Make lsof 10x faster by caching /proc/net socket info.
I deliberately didn't do this first time round because for me our lsof
is already 10x faster than traditional lsof, and caching means we potentially
give less information about a socket that's created while we're running.
It turns out that traditional lsof caches anyway, so I guess nobody cares.
This also fixes a mistake where lsof used CFG_FREE instead of CFG_TOYBOX_FREE.
diff --git a/toys/pending/lsof.c b/toys/pending/lsof.c
index 3a1c7f7..e99b011 100644
--- a/toys/pending/lsof.c
+++ b/toys/pending/lsof.c
@@ -26,6 +26,7 @@
struct stat *sought_files;
+ struct double_list *all_sockets;
struct double_list *files;
int last_shown_pid;
int shown_header;
@@ -81,11 +82,12 @@
fi->fd, fi->rw, fi->locks, fi->type, fi->device, fi->size_off,
fi->node, fi->name);
}
+}
- if (CFG_FREE) {
- free(((struct file_info *)data)->name);
- free(data);
- }
+static void free_info(void *data)
+{
+ free(((struct file_info *)data)->name);
+ free(data);
}
static void fill_flags(struct file_info *fi)
@@ -109,46 +111,49 @@
fclose(fp);
}
-static int scan_proc_net_file(char *path, int family, char type,
- void (*fn)(char *, int, char, struct file_info *, long),
- struct file_info *fi, long sought_inode)
+static void scan_proc_net_file(char *path, int family, char type,
+ void (*fn)(char *, int, char))
{
FILE *fp = fopen(path, "r");
char *line = NULL;
size_t line_length = 0;
- if (!fp) return 0;
+ if (!fp) return;
- if (!getline(&line, &line_length, fp)) return 0; // Skip header.
+ if (!getline(&line, &line_length, fp)) return; // Skip header.
while (getline(&line, &line_length, fp) > 0) {
- fn(line, family, type, fi, sought_inode);
- if (fi->name != 0) break;
+ fn(line, family, type);
}
free(line);
fclose(fp);
-
- return fi->name != 0;
}
-static void match_unix(char *line, int af, char type, struct file_info *fi,
- long sought_inode)
+static struct file_info *add_socket(ino_t inode, const char *type)
+{
+ struct file_info *fi = xzalloc(sizeof(struct file_info));
+
+ dlist_add_nomalloc(&TT.all_sockets, (struct double_list *)fi);
+ fi->st_ino = inode;
+ strcpy(fi->type, type);
+ return fi;
+}
+
+static void scan_unix(char *line, int af, char type)
{
long inode;
int path_pos;
- if (sscanf(line, "%*p: %*X %*X %*X %*X %*X %lu %n", &inode, &path_pos) >= 1 &&
- inode == sought_inode) {
+ if (sscanf(line, "%*p: %*X %*X %*X %*X %*X %lu %n", &inode, &path_pos) >= 1) {
+ struct file_info *fi = add_socket(inode, "unix");
char *name = chomp(line + path_pos);
- strcpy(fi->type, "unix");
fi->name = strdup(*name ? name : "socket");
}
}
-static void match_netlink(char *line, int af, char type, struct file_info *fi,
- long sought_inode)
+static void scan_netlink(char *line, int af, char type)
{
unsigned state;
long inode;
@@ -159,18 +164,17 @@
"ENCRYPTFS", "RDMA", "CRYPTO"
};
- if (sscanf(line, "%*p %u %*u %*x %*u %*u %*u %*u %*u %lu",
- &state, &inode) < 2 || inode != sought_inode) {
+ if (sscanf(line, "%*p %u %*u %*x %*u %*u %*u %*u %*u %lu", &state, &inode)
+ < 2) {
return;
}
- strcpy(fi->type, "netlink");
+ struct file_info *fi = add_socket(inode, "netlink");
fi->name =
strdup(state < ARRAY_LEN(netlink_states) ? netlink_states[state] : "?");
}
-static void match_ip(char *line, int af, char type, struct file_info *fi,
- long sought_inode)
+static void scan_ip(char *line, int af, char type)
{
char *tcp_states[] = {
"UNKNOWN", "ESTABLISHED", "SYN_SENT", "SYN_RECV", "FIN_WAIT1", "FIN_WAIT2",
@@ -198,9 +202,9 @@
&(remote.s6_addr32[2]), &(remote.s6_addr32[3]),
&remote_port, &state, &inode) == 12;
}
- if (!ok || inode != sought_inode) return;
+ if (!ok) return;
- strcpy(fi->type, af == 4 ? "IPv4" : "IPv6");
+ struct file_info *fi = add_socket(inode, af == 4 ? "IPv4" : "IPv6");
inet_ntop(af, &local, local_ip, sizeof(local_ip));
inet_ntop(af, &remote, remote_ip, sizeof(remote_ip));
if (type == 't') {
@@ -219,15 +223,32 @@
static int find_socket(struct file_info *fi, long inode)
{
- // TODO: other protocols (packet).
- return scan_proc_net_file("/proc/net/tcp", 4, 't', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/tcp6", 6, 't', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/udp", 4, 'u', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/udp6", 6, 'u', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/raw", 4, 'r', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/raw6", 6, 'r', match_ip, fi, inode) ||
- scan_proc_net_file("/proc/net/unix", 0, 0, match_unix, fi, inode) ||
- scan_proc_net_file("/proc/net/netlink", 0, 0, match_netlink, fi, inode);
+ static int cached;
+ if (!cached) {
+ scan_proc_net_file("/proc/net/tcp", 4, 't', scan_ip);
+ scan_proc_net_file("/proc/net/tcp6", 6, 't', scan_ip);
+ scan_proc_net_file("/proc/net/udp", 4, 'u', scan_ip);
+ scan_proc_net_file("/proc/net/udp6", 6, 'u', scan_ip);
+ scan_proc_net_file("/proc/net/raw", 4, 'r', scan_ip);
+ scan_proc_net_file("/proc/net/raw6", 6, 'r', scan_ip);
+ scan_proc_net_file("/proc/net/unix", 0, 0, scan_unix);
+ scan_proc_net_file("/proc/net/netlink", 0, 0, scan_netlink);
+ cached = 1;
+ }
+ void* list = TT.all_sockets;
+
+ while (list) {
+ struct file_info *s = (struct file_info*) llist_pop(&list);
+
+ if (s->st_ino == inode) {
+ fi->name = s->name ? strdup(s->name) : NULL;
+ strcpy(fi->type, s->type);
+ return 1;
+ }
+ if (list == TT.all_sockets) break;
+ }
+
+ return 0;
}
static void fill_stat(struct file_info *fi, const char *path)
@@ -442,4 +463,9 @@
}
llist_traverse(TT.files, print_info);
+
+ if (CFG_TOYBOX_FREE) {
+ llist_traverse(TT.files, free_info);
+ llist_traverse(TT.all_sockets, free_info);
+ }
}
