[Devel] [PATCH rh7 1/3] net: Add ipv6 statistics cpu notifier

[Andrei Vagin]

Reviewed-by: Andrei Vagin <avagin at virtuozzo.com>

On Thu, Sep 08, 2016 at 03:06:40PM +0300, Konstantin Khorenko wrote:
> Andrey, please review the patchset.
> 
> --
> Best regards,
> 
> Konstantin Khorenko,
> Virtuozzo Linux Kernel Team
> 
> On 08/25/2016 04:37 PM, Kirill Tkhai wrote:
> > Patch adds a notifier, which moves some ipv6 percpu statistics
> > from died cpu to online cpu.
> > 
> > This allows to do not iterate over all possible cpus during
> > calculation statistics for a user.
> > 
> > This will be used in next patch.
> > 
> > Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
> > ---
> >  net/ipv6/af_inet6.c |   52 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 52 insertions(+)
> > 
> > diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
> > index 082fdaf..6f4c929 100644
> > --- a/net/ipv6/af_inet6.c
> > +++ b/net/ipv6/af_inet6.c
> > @@ -44,6 +44,7 @@
> >  #include <linux/netdevice.h>
> >  #include <linux/icmpv6.h>
> >  #include <linux/netfilter_ipv6.h>
> > +#include <linux/cpu.h>
> > 
> >  #include <net/ip.h>
> >  #include <net/ipv6.h>
> > @@ -700,6 +701,54 @@ bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb)
> >  }
> >  EXPORT_SYMBOL_GPL(ipv6_opt_accepted);
> > 
> > +static void move_ipv6_percpu_stats(int cpu, void **mib, int items)
> > +{
> > +	int this_cpu, i;
> > +
> > +	local_irq_disable();
> > +	this_cpu = smp_processor_id();
> > +
> > +	for (i = 1; i < items; i++) {
> > +		*(((u64 *) per_cpu_ptr(mib[0], this_cpu)) + i) +=
> > +		*(((u64 *) per_cpu_ptr(mib[0], cpu)) + i);
> > +
> > +		*(((u64 *) per_cpu_ptr(mib[0], cpu)) + i) = 0;
> > +	}
> > +	local_irq_enable();
> > +}
> > +
> > +
> > +static int ipv6_cpu_notify(struct notifier_block *self,
> > +			   unsigned long action, void *hcpu)
> > +{
> > +	int cpu = (unsigned long)hcpu;
> > +	struct net_device *dev;
> > +	struct inet6_dev *idev;
> > +	struct net *net;
> > +
> > +	switch (action) {
> > +		case CPU_DEAD:
> > +		case CPU_DEAD_FROZEN:
> > +		rtnl_lock();
> > +		for_each_net(net) {
> > +			for_each_netdev(net, dev) {
> > +				idev = __in6_dev_get(dev);
> > +				if (!idev)
> > +					continue;
> > +				move_ipv6_percpu_stats(cpu,
> > +						(void **)idev->stats.ipv6,
> > +						IPSTATS_MIB_MAX);
> > +			}
> > +		}
> > +		rtnl_unlock();
> > +	}
> > +	return NOTIFY_OK;
> > +}
> > +
> > +static struct notifier_block ipv6_cpu_notifier = {
> > +	.notifier_call  = ipv6_cpu_notify,
> > +};
> > +
> >  static struct packet_type ipv6_packet_type __read_mostly = {
> >  	.type = cpu_to_be16(ETH_P_IPV6),
> >  	.func = ipv6_rcv,
> > @@ -951,6 +1000,7 @@ static int __init inet6_init(void)
> >  	if (err)
> >  		goto sysctl_fail;
> >  #endif
> > +	register_cpu_notifier(&ipv6_cpu_notifier);
> >  out:
> >  	return err;
> > 
> > @@ -1020,6 +1070,8 @@ static void __exit inet6_exit(void)
> >  	if (disable_ipv6_mod)
> >  		return;
> > 
> > +	unregister_cpu_notifier(&ipv6_cpu_notifier);
> > +
> >  	/* First of all disallow new sockets creation. */
> >  	sock_unregister(PF_INET6);
> >  	/* Disallow any further netlink messages */
> > 
> > _______________________________________________
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> > Devel at openvz.org
> > https://lists.openvz.org/mailman/listinfo/devel
> > .
> >