Re: [PATCH][RT][PPC64] Fix preempt unsafe paths accessing per_cpu variables

Hi Benjamin

* Benjamin Herrenschmidt [off-list ref] [2008-07-19 08:05:30]:

quoted

With the original patch, the pending batch does get flushed 
in a non-preemptable region. 
I am resending the original with just adding the necesary comments.

Your comment isn't what I meant. What I meant is that if the process
is context switched while walking the page tables, the low level powerpc
context switch code should also perform a ???__flush_tlb_pending.

Sorry, I misunderstood.
The powerpc context switch code does perform a __flush_tlb_pending.
Here is the patch 
http://marc.info/?l=linux-kernel&m=119752629222720&w=2

BTW. Is the pte_lock also not a real spinlock anymore ? That may break
other assumptions the powerpc mm code is doing.

pte_lock is a not a real spinlock anymore.

This -rt stuff is just too scary, it changes some fundamental semantics
of the spinlocks. yuck.

Ben.