Re: [PATCH 1/4] net: Dynamically allocate the per cpu counters for the loopback device.
David Miller [EMAIL PROTECTED] writes: From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Wed, 26 Sep 2007 17:53:40 -0600 This patch add support for dynamically allocating the statistics counters for the loopback device and adds appropriate device methods for allocating and freeing the loopback device. This completes support for creating multiple instances of the loopback device, in preparation for creating per network namespace instances. Signed-off-by: Eric W. Biederman [EMAIL PROTECTED] Applied to net-2.6.24, thanks. @@ -155,7 +154,8 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) dev-last_rx = jiffies; /* it's OK to use __get_cpu_var() because BHs are off */ -lb_stats = __get_cpu_var(pcpu_lstats); +pcpu_lstats = netdev_priv(dev); +lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id()); lb_stats-bytes += skb-len; lb_stats-packets++; I'm going to add a followon change that gets rid of that comment about __get_cpu_var() since it is no longer relevant. Good point. I'm not doing get_cpu/put_cpu so does the comment make sense in relationship to per_cpu_ptr? Eric - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/4] net: Dynamically allocate the per cpu counters for the loopback device.
From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Thu, 27 Sep 2007 01:48:00 -0600 I'm not doing get_cpu/put_cpu so does the comment make sense in relationship to per_cpu_ptr? It is possible. But someone would need to go check for sure. - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/4] net: Dynamically allocate the per cpu counters for the loopback device.
David Miller [EMAIL PROTECTED] writes: From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Thu, 27 Sep 2007 01:48:00 -0600 I'm not doing get_cpu/put_cpu so does the comment make sense in relationship to per_cpu_ptr? It is possible. But someone would need to go check for sure. Verified. hard_start_xmit is called inside of a rcu_read_lock_bh(),rcu_read_unlock_bh() pair. Which means the code will only run on one cpu. Therefore we do not need get_cpu/put_cpu. In addition per_cpu_ptr is valid. As it is just a lookup into a NR_CPUS sized array by smp_processor_id() to return the address of the specific cpu. The only difference between per_cpu_ptr and __get_cpu_var() are the implementation details between statically allocated and dynamically allocated per cpu state. So the comment is still valid, and still interesting it just should say per_cpu_ptr instead of __get_cpu_var. Signed-off-by: Eric W. Biederman [EMAIL PROTECTED] --- diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c index 0f9d8c6..756e267 100644 --- a/drivers/net/loopback.c +++ b/drivers/net/loopback.c @@ -154,7 +154,7 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) #endif dev-last_rx = jiffies; - /* it's OK to use __get_cpu_var() because BHs are off */ + /* it's OK to use per_cpu_ptr() because BHs are off */ pcpu_lstats = netdev_priv(dev); lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id()); lb_stats-bytes += skb-len; - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/4] net: Dynamically allocate the per cpu counters for the loopback device.
From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Thu, 27 Sep 2007 14:44:37 -0600 David Miller [EMAIL PROTECTED] writes: From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Thu, 27 Sep 2007 01:48:00 -0600 I'm not doing get_cpu/put_cpu so does the comment make sense in relationship to per_cpu_ptr? It is possible. But someone would need to go check for sure. Verified. hard_start_xmit is called inside of a rcu_read_lock_bh(),rcu_read_unlock_bh() pair. Which means the code will only run on one cpu. Therefore we do not need get_cpu/put_cpu. In addition per_cpu_ptr is valid. As it is just a lookup into a NR_CPUS sized array by smp_processor_id() to return the address of the specific cpu. The only difference between per_cpu_ptr and __get_cpu_var() are the implementation details between statically allocated and dynamically allocated per cpu state. So the comment is still valid, and still interesting it just should say per_cpu_ptr instead of __get_cpu_var. Signed-off-by: Eric W. Biederman [EMAIL PROTECTED] I've already removed the comment, so you'll have to give me a patch that adds it back with the new content :-) - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/4] net: Dynamically allocate the per cpu counters for the loopback device.
From: [EMAIL PROTECTED] (Eric W. Biederman) Date: Wed, 26 Sep 2007 17:53:40 -0600 This patch add support for dynamically allocating the statistics counters for the loopback device and adds appropriate device methods for allocating and freeing the loopback device. This completes support for creating multiple instances of the loopback device, in preparation for creating per network namespace instances. Signed-off-by: Eric W. Biederman [EMAIL PROTECTED] Applied to net-2.6.24, thanks. @@ -155,7 +154,8 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev) dev-last_rx = jiffies; /* it's OK to use __get_cpu_var() because BHs are off */ - lb_stats = __get_cpu_var(pcpu_lstats); + pcpu_lstats = netdev_priv(dev); + lb_stats = per_cpu_ptr(pcpu_lstats, smp_processor_id()); lb_stats-bytes += skb-len; lb_stats-packets++; I'm going to add a followon change that gets rid of that comment about __get_cpu_var() since it is no longer relevant. - To unsubscribe from this list: send the line unsubscribe netdev in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
