[PATCH net-next] ethtool: Declare netdev_rss_key as __read_mostly.

[PATCH net-next] ethtool: Declare netdev_rss_key as __read_mostly.

[Kim Jones]

netdev_rss_key is written to once and thereafter is read by
drivers when they are initialising. The fact that it is mostly
read and not written to makes it a candidate for a __read_mostly
declaration.

Signed-off-by: Kim Jones <kim-marie.jones@intel.com>
Signed-off-by: Alan Carey <alan.carey@intel.com>
Acked-by: Rami Rosen <rami.rosen@intel.com>
---
 include/linux/netdevice.h | 2 +-
 net/core/ethtool.c        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5ac140d..ec184a2 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3742,7 +3742,7 @@ void netdev_lower_state_changed(struct net_device *lower_dev,
 
 /* RSS keys are 40 or 52 bytes long */
 #define NETDEV_RSS_KEY_LEN 52
-extern u8 netdev_rss_key[NETDEV_RSS_KEY_LEN];
+extern u8 netdev_rss_key[NETDEV_RSS_KEY_LEN] __read_mostly;
 void netdev_rss_key_fill(void *buffer, size_t len);
 
 int dev_get_nest_level(struct net_device *dev,
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index daf0470..453c803 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -632,7 +632,7 @@ static int ethtool_copy_validate_indir(u32 *indir, void __user *useraddr,
 	return 0;
 }
 
-u8 netdev_rss_key[NETDEV_RSS_KEY_LEN];
+u8 netdev_rss_key[NETDEV_RSS_KEY_LEN] __read_mostly;
 
 void netdev_rss_key_fill(void *buffer, size_t len)
 {
-- 
2.1.0

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Re: [PATCH net-next] ethtool: Declare netdev_rss_key as __read_mostly.

[David Miller]

From: Kim Jones <kim-marie.jones@intel.com>
Date: Tue,  2 Feb 2016 03:51:16 +0000

> netdev_rss_key is written to once and thereafter is read by
> drivers when they are initialising. The fact that it is mostly
> read and not written to makes it a candidate for a __read_mostly
> declaration.
> 
> Signed-off-by: Kim Jones <kim-marie.jones@intel.com>
> Signed-off-by: Alan Carey <alan.carey@intel.com>
> Acked-by: Rami Rosen <rami.rosen@intel.com>

Applied, thank you.