On Sat, 19 Jul 2008, Benjamin Herrenschmidt wrote: > > > 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. > > BTW. Is the pte_lock also not a real spinlock anymore ? That may break > other assumptions the powerpc mm code is doing. > > This -rt stuff is just too scary, it changes some fundamental semantics > of the spinlocks. yuck. There's lots of semantics that are changed with -rt that should make everything still work ;-) Some spinlocks remain real spinlocks, but we shouldn't have a problem with most being mutexes. There's some cases that uses per CPU variables or other per cpu actions that require a special CPU_LOCK that protects the data in a preemption mode. The slab.c code in -rt handles this. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
