summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--net/sctp/protocol.c47
1 files changed, 38 insertions, 9 deletions
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index e13c3c3ea4ac..9d134ab3351f 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -60,6 +60,8 @@
#include <net/inet_common.h>
#include <net/inet_ecn.h>
+#define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
+
/* Global data structures. */
struct sctp_globals sctp_globals __read_mostly;
@@ -1332,6 +1334,8 @@ static __init int sctp_init(void)
unsigned long limit;
int max_share;
int order;
+ int num_entries;
+ int max_entry_order;
sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
@@ -1384,14 +1388,24 @@ static __init int sctp_init(void)
/* Size and allocate the association hash table.
* The methodology is similar to that of the tcp hash tables.
+ * Though not identical. Start by getting a goal size
*/
if (totalram_pages >= (128 * 1024))
goal = totalram_pages >> (22 - PAGE_SHIFT);
else
goal = totalram_pages >> (24 - PAGE_SHIFT);
- for (order = 0; (1UL << order) < goal; order++)
- ;
+ /* Then compute the page order for said goal */
+ order = get_order(goal);
+
+ /* Now compute the required page order for the maximum sized table we
+ * want to create
+ */
+ max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
+ sizeof(struct sctp_bind_hashbucket));
+
+ /* Limit the page order by that maximum hash table size */
+ order = min(order, max_entry_order);
do {
sctp_assoc_hashsize = (1UL << order) * PAGE_SIZE /
@@ -1425,27 +1439,42 @@ static __init int sctp_init(void)
INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
}
- /* Allocate and initialize the SCTP port hash table. */
+ /* Allocate and initialize the SCTP port hash table.
+ * Note that order is initalized to start at the max sized
+ * table we want to support. If we can't get that many pages
+ * reduce the order and try again
+ */
do {
- sctp_port_hashsize = (1UL << order) * PAGE_SIZE /
- sizeof(struct sctp_bind_hashbucket);
- if ((sctp_port_hashsize > (64 * 1024)) && order > 0)
- continue;
sctp_port_hashtable = (struct sctp_bind_hashbucket *)
__get_free_pages(GFP_ATOMIC|__GFP_NOWARN, order);
} while (!sctp_port_hashtable && --order > 0);
+
if (!sctp_port_hashtable) {
pr_err("Failed bind hash alloc\n");
status = -ENOMEM;
goto err_bhash_alloc;
}
+
+ /* Now compute the number of entries that will fit in the
+ * port hash space we allocated
+ */
+ num_entries = (1UL << order) * PAGE_SIZE /
+ sizeof(struct sctp_bind_hashbucket);
+
+ /* And finish by rounding it down to the nearest power of two
+ * this wastes some memory of course, but its needed because
+ * the hash function operates based on the assumption that
+ * that the number of entries is a power of two
+ */
+ sctp_port_hashsize = rounddown_pow_of_two(num_entries);
+
for (i = 0; i < sctp_port_hashsize; i++) {
spin_lock_init(&sctp_port_hashtable[i].lock);
INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
}
- pr_info("Hash tables configured (established %d bind %d)\n",
- sctp_assoc_hashsize, sctp_port_hashsize);
+ pr_info("Hash tables configured (established %d bind %d/%d)\n",
+ sctp_assoc_hashsize, sctp_port_hashsize, num_entries);
sctp_sysctl_register();