| Message ID | 20081028133124.GA3006@x200.localdomain |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Alexey Dobriyan wrote: > call_rcu() will unconditionally rewrite RCU head anyway. > Applies to > struct neigh_parms > struct neigh_table > struct net > struct cipso_v4_doi > struct in_ifaddr > struct in_device > rt->u.dst It would probably make sense to get a statement from Paul whether this might be required in the future, f.i. for some debugging feature. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 28, 2008 at 04:29:06PM +0100, Patrick McHardy wrote: > Alexey Dobriyan wrote: >> call_rcu() will unconditionally rewrite RCU head anyway. >> Applies to struct neigh_parms >> struct neigh_table >> struct net >> struct cipso_v4_doi >> struct in_ifaddr >> struct in_device >> rt->u.dst > > It would probably make sense to get a statement from Paul > whether this might be required in the future, f.i. for some > debugging feature. Let's cc him :-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 28, 2008 at 06:43:41PM +0300, Alexey Dobriyan wrote: > On Tue, Oct 28, 2008 at 04:29:06PM +0100, Patrick McHardy wrote: > > Alexey Dobriyan wrote: > >> call_rcu() will unconditionally rewrite RCU head anyway. > >> Applies to struct neigh_parms > >> struct neigh_table > >> struct net > >> struct cipso_v4_doi > >> struct in_ifaddr > >> struct in_device > >> rt->u.dst > > > > It would probably make sense to get a statement from Paul > > whether this might be required in the future, f.i. for some > > debugging feature. > > Let's cc him :-) Can't say that I would be all that upset if INIT_RCU_HEAD() were to simply vanish. So I have no problem with it being removed from the above functions. Suppose I might as well find the original and Ack it. ;-) Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 28, 2008 at 04:31:24PM +0300, Alexey Dobriyan wrote: > call_rcu() will unconditionally rewrite RCU head anyway. > Applies to > struct neigh_parms > struct neigh_table > struct net > struct cipso_v4_doi > struct in_ifaddr > struct in_device > rt->u.dst Assuming that no code outside of RCU is testing the rcu_head fields... That would usually be a bad idea in any case, as call_rcu() makes no guarantee about the values of these fields after the callback is invoked. Furthermore, there have been serious proposals that would change the call_rcu() field names and layout. Therefore: Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> > --- > > net/core/neighbour.c | 2 -- > net/core/net_namespace.c | 2 -- > net/ipv4/cipso_ipv4.c | 1 - > net/ipv4/devinet.c | 9 +-------- > net/ipv4/route.c | 1 - > 5 files changed, 1 insertion(+), 14 deletions(-) > > --- a/net/core/neighbour.c > +++ b/net/core/neighbour.c > @@ -1340,7 +1340,6 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev, > if (p) { > p->tbl = tbl; > atomic_set(&p->refcnt, 1); > - INIT_RCU_HEAD(&p->rcu_head); > p->reachable_time = > neigh_rand_reach_time(p->base_reachable_time); > > @@ -1412,7 +1411,6 @@ void neigh_table_init_no_netlink(struct neigh_table *tbl) > tbl->parms.net = &init_net; > #endif > atomic_set(&tbl->parms.refcnt, 1); > - INIT_RCU_HEAD(&tbl->parms.rcu_head); > tbl->parms.reachable_time = > neigh_rand_reach_time(tbl->parms.base_reachable_time); > > --- a/net/core/net_namespace.c > +++ b/net/core/net_namespace.c > @@ -47,7 +47,6 @@ static __net_init int setup_net(struct net *net) > goto out; > > ng->len = INITIAL_NET_GEN_PTRS; > - INIT_RCU_HEAD(&ng->rcu); > rcu_assign_pointer(net->gen, ng); > > error = 0; > @@ -446,7 +445,6 @@ int net_assign_generic(struct net *net, int id, void *data) > */ > > ng->len = id; > - INIT_RCU_HEAD(&ng->rcu); > memcpy(&ng->ptr, &old_ng->ptr, old_ng->len); > > rcu_assign_pointer(net->gen, ng); > --- a/net/ipv4/cipso_ipv4.c > +++ b/net/ipv4/cipso_ipv4.c > @@ -490,7 +490,6 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) > } > > atomic_set(&doi_def->refcount, 1); > - INIT_RCU_HEAD(&doi_def->rcu); > > spin_lock(&cipso_v4_doi_list_lock); > if (cipso_v4_doi_search(doi_def->doi) != NULL) > --- a/net/ipv4/devinet.c > +++ b/net/ipv4/devinet.c > @@ -112,13 +112,7 @@ static inline void devinet_sysctl_unregister(struct in_device *idev) > > static struct in_ifaddr *inet_alloc_ifa(void) > { > - struct in_ifaddr *ifa = kzalloc(sizeof(*ifa), GFP_KERNEL); > - > - if (ifa) { > - INIT_RCU_HEAD(&ifa->rcu_head); > - } > - > - return ifa; > + return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL); > } > > static void inet_rcu_free_ifa(struct rcu_head *head) > @@ -161,7 +155,6 @@ static struct in_device *inetdev_init(struct net_device *dev) > in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL); > if (!in_dev) > goto out; > - INIT_RCU_HEAD(&in_dev->rcu_head); > memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt, > sizeof(in_dev->cnf)); > in_dev->cnf.sysctl = NULL; > --- a/net/ipv4/route.c > +++ b/net/ipv4/route.c > @@ -1386,7 +1386,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, > > /* Copy all the information. */ > *rt = *rth; > - INIT_RCU_HEAD(&rt->u.dst.rcu_head); > rt->u.dst.__use = 1; > atomic_set(&rt->u.dst.__refcnt, 1); > rt->u.dst.child = NULL; > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Date: Tue, 28 Oct 2008 09:10:17 -0700 > On Tue, Oct 28, 2008 at 04:31:24PM +0300, Alexey Dobriyan wrote: > > call_rcu() will unconditionally rewrite RCU head anyway. > > Applies to > > struct neigh_parms > > struct neigh_table > > struct net > > struct cipso_v4_doi > > struct in_ifaddr > > struct in_device > > rt->u.dst > > Assuming that no code outside of RCU is testing the rcu_head fields... > That would usually be a bad idea in any case, as call_rcu() makes no > guarantee about the values of these fields after the callback is invoked. > Furthermore, there have been serious proposals that would change the > call_rcu() field names and layout. > > Therefore: > > Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> I've applied this patch, thanks everyone. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1340,7 +1340,6 @@ struct neigh_parms *neigh_parms_alloc(struct net_device *dev, if (p) { p->tbl = tbl; atomic_set(&p->refcnt, 1); - INIT_RCU_HEAD(&p->rcu_head); p->reachable_time = neigh_rand_reach_time(p->base_reachable_time); @@ -1412,7 +1411,6 @@ void neigh_table_init_no_netlink(struct neigh_table *tbl) tbl->parms.net = &init_net; #endif atomic_set(&tbl->parms.refcnt, 1); - INIT_RCU_HEAD(&tbl->parms.rcu_head); tbl->parms.reachable_time = neigh_rand_reach_time(tbl->parms.base_reachable_time); --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -47,7 +47,6 @@ static __net_init int setup_net(struct net *net) goto out; ng->len = INITIAL_NET_GEN_PTRS; - INIT_RCU_HEAD(&ng->rcu); rcu_assign_pointer(net->gen, ng); error = 0; @@ -446,7 +445,6 @@ int net_assign_generic(struct net *net, int id, void *data) */ ng->len = id; - INIT_RCU_HEAD(&ng->rcu); memcpy(&ng->ptr, &old_ng->ptr, old_ng->len); rcu_assign_pointer(net->gen, ng); --- a/net/ipv4/cipso_ipv4.c +++ b/net/ipv4/cipso_ipv4.c @@ -490,7 +490,6 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def) } atomic_set(&doi_def->refcount, 1); - INIT_RCU_HEAD(&doi_def->rcu); spin_lock(&cipso_v4_doi_list_lock); if (cipso_v4_doi_search(doi_def->doi) != NULL) --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -112,13 +112,7 @@ static inline void devinet_sysctl_unregister(struct in_device *idev) static struct in_ifaddr *inet_alloc_ifa(void) { - struct in_ifaddr *ifa = kzalloc(sizeof(*ifa), GFP_KERNEL); - - if (ifa) { - INIT_RCU_HEAD(&ifa->rcu_head); - } - - return ifa; + return kzalloc(sizeof(struct in_ifaddr), GFP_KERNEL); } static void inet_rcu_free_ifa(struct rcu_head *head) @@ -161,7 +155,6 @@ static struct in_device *inetdev_init(struct net_device *dev) in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL); if (!in_dev) goto out; - INIT_RCU_HEAD(&in_dev->rcu_head); memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt, sizeof(in_dev->cnf)); in_dev->cnf.sysctl = NULL; --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1386,7 +1386,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, /* Copy all the information. */ *rt = *rth; - INIT_RCU_HEAD(&rt->u.dst.rcu_head); rt->u.dst.__use = 1; atomic_set(&rt->u.dst.__refcnt, 1); rt->u.dst.child = NULL;
call_rcu() will unconditionally rewrite RCU head anyway. Applies to struct neigh_parms struct neigh_table struct net struct cipso_v4_doi struct in_ifaddr struct in_device rt->u.dst Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> --- net/core/neighbour.c | 2 -- net/core/net_namespace.c | 2 -- net/ipv4/cipso_ipv4.c | 1 - net/ipv4/devinet.c | 9 +-------- net/ipv4/route.c | 1 - 5 files changed, 1 insertion(+), 14 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html