue;
+		}
+		for (f = load_hash[i].next; f; ) {
+			free(f->cg);
+			p = f->next;
+			free(f);
+			f = p;
+		}
+		pthread_mutex_unlock(&load_hash[i].lock);
+		pthread_mutex_destroy(&load_hash[i].lock);
+		pthread_rwlock_unlock(&load_hash[i].rilock);
+		pthread_rwlock_destroy(&load_hash[i].rilock);
+		pthread_rwlock_unlock(&load_hash[i].rdlock);
+		pthread_rwlock_destroy(&load_hash[i].rdlock);
+	}
+}
 /* Reserve buffer size to account for file size changes. */
 #define BUF_RESERVE_SIZE 512
 
diff --git a/bindings.h b/bindings.h
index a34ac5f..6563011 100644
--- a/bindings.h
+++ b/bindings.h
@@ -33,5 +33,6 @@ extern int proc_read(const char *path, char *buf, size_t size, off_t offset,
 		struct fuse_file_info *fi);
 extern int proc_access(const char *path, int mask);
 extern pthread_t load_daemon(int load_use);
+extern void load_free(void);
 
 #endif /* __LXCFS_BINDINGS_H */
diff --git a/lxcfs.c b/lxcfs.c
index 848f9b4..c3535c9 100644
--- a/lxcfs.c
+++ b/lxcfs.c
@@ -926,6 +926,29 @@ int main(int argc, char *argv[])
 	}
 	if (!fuse_main(nargs, newargv, &lxcfs_ops, NULL))
 		ret = EXIT_SUCCESS;
+	
+	if (load_use == true) {
+		s = pthread_cancel(pid);
+		if (s == 0) {
+			s = pthread_join(pid, NULL); /* Make sure sub thread has been canceled. */
+			if (s != 0) {
+				lxcfs_error("%s\n", "load_free error!");
+				goto out;
+			}
+			dlerror();    /* Clear any existing error */
+			void (*load_free)(void);
+
+			load_free = (void (*)(void)) dlsym(dlopen_handle, "load_free");
+			error = dlerror();
+			if (error != NULL) {
+				lxcfs_error("load_free error: %s\n", error);
+				goto out;
+			}
+			load_free();
+		} else {
+			lxcfs_error("%s\n", "load_free error!");
+		}
+	}
 
 out:
 	if (dlopen_handle)


More information about the lxc-devel mailing list