| Message ID | bc33a6142ce48b71b9c232a9154ed76f6048f0cb.1318068629.git.panweiping3@gmail.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
Hi, Herbert, What do you think of this patch ? thanks Weiping Pan On 10/08/2011 06:12 PM, Weiping Pan wrote: > Default mtu of vlan device is the same with mtu of physical device, > for example 1500, but when change physics mtu to 1600, > VLAN device's mtu is still 1500. > Certainly, you can change vlan device's mtu to 1600 manually, > but I think when you change physics device's mtu, VLAN's mtu should be changed > automatically instead of by manually. > > Steps to Reproduce: > 1.vconfig add eth4 3 > 2.ifconfig eth4 mtu 1600 > 3.check mtu on eth4.3 > > And what's worse is that if you decrease mtu of pyhsical device, > and when you want to increase it, the mtu of vlan device won't be changed. > > Steps to Reproduce: > 1.vconfig add eth4 3 > 2.ifconfig eth4 mtu 100 > 3.ifconfig eth4 mtu 1500 > 4.the mtu of eth4.3 is still 100 > > This bug is reported by Liang Zheng(lzheng@redhat.com). > > Signed-off-by: Weiping Pan<panweiping3@gmail.com> > --- > net/8021q/vlan.c | 3 --- > 1 files changed, 0 insertions(+), 3 deletions(-) > > diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c > index 8970ba1..f6072b4 100644 > --- a/net/8021q/vlan.c > +++ b/net/8021q/vlan.c > @@ -417,9 +417,6 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, > if (!vlandev) > continue; > > - if (vlandev->mtu<= dev->mtu) > - continue; > - > dev_set_mtu(vlandev, dev->mtu); > } > break; -- 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 10/18/2011 07:06 PM, WeipingPan wrote: > Hi, Herbert, > > What do you think of this patch ? > > thanks > Weiping Pan > On 10/08/2011 06:12 PM, Weiping Pan wrote: >> Default mtu of vlan device is the same with mtu of physical device, >> for example 1500, but when change physics mtu to 1600, >> VLAN device's mtu is still 1500. >> Certainly, you can change vlan device's mtu to 1600 manually, >> but I think when you change physics device's mtu, VLAN's mtu should be changed >> automatically instead of by manually. I don't like the idea. It's perfectly valid to have the physical dev with 9000 MTU and have vlans with 1500 MTU. >> Steps to Reproduce: >> 1.vconfig add eth4 3 >> 2.ifconfig eth4 mtu 1600 >> 3.check mtu on eth4.3 >> >> And what's worse is that if you decrease mtu of pyhsical device, >> and when you want to increase it, the mtu of vlan device won't be changed. That *might* be worth fixing, but even so, some NICs might handle that just fine, so my opinion is that this should not change either. Thanks, Ben >> >> Steps to Reproduce: >> 1.vconfig add eth4 3 >> 2.ifconfig eth4 mtu 100 >> 3.ifconfig eth4 mtu 1500 >> 4.the mtu of eth4.3 is still 100 >> >> This bug is reported by Liang Zheng(lzheng@redhat.com). >> >> Signed-off-by: Weiping Pan<panweiping3@gmail.com> >> --- >> net/8021q/vlan.c | 3 --- >> 1 files changed, 0 insertions(+), 3 deletions(-) >> >> diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c >> index 8970ba1..f6072b4 100644 >> --- a/net/8021q/vlan.c >> +++ b/net/8021q/vlan.c >> @@ -417,9 +417,6 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, >> if (!vlandev) >> continue; >> >> - if (vlandev->mtu<= dev->mtu) >> - continue; >> - >> dev_set_mtu(vlandev, dev->mtu); >> } >> break; > > -- > 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 Wed, Oct 19, 2011 at 10:06:48AM +0800, WeipingPan wrote: > > What do you think of this patch ? I think the current behaviour is fine as it is. Cheers,
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 8970ba1..f6072b4 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -417,9 +417,6 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, if (!vlandev) continue; - if (vlandev->mtu <= dev->mtu) - continue; - dev_set_mtu(vlandev, dev->mtu); } break;
Default mtu of vlan device is the same with mtu of physical device, for example 1500, but when change physics mtu to 1600, VLAN device's mtu is still 1500. Certainly, you can change vlan device's mtu to 1600 manually, but I think when you change physics device's mtu, VLAN's mtu should be changed automatically instead of by manually. Steps to Reproduce: 1.vconfig add eth4 3 2.ifconfig eth4 mtu 1600 3.check mtu on eth4.3 And what's worse is that if you decrease mtu of pyhsical device, and when you want to increase it, the mtu of vlan device won't be changed. Steps to Reproduce: 1.vconfig add eth4 3 2.ifconfig eth4 mtu 100 3.ifconfig eth4 mtu 1500 4.the mtu of eth4.3 is still 100 This bug is reported by Liang Zheng(lzheng@redhat.com). Signed-off-by: Weiping Pan <panweiping3@gmail.com> --- net/8021q/vlan.c | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-)