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-rw-r--r--net/sctp/protocol.c46
1 files changed, 38 insertions, 8 deletions
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index ab0d538a74ed..1099e99a53c4 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;
@@ -1355,6 +1357,8 @@ 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));
@@ -1407,14 +1411,24 @@ 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);
/* Allocate and initialize the endpoint hash table. */
sctp_ep_hashsize = 64;
@@ -1430,20 +1444,35 @@ 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_KERNEL | __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);
@@ -1452,7 +1481,8 @@ static __init int sctp_init(void)
if (sctp_transport_hashtable_init())
goto err_thash_alloc;
- pr_info("Hash tables configured (bind %d)\n", sctp_port_hashsize);
+ pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
+ num_entries);
sctp_sysctl_register();