Message ID | 20090525.103334.68564567.saito@densan.co.jp (mailing list archive) |
---|---|
State | Accepted, archived |
Headers | show |
On Mon, 2009-05-25 at 10:33 +0900, Hideo Saito wrote: > > This report came from LKML, although I should post it here first, > the report said that there is a regression in linux-2.6.29 as to > flushing a TLB entry that was going to be re-used when a context > overflowed from the TLB. > > On Fri, May 22, 2009 at 6:27 PM, Benjamin Herrenschmidt wrote: > > Have you verified that this change fixes your problem ? > > I tested using "hackbench 100" and it was done successfully on my > platform with e500(MPC8548). > > > > > Can you re-submit to linuxppc-dev@ozlabs.org mailing list, along > with > > proper changeset comment and signed-off-by: line ? > > I am sorry I don't know as to the proper changeset comment. > Well, that simply means a proper description of the bug and the fix :-) I'll cook up one. Cheers, Ben.
--- arch/powerpc/mm/mmu_context_nohash.c.orig 2009-03-24 08:12:14.000000000 +0900 +++ arch/powerpc/mm/mmu_context_nohash.c 2009-05-20 18:33:53.000000000 +0900 @@ -122,22 +122,22 @@ static unsigned int steal_context_up(uns struct mm_struct *mm; int cpu = smp_processor_id(); /* Pick up the victim mm */ mm = context_mm[id]; pr_debug("[%d] steal context %d from mm @%p\n", cpu, id, mm); - /* Mark this mm has having no context anymore */ - mm->context.id = MMU_NO_CONTEXT; - /* Flush the TLB for that context */ local_flush_tlb_mm(mm); + /* Mark this mm has having no context anymore */ + mm->context.id = MMU_NO_CONTEXT; + /* XXX This clear should ultimately be part of local_flush_tlb_mm */ __clear_bit(id, stale_map[cpu]); return id; } #ifdef DEBUG_MAP_CONSISTENCY static void context_check_map(void)