irq256 ????

[Josh Carroll]

> I've just found in my machine's vmstat -i output:
>
> irq256: em0                        42054          2

*snip*

> $ dmesg|fgrep em0
> em0: <Intel(R) PRO/1000 Network Connection 6.9.5> port 0x30c0-0x30df
> mem 0x90300000-0x9031ffff,0x90324000-0x90324fff irq 20 at device 25.0 on pci0
> em0: Using MSI interrupt em0: [FILTER]
> em0: Ethernet address: 00:19:d1:25:78:0a
> $ uname -a
> FreeBSD XXX 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #0: Thu Oct  2 21:35:45 CEST 2008
> root at XXX:/usr/obj/usr/src/sys/GENERIC  i386 $
> ====
>
> What's that? (world and kernel are in sync)

For what it's worth, I see the same thing on 7.1-PRERELEASE on a box
with an em0 (PCI card) and on-board PCI-E msk0:

% grep -E '(em0|msk0|mskc0)' /var/run/dmesg.boot
mskc0: <Marvell Yukon 88E8056 Gigabit Ethernet> port 0xc800-0xc8ff mem
0xfe9fc000-0xfe9fffff irq 17 at device 0.0 on pci2
msk0: <Marvell Technology Group Ltd. Yukon EC Ultra Id 0xb4 Rev 0x03> on mskc0
msk0: Ethernet address: 00:1d:60:bc:cc:39
miibus0: <MII bus> on msk0
mskc0: [FILTER]
em0: <Intel(R) PRO/1000 Network Connection 6.9.5> port 0xec00-0xec3f
mem 0xfebe0000-0xfebfffff,0xfebc0000-0xfebdffff irq 17 at device 1.0
on pci5
em0: [FILTER]
em0: Ethernet address: 00:0e:0c:6c:b9:16
em0: link state changed to UP

% vmstat -i
interrupt                          total       rate
irq1: atkbd0                           2          0
irq6: fdc0                            11          0
irq17: em0 atapci1              53621626        108
irq18: uhci2 ehci+                     1          0
irq19: fwohci0+                       10          0
irq22: atapci2                  29345269         59
irq23: uhci3 ehci1                     1          0
cpu0: timer                    991289650       2000
irq256: mskc0                   37714212         76
cpu1: timer                    991279642       2000
cpu2: timer                    991279641       2000
cpu3: timer                    991279641       2000
Total                         4085809706       8243

And despite the "weird" interrupt, msk0 is operating just fine.

Regards,
Josh