request for MFC of em/igb drivers

[Eugene Grosbein]

On 17.11.2010 13:04, Chris Peiffer wrote:
> 
> Hi,
> 
> I've been watching the traffic here over the last few months relating
> to the em and igb Intel ethernet drivers. It seems like there's a big
> consensus that HEAD has some good new fixes.
> 
> Looking at this:
> 
> http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/dev/e1000/if_em.c
> 
> There's a pretty big commit to HEAD in rev 1.58 on Sep 27 that's
> marked "MFC: a week" but it doesn't look like anything's been MFC'd
> since. (And several other revisions that look more experimental have
> since gone into HEAD.) 
> 
> We've been seeing some weird issues with em devices under high load
> and if these changes in 1.58 are ready for STABLE we'd love to test
> them live.
> 
> So this is a beg... if the relevant committers are out here, can that
> MFC go through soon? Or if it can't, or I'm reading the logs wrong,
> please explain. 
> 
> Thanks in advance.

Indeed, in RELENG_8 em(4) is not useable for us because of two flaws:

1. It panices system due to NULL pointers dereference.
It needs the following patch taken from CURRENT's igb(4):

--- if_em.c.orig        2010-11-02 15:45:56.000000000 +0600
+++ if_em.c     2010-11-08 14:24:46.000000000 +0600
@@ -4181,9 +4181,11 @@
                        ifp->if_ierrors++;
                        /* Reuse loaded DMA map and just update mbuf chain */
                        mp = rxr->rx_buffers[i].m_head;
+                       if(mp) {
                        mp->m_len = mp->m_pkthdr.len = MCLBYTES;
                        mp->m_data = mp->m_ext.ext_buf;
                        mp->m_next = NULL;
+                       }
                        if (adapter->max_frame_size <=
                            (MCLBYTES - ETHER_ALIGN))
                                m_adj(mp, ETHER_ALIGN);

igb(4) in RELENG_8 has not this fix too and there is a PR:
http://www.freebsd.org/cgi/query-pr.cgi?pr=150920

2. It makes physical link down/up for every vlan creation/deletion
that leads to 3 seconds of service interruption and
down/up events for all other vlans based on same parent interface.
It needs the following patch that's already present in CURRENT
but not in RELENG_8:

@@ -4342,7 +4344,8 @@
        em_shadow_vfta[index] |= (1 << bit);
        ++adapter->num_vlans;
        /* Re-init to load the changes */
-       em_init(adapter);
+       if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
+               em_init(adapter);
 }
 
 /*
@@ -4366,7 +4369,8 @@
        em_shadow_vfta[index] &= ~(1 << bit);
        --adapter->num_vlans;
        /* Re-init to load the changes */
-       em_init(adapter);
+       if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
+               em_init(adapter);
 }

 static void