bonding: optimize tlb_get_least_loaded_slave

In the worst case, when the first loop breaks an the end of the slave list,
the slave list is iterated through twice. This patch reduces this
function only to one loop. Also makes it simpler.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko 2010-05-19 03:26:39 +00:00 committed by David S. Miller
parent 5206e24c2c
commit 097811bb48

View File

@ -233,34 +233,27 @@ static void tlb_deinitialize(struct bonding *bond)
_unlock_tx_hashtbl(bond);
}
static long long compute_gap(struct slave *slave)
{
return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
(s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
}
/* Caller must hold bond lock for read */
static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)
{
struct slave *slave, *least_loaded;
s64 max_gap;
int i, found = 0;
long long max_gap;
int i;
/* Find the first enabled slave */
bond_for_each_slave(bond, slave, i) {
if (SLAVE_IS_OK(slave)) {
found = 1;
break;
}
}
if (!found) {
return NULL;
}
least_loaded = slave;
max_gap = (s64)(slave->speed << 20) - /* Convert to Megabit per sec */
(s64)(SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
least_loaded = NULL;
max_gap = LLONG_MIN;
/* Find the slave with the largest gap */
bond_for_each_slave_from(bond, slave, i, least_loaded) {
bond_for_each_slave(bond, slave, i) {
if (SLAVE_IS_OK(slave)) {
s64 gap = (s64)(slave->speed << 20) -
(s64)(SLAVE_TLB_INFO(slave).load << 3);
long long gap = compute_gap(slave);
if (max_gap < gap) {
least_loaded = slave;
max_gap = gap;