[IPV4]: possible cleanups

[safe/jmp/linux-2.6] / net / core / request_sock.c

diff --git a/net/core/request_sock.c b/net/core/request_sock.c
index 1258333..98f0fc9 100644 (file)
--- a/net/core/request_sock.c
+++ b/net/core/request_sock.c
@@ -18,12 +18,27 @@
 
 #include <net/request_sock.h>
 
+/*
+ * Maximum number of SYN_RECV sockets in queue per LISTEN socket.
+ * One SYN_RECV socket costs about 80bytes on a 32bit machine.
+ * It would be better to replace it with a global counter for all sockets
+ * but then some measure against one socket starving all other sockets
+ * would be needed.
+ *
+ * It was 128 by default. Experiments with real servers show, that
+ * it is absolutely not enough even at 100conn/sec. 256 cures most
+ * of problems. This value is adjusted to 128 for very small machines
+ * (<=32Mb of memory) and to 1024 on normal or better ones (>=256Mb).
+ * Further increasing requires to change hash table size.
+ */
+int sysctl_max_syn_backlog = 256;
+
 int reqsk_queue_alloc(struct request_sock_queue *queue,
                      const int nr_table_entries)
 {
-       const int lopt_size = sizeof(struct tcp_listen_opt) +
+       const int lopt_size = sizeof(struct listen_sock) +
                              nr_table_entries * sizeof(struct request_sock *);
-       struct tcp_listen_opt *lopt = kmalloc(lopt_size, GFP_KERNEL);
+       struct listen_sock *lopt = kmalloc(lopt_size, GFP_KERNEL);
 
        if (lopt == NULL)
                return -ENOMEM;
@@ -37,6 +52,7 @@ int reqsk_queue_alloc(struct request_sock_queue *queue,
        get_random_bytes(&lopt->hash_rnd, sizeof(lopt->hash_rnd));
        rwlock_init(&queue->syn_wait_lock);
        queue->rskq_accept_head = queue->rskq_accept_head = NULL;
+       lopt->nr_table_entries = nr_table_entries;
 
        write_lock_bh(&queue->syn_wait_lock);
        queue->listen_opt = lopt;
@@ -46,3 +62,28 @@ int reqsk_queue_alloc(struct request_sock_queue *queue,
 }
 
 EXPORT_SYMBOL(reqsk_queue_alloc);
+
+void reqsk_queue_destroy(struct request_sock_queue *queue)
+{
+       /* make all the listen_opt local to us */
+       struct listen_sock *lopt = reqsk_queue_yank_listen_sk(queue);
+
+       if (lopt->qlen != 0) {
+               int i;
+
+               for (i = 0; i < lopt->nr_table_entries; i++) {
+                       struct request_sock *req;
+
+                       while ((req = lopt->syn_table[i]) != NULL) {
+                               lopt->syn_table[i] = req->dl_next;
+                               lopt->qlen--;
+                               reqsk_free(req);
+                       }
+               }
+       }
+
+       BUG_TRAP(lopt->qlen == 0);
+       kfree(lopt);
+}
+
+EXPORT_SYMBOL(reqsk_queue_destroy);