Re: PANIC: blockable slep lock (sx) msi _at_ ....msi.c:374

On Saturday 05 May 2007 12:01:56 am Attilio Rao wrote:
> John Baldwin wrote:
> > On Friday 04 May 2007 10:53:27 pm Attilio Rao wrote:
> >> Harald Schmalzbauer wrote:
> >>> Hello,
> >>>
> >>> recent changes (during the last 2 days,I guess tha acpi stuff) broke 
> >>> -current for me:
> >>>
> >>> ad6: 476940MB <WDC WD5000KS-07MNB0 07.02E07> at ata3-master SATA300
> >>> SMP: AP CPU #1 Launched!
> >>> panic: blockable sleep lock (sx) msi _at_ 
> >>> /FlashBSD/src/sys/i386/i386/msi.c:374
> >>> cpuid = 0
> >>> KDB: enter: panic
> >>> [thread pid 0 tid 0 ]
> >>> Stopped at      kdb_enter+0x30: leave
> >>> db> bt
> >>> Tracing pid 0 tid 0 td 0xc07c2d60
> >>> kdb_enter(c07422df,0,c0746e47,c1420bdc,c07c2d60,...) at kdb_enter+0x30
> >>> panic(c0746e47,c073180d,c0732bb2,c0764c8e,176,...) at panic+0x135
> >>> witness_checkorder(c082f0fc,1,c0764c8e,176,c55c0980,...) at 
> >>> witness_checkorder+0xd6
> >>> _sx_slock(c082f0fc,c0764c8e,176,c1420c64,c06f7e65,...) at _sx_slock+0x5f
> >>> msi_map(100,c1420d08,c1420d04,c1420c94,c04b5cc5,...) at msi_map+0x22
> >>> nexus_map_msi(c5552000,c55e4000,100,c1420d08,c1420d04,...) at 
> >>> nexus_map_msi+0x1f
> >>> pcib_map_msi(c55d9080,c55e4000,100,c1420d08,c1420d04,...) at 
> >>> pcib_map_msi+0x86
> >>> pcib_map_msi(c55e4200,c55e4000,100,c1420d08,c1420d04,...) at 
> >>> pcib_map_msi+0x86
> >>> pci_remap_msi_irq(c55e4000,100,c06ecb73,c54fff78,100,...) at 
> >>> pci_remap_msi_irq+0xeb
> >>> msi_assign_cpu(c55e6240,0,100,c079d170,c1420d70,...) at 
> > msi_assign_cpu+0x68
> >>> intr_assign_next_cpu(c55e6240,0,c07631d3,1c7,c54f3a44,...) at 
> >>> intr_assign_next_cpu+0x23
> >>> intr_shuffle_irqs(0,141e000,141ec00,141e000,0,...) at 
> >>> intr_shuffle_irqs+0x5e
> >>> mi_startup() at mi_startup+0xa0
> >>> begin() at begin+0x2c
> >> In this case the culprit is intr_table_lock spinlock I think.
> >> This can be fixed switching the msi lock to be a spinlock instead than a 
> >> sx lock.
> > 
> > Actually, I think the real fix is I need to better handle the locking for 
> > assigning interrupts to CPUs.
> 
> I have a question.
> Why you currently use a sx lock? There are places where msi functions 
> can sleep?

malloc M_WAITOK, and considering how rarely this stuff is called (just during 
attach routines for drivers during boot) I didn't consider it important 
enough to do something more complicated.

-- 
John Baldwin