Broken kernel compile on 5.1-RELEASE / 5-CURRENT (SMP, PAE & scsi)

[Don Lewis]

On 19 Aug, Mark Sergeant wrote:
> Hi All,
> 
> 	When trying to compile a kernel for my 8 cpu DELL 8450's I recieve an
> extremly puzzling error, I get a bunch of errors when compiling a kernel
> that has the following options in it...
> 
> options     WITNESS
> options     NETSMB
> options     NETSMBCRYPTO
> options     LIBMCHAIN
> options     LIBICONV
> options     PAE
> options     SMP                     
> options     APIC_IO
> 
> Without  PAE SMP or APIC_IO the kernel will compile fine. With these
> options I get the following error when compiling the sym scsi driver.

Take a look at /usr/src/sys/i386/conf/PAE.  It says:

# What follows is a list of drivers that are normally in GENERIC, but either
# don't work or are untested with PAE.  Be very careful before enabling any
# of these drivers.  Drivers which use DMA and don't handle 64 bit physical
# address properly may cause data corruption when used in a machine with more
# than 4 gigabytes of memory.

and under this comment it lists the sym and usb drivers.