Messages in this thread | | | Date | Thu, 23 Aug 2018 14:40:41 +0100 | From | Will Deacon <> | Subject | Re: [PATCH 2/4] mm/tlb: Remove tlb_remove_table() non-concurrent condition |
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On Wed, Aug 22, 2018 at 05:30:14PM +0200, Peter Zijlstra wrote: > Will noted that only checking mm_users is incorrect; we should also > check mm_count in order to cover CPUs that have a lazy reference to > this mm (and could do speculative TLB operations). > > If removing this turns out to be a performance issue, we can > re-instate a more complete check, but in tlb_table_flush() eliding the > call_rcu_sched(). > > Cc: stable@kernel.org > Cc: Nicholas Piggin <npiggin@gmail.com> > Cc: David Miller <davem@davemloft.net> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Fixes: 267239116987 ("mm, powerpc: move the RCU page-table freeing into generic code") > Reported-by: Will Deacon <will.deacon@arm.com> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > --- > mm/memory.c | 9 --------- > 1 file changed, 9 deletions(-)
Acked-by: Will Deacon <will.deacon@arm.com>
Cheers,
Will
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