> I sometimes heard that wm had some problems with jumbo MTU, but I've > never checked whether it really has a bug or not. I suspect the bug > is not in NFS stack but in wm.
Based on diffing tcpdump -x output, if there is such a bug it is in udp4csum offload. I consider this unlikely because I think I tried it with all offloading turned off. Of course, it's also possible tcpdump isn't showing the full truth.... I should be able to create a test setup I can play with freely, so I ought to be able to test this theory relatively painlessly - though if it's specific to the details of the chip, my test setup may not misbehave. I also have access to some machines with bge instead of wm, so I should be able to test with bge instead of wm in any of the four combinations ({bge,wm} on NFS {server,client}). > I don't use jumbo MTU, so usually don't test the function when I add > the support of a new chip. Sorry :( In case it helps, the case I saw issues with has wm1 at pci7 dev 8 function 0: Intel i82541GI 1000BASE-T Ethernet, rev. 5 wm1: interrupting at ioapic2 pin 1 (irq 3) wm1: 32-bit 66MHz PCI bus wm1: 65536 word (16 address bits) SPI EEPROM wm1: Ethernet address 00:13:72:4d:83:03 igphy1 at wm1 phy 1: Intel IGP01E1000 Gigabit PHY, rev. 0 igphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto ukphy1 at wm1 phy 2: Generic IEEE 802.3u media interface ukphy1: OUI 0x000000, model 0x0000, rev. 0 ukphy1: no media present on the NFS client and wm0 at pci0 dev 10 function 0: Intel i82541PI 1000BASE-T Ethernet, rev. 5 wm0: interrupting at irq 12 wm0: 32-bit 33MHz PCI bus wm0: 64 word (6 address bits) MicroWire EEPROM wm0: Ethernet address 90:e2:ba:3b:f5:54 igphy0 at wm0 phy 1: Intel IGP01E1000 Gigabit PHY, rev. 0 igphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto on the NFS server. I can show more details, up to and including full boot-time autoconf messages, if that would help. wm0 on the NFS server is an add-on PCI card; wm1 on the NFS client is onboard. I don't know whether the cable between them is straight or crossover. (I also don't know whether that's relevant; I don't know enough about how gigabit auto-x negotation works.) /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B