Re: [patch 001/163] mm/memory.c: avoid access flag update TLB flush for retried page fault

Linus Torvalds
2020-08-10T18:57:55Z

On Mon, Aug 10, 2020 at 10:48 AM Yang Shi <shy828301@gmail.com> wrote:
>
> It looks the retried fault still flush TLB with this change.
>
> Shouldn't we do something like this to skip spurious TLB flush:

I have no idea what code-base you're basing your patches against, and
what you're comparing my patch.

Your patch does *exactly* the same thing mine did. Except it does a
"goto unlock" to jump over the flush_tlb_fix_spurious_fault(), while
my pseudo-patch just changed the

if (vmf->flags & FAULT_FLAG_WRITE)

to be a

if (vmf->flags & (FAULT_FLAG_WRITE | FAULT_FLAG_TRIED))

but it has the same effect: it skips the flush_tlb_fix_spurious_fault().

So if you think your patch does something else, then your source code
doesn't match mine. The *only* thing you jumped over was that same
thing that I disabled.

Somebody is confused.

Linus