[PATCH 2/2] netprio_cgroup: Optimize the priomap copy loop slightly

[Srivatsa S. Bhat]

* Check for non-NULL old_priomap outside the loop, since its
  not going to change.
* Copy the old_priomap's length to a local variable and use
  that for loop control, instead of costly pointer-dereferences.
Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
---

 net/core/netprio_cgroup.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index fd339bb0..0775bc9 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -73,7 +73,7 @@ static int extend_netdev_table(struct net_device *dev, u32 
new_len)
                           ((sizeof(u32) * new_len));
        struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
        struct netprio_map *old_priomap;
-       int i;
+       int i, old_len;
 
        old_priomap  = rtnl_dereference(dev->priomap);
 
@@ -82,10 +82,12 @@ static int extend_netdev_table(struct net_device *dev, u32 
new_len)
                return -ENOMEM;
        }
 
-       for (i = 0;
-            old_priomap && (i < old_priomap->priomap_len);
-            i++)
-               new_priomap->priomap[i] = old_priomap->priomap[i];
+       if (old_priomap) {
+               old_len = old_priomap->priomap_len;
+
+               for (i = 0; i < old_len; i++)
+                       new_priomap->priomap[i] = old_priomap->priomap[i];
+       }
 
        new_priomap->priomap_len = new_len;
 

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