Re: TLB and PTE coherency during munmap

[Peter Zijlstra <peterz@infradead.org>]

On Thu, May 30, 2013 at 12:30:51PM +0530, Vineet Gupta wrote:
> On 05/30/2013 12:26 PM, Peter Zijlstra wrote:
> > On Thu, May 30, 2013 at 10:34:53AM +0530, Vineet Gupta wrote:
> >> On 05/29/2013 11:21 PM, Peter Zijlstra wrote:
> >>
> >> BTW, since we are on the topic, it seems that we are missing tlb_fast_mode() in
> >> one spot - unless it is tied to rcu table free stuff.
> >>
> >> -------------->
> >> From: Vineet Gupta <vgupta@synopsys.com>
> >> Date: Thu, 30 May 2013 10:25:30 +0530
> >> Subject: [PATCH] mm: tlb_fast_mode check missing in tlb_finish_mmu()
> >>
> >> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
> >> ---
> >>  mm/memory.c |    3 +++
> >>  1 file changed, 3 insertions(+)
> >>
> >> diff --git a/mm/memory.c b/mm/memory.c
> >> index d9d5fd9..569ffe1 100644
> >> --- a/mm/memory.c
> >> +++ b/mm/memory.c
> >> @@ -269,6 +269,9 @@ void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long
> >> start, unsigned long e
> >>      /* keep the page table cache within bounds */
> >>      check_pgt_cache();
> >>  
> >> +    if (tlb_fast_mode(tlb))
> >> +        return;
> >> +
> >>      for (batch = tlb->local.next; batch; batch = next) {
> >>          next = batch->next;
> >>          free_pages((unsigned long)batch, 0);
> > Yes I think that is possible. It would shrink the code a little when
> > fast_mode was unconditionally 1 -- ie. simple UP ;-).
> 
> Exactly ! Can you please revert with a Reviewed-by/Acked-by so I can formally send
> it over to linux-mm list.

s/revert/reply/?

Acked-by: Peter Zijlstra <peterz@infradead.org>

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