From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Srivatsa S. Bhat" Subject: [PATCH 2/2] netprio_cgroup: Optimize the priomap copy loop slightly Date: Tue, 11 Sep 2012 16:52:37 +0530 Message-ID: <20120911112237.13852.1095.stgit@srivatsabhat.in.ibm.com> References: <20120911112231.13852.61794.stgit@srivatsabhat.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: john.r.fastabend@intel.com, gaofeng@cn.fujitsu.com, eric.dumazet@gmail.com, mark.d.rustad@intel.com, lizefan@huawei.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Srivatsa S. Bhat" To: davem@davemloft.net, nhorman@tuxdriver.com Return-path: In-Reply-To: <20120911112231.13852.61794.stgit@srivatsabhat.in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org * 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 --- 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;