David S. Miller wrote:

On Wed, 16 Feb 2005 06:16:45 +0100
Ingo Molnar [off-list ref] wrote:

quoted

Maybe the networking
stack would break if we allowed the TIMER softirq (thread) to preempt
the NET softirq (threads) (and vice versa)?

The major assumption is that softirq's run indivisibly per-cpu.
Otherwise the per-cpu queues of RX and TX packet work would
get corrupted.

For what its worth, I, a short while ago, put together a workqueue package to a) 
allow easy priority setting for work queues and b) change either softirq, 
tasklet or bh code to use workqueues.  This was done mostly with CPP macros and 
a few conversion routines.  I then converted the network code to use this 
package simply by adding a key include to a couple of files.  The result worked 
on UP but ended up hanging the network code on SMP.  Everything else still 
worked, but not the net stuff.  I never ran down the problem as the "boss" was 
not interested in SMP...

George

-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/