Subject: Re: SMP re-entrancy in kernel drivers/"bottom half?"
To: Jason Thorpe <>
From: Jonathan Stone <>
List: tech-kern
Date: 12/17/2003 19:31:08
>> [...] we want finer-grained locks, not yet more
>> use of kernel_lock.
>Yes, we do, but I don't think IPL_*_slock is the way to get it.

In the long term, no of course not.  I dont have the energy or time
right now to drop a spinlock into every pcb, *and* get the hash-table
references right too. But thats clearly the next logical step.

The reason I sugested for IPL_*_slock is: it means one smp-safe
interrupt routine at each IPL level can reach outward simultaneously,
instead of totally serialising all SMP-safe interrupt routines anytime
they start reaching outside the softc: one NIC interrupt routine *and*
one disk interrupt routine can touch non-softc stuff simultaneously,
instead of in serial.

Hey, I thought you'd *like* that :-/.

That aside, though: do you see any showstoppers?