diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-11-17 05:59:21 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-11-18 05:03:11 -0800 |
| commit | e014debecd3ee3832e6476b3a9c948edfcfd1250 (patch) | |
| tree | 9b73836a5dc3c1df92b17037a12bbbfaf5f495d3 /net/core/dev.c | |
| parent | e2ce146848c81af2f6d42e67990191c284bf0c33 (diff) | |
| download | linux-e014debecd3ee3832e6476b3a9c948edfcfd1250.tar.bz2 | |
linkwatch: linkwatch_forget_dev() to speedup device dismantle
Herbert Xu a écrit :
> On Tue, Nov 17, 2009 at 04:26:04AM -0800, David Miller wrote:
>> Really, the link watch stuff is just due for a redesign. I don't
>> think a simple hack is going to cut it this time, sorry Eric :-)
>
> I have no objections against any redesigns, but since the only
> caller of linkwatch_forget_dev runs in process context with the
> RTNL, it could also legally emit those events.
Thanks guys, here an updated version then, before linkwatch surgery ?
In this version, I force the event to be sent synchronously.
[PATCH net-next-2.6] linkwatch: linkwatch_forget_dev() to speedup device dismantle
time ip link del eth3.103 ; time ip link del eth3.104 ; time ip link del eth3.105
real 0m0.266s
user 0m0.000s
sys 0m0.001s
real 0m0.770s
user 0m0.000s
sys 0m0.000s
real 0m1.022s
user 0m0.000s
sys 0m0.000s
One problem of current schem in vlan dismantle phase is the
holding of device done by following chain :
vlan_dev_stop() ->
netif_carrier_off(dev) ->
linkwatch_fire_event(dev) ->
dev_hold() ...
And __linkwatch_run_queue() runs up to one second later...
A generic fix to this problem is to add a linkwatch_forget_dev() method
to unlink the device from the list of watched devices.
dev->link_watch_next becomes dev->link_watch_list (and use a bit more memory),
to be able to unlink device in O(1).
After patch :
time ip link del eth3.103 ; time ip link del eth3.104 ; time ip link del eth3.105
real 0m0.024s
user 0m0.000s
sys 0m0.000s
real 0m0.032s
user 0m0.000s
sys 0m0.001s
real 0m0.033s
user 0m0.000s
sys 0m0.000s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index e25fe5d9343b..c128af708ebf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5085,6 +5085,8 @@ static void netdev_wait_allrefs(struct net_device *dev) { unsigned long rebroadcast_time, warning_time; + linkwatch_forget_dev(dev); + rebroadcast_time = warning_time = jiffies; while (atomic_read(&dev->refcnt) != 0) { if (time_after(jiffies, rebroadcast_time + 1 * HZ)) { @@ -5311,6 +5313,7 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name, INIT_LIST_HEAD(&dev->napi_list); INIT_LIST_HEAD(&dev->unreg_list); + INIT_LIST_HEAD(&dev->link_watch_list); dev->priv_flags = IFF_XMIT_DST_RELEASE; setup(dev); strcpy(dev->name, name); |