| Message ID | 1467090824.6850.185.camel@edumazet-glaptop3.roam.corp.google.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On 2016/6/28 13:13, Eric Dumazet wrote: > On Tue, 2016-06-28 at 12:56 +0800, Ding Tianhong wrote: >> The problem was occurs in my system that a lot of drviers register >> its own handler to the notifiler call chain for netdev_chain, and >> then create 4095 vlan dev for one nic, and add several ipv6 address >> on each one of them, just like this: >> >> for i in `seq 1 4095`; do ip link add link eth0 name eth0.$i type vlan id $i; done >> for i in `seq 1 4095`; do ip -6 addr add 2001::$i dev eth0.$i; done >> for i in `seq 1 4095`; do ip -6 addr add 2002::$i dev eth0.$i; done >> for i in `seq 1 4095`; do ip -6 addr add 2003::$i dev eth0.$i; done >> >> ifconfig eth0 up >> ifconfig eth0 down > > I would very much prefer cond_resched() at a more appropriate place. > > touch_nmi_watchdog() does not fundamentally solve the issue, as some > process is holding one cpu for a very long time. > > Probably in addrconf_ifdown(), as if you have 100,000 IPv6 addresses on > a single netdev, this function might also trigger a soft lockup, without > playing with 4096 vlans... > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index a1f6b7b315317f811cafbf386cf21dfc510c2010..13b675f79a751db45af28fc0474ddb17d9b69b06 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -3566,6 +3566,7 @@ restart: > } > } > spin_unlock_bh(&addrconf_hash_lock); > + cond_resched(); > } > > write_lock_bh(&idev->lock); > > it looks like not enough, I still got this calltrace, <4>[ 7618.596184]3840: ffffffbfa101a0a0 00000000000007f0 <4>[ 7618.596187][<ffffffc000203780>] el1_irq+0x80/0x100 <4>[ 7618.596255][<ffffffbfa1019d74>] fib6_walk_continue+0x1d4/0x200 [ipv6] <4>[ 7618.596275][<ffffffbfa1019ed4>] fib6_walk+0x3c/0x70 [ipv6] <4>[ 7618.596295][<ffffffbfa1019f70>] fib6_clean_tree+0x68/0x90 [ipv6] <4>[ 7618.596314][<ffffffbfa101a020>] __fib6_clean_all+0x88/0xc0 [ipv6] <4>[ 7618.596334][<ffffffbfa101c7f0>] fib6_run_gc+0x88/0x148 [ipv6] <4>[ 7618.596354][<ffffffbfa1021678>] ndisc_netdev_event+0x80/0x140 [ipv6] <4>[ 7618.596358][<ffffffc00023f83c>] notifier_call_chain+0x5c/0xa0 <4>[ 7618.596361][<ffffffc00023f9e0>] raw_notifier_call_chain+0x20/0x28 <4>[ 7618.596366][<ffffffc0005cbab4>] call_netdevice_notifiers_info+0x4c/0x80 <4>[ 7618.596369][<ffffffc0005cbfc8>] dev_close_many+0xd0/0x138 <4>[ 7618.596378][<ffffffbfa33be6e8>] vlan_device_event+0x4a8/0x6a0 [8021q] <4>[ 7618.596381][<ffffffc00023f83c>] notifier_call_chain+0x5c/0xa0 <4>[ 7618.596384][<ffffffc00023f9e0>] raw_notifier_call_chain+0x20/0x28 <4>[ 7618.596387][<ffffffc0005cbab4>] call_netdevice_notifiers_info+0x4c/0x80 <4>[ 7618.596390][<ffffffc0005d5148>] __dev_notify_flags+0xb8/0xe0 <4>[ 7618.596393][<ffffffc0005d5994>] dev_change_flags+0x54/0x68 <4>[ 7618.596397][<ffffffc00064a620>] devinet_ioctl+0x650/0x700 <4>[ 7618.596400][<ffffffc00064bea4>] inet_ioctl+0xa4/0xc8 <4>[ 7618.596405][<ffffffc0005b1094>] sock_do_ioctl+0x44/0x88 <4>[ 7618.596408][<ffffffc0005b1a3c>] sock_ioctl+0x23c/0x308 <4>[ 7618.596413][<ffffffc000393bc4>] do_vfs_ioctl+0x48c/0x620 > > > . >
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index a1f6b7b315317f811cafbf386cf21dfc510c2010..13b675f79a751db45af28fc0474ddb17d9b69b06 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3566,6 +3566,7 @@ restart: } } spin_unlock_bh(&addrconf_hash_lock); + cond_resched(); } write_lock_bh(&idev->lock);