On Tue, 23 Jul 2002, Andrew Morton wrote:
> Robert and George's patch doesn't seem to be optimal though - if we're
> not going to preempt at spin_unlock() time, we need to preempt at
> local_irq_restore() time. It'll be untrivial to fix all this, but this
> very subtle change to the locking semantics with CONFIG_PREEMPT is quite
> nasty.
this is precisely the reason why we cannot pretend these bugs do not exist
and just work this around in preempt_schedule(). Code that relies on
cli/sti for atomicity should be pretty rare and limited, there's 1 known
case so far where it leads to bugs.
Ingo
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This archive was generated by hypermail 2b29 : Tue Jul 30 2002 - 14:00:15 EST