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Subject: Re: [PATCH 01/13] mm: Update ptep_get_lockless()s comment
From:   Nadav Amit <nadav.amit@gmail.com>
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Date:   Thu, 27 Oct 2022 10:30:11 -0700
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        X86 ML <x86@kernel.org>, Matthew Wilcox <willy@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Andrea Arcangeli <aarcange@redhat.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
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To:     Peter Zijlstra <peterz@infradead.org>
Precedence: bulk

On Oct 27, 2022, at 12:27 AM, Peter Zijlstra <peterz@infradead.org> =
wrote:

>> One alternative may be using mm_tlb_flush_pending() when setting a =
new PTE
>> to check for pending flushes and flushing the TLB if that is the =
case. This
>> is somewhat similar to what ptep_clear_flush() does. Anyhow, I guess =
this
>> might induce some overheads. As noted before, it is possible to track
>> pending TLB flushes in VMA/page-table granularity, with different =
tradeoffs
>> of overheads.
>=20
> Right; I just don't believe in VMAs for this, they're *waaay* to big.

Well, I did it for VMA in an RFC only because I was pushed. I thought =
and do
think that page-table granularity is the right one.=