Date: Sat, 19 Jun 2010 12:23:44 -0700
From: Jeremy Chadwick <freebsd@jdc.parodius.com>
To: freebsd-stable@freebsd.org
Cc: jfvogel@gmail.com
Subject: RELENG_8 em(4) -- input errors ("Missed Packets")
Message-ID: <20100619192344.GA84784@icarus.home.lan>
next in thread | raw e-mail | index | archive | help
Something I came across today on a RELENG_8 (8.1-PRERELEASE, amd64,
built Jun 8th) system we have:
$ netstat -i -n -d -I em1
Name Mtu Network Address Ipkts Ierrs Idrop Opkts Oerrs Coll Drop
em1 1500 <Link#2> xx:xx:xx:xx:xx:xx 16117371 17 0 11011087 0 0 0
em1 1500 xxxxxxxxx/xx xxxxxxxxxxx 16108452 - - 11024972 - - -
The input errors are what concerned me. I poked dev.em.1.stats and got
the following:
em1: Excessive collisions = 0
em1: Sequence errors = 0
em1: Defer count = 0
em1: Missed Packets = 17
em1: Receive No Buffers = 0
em1: Receive Length Errors = 0
em1: Receive errors = 0
em1: Crc errors = 0
em1: Alignment errors = 0
em1: Collision/Carrier extension errors = 0
em1: watchdog timeouts = 0
em1: XON Rcvd = 0
em1: XON Xmtd = 0
em1: XOFF Rcvd = 0
em1: XOFF Xmtd = 0
em1: Good Packets Rcvd = 16117349
em1: Good Packets Xmtd = 11046837
em1: TSO Contexts Xmtd = 17609
em1: TSO Contexts Failed = 0
What exactly does "Missed Packets" mean here? How is a packet "missed"?
Said port on our switch doesn't any sign of problems:
hp2510g# show interfaces 2
Status and Counters - Port Counters for port 2
Name : port2
Link Status : Up
Totals (Since boot or last clear) :
Bytes Rx : 3,548,949,136 Bytes Tx : 2,613,086,119
Unicast Rx : 182,088,023 Unicast Tx : 255,981,685
Bcast/Mcast Rx : 14,674 Bcast/Mcast Tx : 81,852
Errors (Since boot or last clear) :
FCS Rx : 0 Drops Rx : 0
Alignment Rx : 0 Collisions Tx : 0
Runts Rx : 0 Late Colln Tx : 0
Giants Rx : 0 Excessive Colln : 0
Total Rx Errors : 0 Deferred Tx : 0
Rates (5 minute weighted average) :
Total Rx (bps) : 1457984 Total Tx (bps) : 1494568
Unicast Rx (Pkts/sec) : 0 Unicast Tx (Pkts/sec) : 0
B/Mcast Rx (Pkts/sec) : 0 B/Mcast Tx (Pkts/sec) : 0
Utilization Rx : 00.04 % Utilization Tx : 00.04 %
Relevant userland and kernel stuff:
$ ifconfig em1
em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=219b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,TSO4,WOL_MAGIC>
ether xx:xx:xx:xx:xx:xx
inet xxxxxxxxxxx netmask xxxxxxxxxx broadcast xxxxxxxxxxx
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
$ netstat -m
2162/1678/3840 mbufs in use (current/cache/total)
2048/1030/3078/25600 mbuf clusters in use (current/cache/total/max)
2048/896 mbuf+clusters out of packet secondary zone in use (current/cache)
0/104/104/12800 4k (page size) jumbo clusters in use (current/cache/total/max)
0/0/0/6400 9k jumbo clusters in use (current/cache/total/max)
0/0/0/3200 16k jumbo clusters in use (current/cache/total/max)
4636K/2895K/7532K bytes allocated to network (current/cache/total)
0/0/0 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
0/0/0 requests for jumbo clusters denied (4k/9k/16k)
0/0/0 sfbufs in use (current/peak/max)
0 requests for sfbufs denied
0 requests for sfbufs delayed
0 requests for I/O initiated by sendfile
0 calls to protocol drain routines
$ vmstat -i
interrupt total rate
irq4: uart0 868 0
irq6: fdc0 1 0
irq23: uhci3 ehci1+ 332 0
cpu0: timer 1818467717 2000
irq256: em0 375532 0
irq257: em1 5004095 5
irq258: ahci0 5879898 6
cpu1: timer 1818466783 2000
cpu3: timer 1818466831 2000
cpu2: timer 1818466828 2000
Total 7285128885 8012
$ dmesg | grep em1
em1: <Intel(R) PRO/1000 Network Connection 7.0.5> port 0x3000-0x301f mem 0xd0300000-0xd031ffff irq 17 at device 0.0 on pci15
em1: Using MSI interrupt
em1: [FILTER]
$ pciconf -lvc
em1@pci0:15:0:0: class=0x020000 card=0x109a15d9 chip=0x109a8086 rev=0x00 hdr=0x00
vendor = 'Intel Corporation'
device = 'Intel PRO/1000 PL Network Adaptor (82573L)'
class = network
subclass = ethernet
cap 01[c8] = powerspec 2 supports D0 D3 current D0
cap 05[d0] = MSI supports 1 message, 64 bit enabled with 1 message
cap 10[e0] = PCI-Express 1 endpoint max data 128(256) link x1(x1)
--
| Jeremy Chadwick jdc@parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100619192344.GA84784>