Re: [PATCH v6 2/4] mm/memory.c: Update local TLB if PTE entry exists

[Andrew Morton]

On Mon, 25 May 2020 10:52:38 +0800 Bibo Mao <maobibo@xxxxxxxxxxx> wrote:

> If two threads concurrently fault at the same page, the thread that
> won the race updates the PTE and its local TLB. For now, the other
> thread gives up, simply does nothing, and continues.
> 
> It could happen that this second thread triggers another fault, whereby
> it only updates its local TLB while handling the fault. Instead of
> triggering another fault, let's directly update the local TLB of the
> second thread. Function update_mmu_tlb is used here to update local
> TLB on the second thread, and it is defined as empty on other arches.

Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

Thanks for persisting with these.