| Message ID | 20221118191909.1756624-2-joel@joelfernandes.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 077c3a5392393c2b8e1289e3b6aeb1bdf0938a81 |
| Headers | show |
| Series | [v2,1/2] net: Use call_rcu_flush() for dst_destroy_rcu | expand |
On Fri, Nov 18, 2022 at 07:19:09PM +0000, Joel Fernandes (Google) wrote: > From: Eric Dumazet <edumazet@google.com> > > Currently, the inetdev_destroy() function waits for an RCU grace period > before decrementing the refcount and freeing memory. This causes a delay > with a new RCU configuration that tries to save power, which results in the > network interface disappearing later than expected. The resulting delay > causes test failures on ChromeOS. > > Refactor the code such that the refcount is freed before the grace period > and memory is freed after. With this a ChromeOS network test passes that > does 'ip netns del' and polls for an interface disappearing, now passes. > > Reported-by: Joel Fernandes (Google) <joel@joelfernandes.org> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Queued and pushed, thank you both! This patch can go as-is based on Eric's Signed-off-by, but the first one of course needs at least an ack. Thanx, Paul > --- > net/ipv4/devinet.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c > index e8b9a9202fec..b0acf6e19aed 100644 > --- a/net/ipv4/devinet.c > +++ b/net/ipv4/devinet.c > @@ -234,13 +234,20 @@ static void inet_free_ifa(struct in_ifaddr *ifa) > call_rcu(&ifa->rcu_head, inet_rcu_free_ifa); > } > > +static void in_dev_free_rcu(struct rcu_head *head) > +{ > + struct in_device *idev = container_of(head, struct in_device, rcu_head); > + > + kfree(rcu_dereference_protected(idev->mc_hash, 1)); > + kfree(idev); > +} > + > void in_dev_finish_destroy(struct in_device *idev) > { > struct net_device *dev = idev->dev; > > WARN_ON(idev->ifa_list); > WARN_ON(idev->mc_list); > - kfree(rcu_dereference_protected(idev->mc_hash, 1)); > #ifdef NET_REFCNT_DEBUG > pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL"); > #endif > @@ -248,7 +255,7 @@ void in_dev_finish_destroy(struct in_device *idev) > if (!idev->dead) > pr_err("Freeing alive in_device %p\n", idev); > else > - kfree(idev); > + call_rcu(&idev->rcu_head, in_dev_free_rcu); > } > EXPORT_SYMBOL(in_dev_finish_destroy); > > @@ -298,12 +305,6 @@ static struct in_device *inetdev_init(struct net_device *dev) > goto out; > } > > -static void in_dev_rcu_put(struct rcu_head *head) > -{ > - struct in_device *idev = container_of(head, struct in_device, rcu_head); > - in_dev_put(idev); > -} > - > static void inetdev_destroy(struct in_device *in_dev) > { > struct net_device *dev; > @@ -328,7 +329,7 @@ static void inetdev_destroy(struct in_device *in_dev) > neigh_parms_release(&arp_tbl, in_dev->arp_parms); > arp_ifdown(dev); > > - call_rcu(&in_dev->rcu_head, in_dev_rcu_put); > + in_dev_put(in_dev); > } > > int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b) > -- > 2.38.1.584.g0f3c55d4c2-goog >
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index e8b9a9202fec..b0acf6e19aed 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -234,13 +234,20 @@ static void inet_free_ifa(struct in_ifaddr *ifa) call_rcu(&ifa->rcu_head, inet_rcu_free_ifa); } +static void in_dev_free_rcu(struct rcu_head *head) +{ + struct in_device *idev = container_of(head, struct in_device, rcu_head); + + kfree(rcu_dereference_protected(idev->mc_hash, 1)); + kfree(idev); +} + void in_dev_finish_destroy(struct in_device *idev) { struct net_device *dev = idev->dev; WARN_ON(idev->ifa_list); WARN_ON(idev->mc_list); - kfree(rcu_dereference_protected(idev->mc_hash, 1)); #ifdef NET_REFCNT_DEBUG pr_debug("%s: %p=%s\n", __func__, idev, dev ? dev->name : "NIL"); #endif @@ -248,7 +255,7 @@ void in_dev_finish_destroy(struct in_device *idev) if (!idev->dead) pr_err("Freeing alive in_device %p\n", idev); else - kfree(idev); + call_rcu(&idev->rcu_head, in_dev_free_rcu); } EXPORT_SYMBOL(in_dev_finish_destroy); @@ -298,12 +305,6 @@ static struct in_device *inetdev_init(struct net_device *dev) goto out; } -static void in_dev_rcu_put(struct rcu_head *head) -{ - struct in_device *idev = container_of(head, struct in_device, rcu_head); - in_dev_put(idev); -} - static void inetdev_destroy(struct in_device *in_dev) { struct net_device *dev; @@ -328,7 +329,7 @@ static void inetdev_destroy(struct in_device *in_dev) neigh_parms_release(&arp_tbl, in_dev->arp_parms); arp_ifdown(dev); - call_rcu(&in_dev->rcu_head, in_dev_rcu_put); + in_dev_put(in_dev); } int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)