Re: ahcisata & SPL NOT LOWERED ON EXIT messages

[Nicolas Joly <njoly%pasteur.fr@localhost>]

On Tue, Feb 14, 2012 at 03:17:14PM +0100, Manuel Bouyer wrote:
> On Tue, Feb 14, 2012 at 03:12:03PM +0100, Nicolas Joly wrote:
> > 
> > Hi,
> > 
> > I have an amd64 -current machine (dmesg attached) that frequently spew
> > tons of `SPL NOT LOWERED ON EXIT' message while trying to dump core on
> > kernel panic.
> > 
> > I tracked it to ahcisata driver which has 2 panic(9) calls inside
> > splbio/splx block (ahci_exec_command() and ahci_atapi_scsipi_request()
> > functions). When panicing, the splx call is indeed missed ...
> 
> I don't understand why panicing without lowering the IPL would
> be an issue. There are even cases where you can't avoid it (e.g.
> when in interrupt context). I don't think the problem is in the ahci
> driver.

I see no problem with the panic call itself. With ddb.onpanic=1, i can
do common operations (without disk access) with no problem. Messages
start firing when the system start using the disks behind the ahcisata
controller to dump core.

-- 
Nicolas Joly

Projects and Developments in Bioinformatics
Institut Pasteur, Paris.