dmesg and GIANT-LOCK

[James Long]

On Tue, Mar 13, 2007 at 01:50:34PM -0400, Kris Kennaway wrote:
> On Tue, Mar 13, 2007 at 01:06:12AM -0700, James Long wrote:
> > With regard to the recent thread about looking for GIANT-LOCKs in
> > dmesg, why would one system say:
> > 
> > ns : 00:56:29 /home/james> uname -v ;dmesg | grep fxp
> > FreeBSD 6.2-STABLE #0: Tue Feb 20 15:47:09 PST 2007
> > fxp0: <Intel 82559 Pro/100 Ethernet> port 0x2400-0x243f mem 0xc4fff000-0xc4ffffff,0xc4e00000-0xc4efffff irq 10 at device 2.0 on pci0
> > miibus0: <MII bus> on fxp0
> > fxp0: Ethernet address: 00:02:a5:0a:57:73
> > 
> > 
> > while a more recent build says:
> > 
> > t30 : 00:56:19 /home/james> uname -v ;dmesg | grep fxp
> > FreeBSD 6.2-STABLE #2: Thu Mar  8 08:23:11 PST 2007
> > fxp0: <Intel 82801CAM (ICH3) Pro/100 VE Ethernet> port 0x7400-0x743f mem 0xd0200000-0xd0200fff irq 11 at device 8.0 on pci2
> > miibus0: <MII bus> on fxp0
> > fxp0: Ethernet address: 00:09:6b:86:82:a6
> > fxp0: [GIANT-LOCKED]
> 
> fxp is not giant locked, you can check the source for the INTR_MPSAFE
> flag in sys/dev/fxp/if_fxp.c.  I'm not sure how you are seeing this,
> please describe the configuration of this system further (kernel
> config, loader.conf).
> 
> Kris

It just dawned on me when you said "INTR_MPSAFE", would having

options	IPSEC

in the kernel config cause fxp to use GIANT?

dmesg says in part:

FreeBSD 6.2-STABLE #2: Thu Mar  8 08:23:11 PST 2007
    root at t30.museum.rain.com:/usr/obj/usr/src/sys/T30
WARNING: debug.mpsafenet forced to 0 as ipsec requires Giant
WARNING: MPSAFE network stack disabled, expect reduced performance.