From: Nadav Amit <nadav.amit@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm <linux-mm@kvack.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>, Yu Zhao <yuzhao@google.com>,
Nick Piggin <npiggin@gmail.com>,
x86@kernel.org
Subject: Re: [RESEND PATCH v5 2/3] mm/mprotect: do not flush when not required architecturally
Date: Wed, 23 Mar 2022 15:09:58 -0700 [thread overview]
Message-ID: <7CAC2587-6C39-4286-9DED-5FC8588B5513@gmail.com> (raw)
In-Reply-To: <20220320000719.1533862-3-namit@vmware.com>
> On Mar 19, 2022, at 5:07 PM, Nadav Amit <nadav.amit@gmail.com> wrote:
>
> From: Nadav Amit <namit@vmware.com>
>
> Currently, using mprotect() to unprotect a memory region or uffd to
> unprotect a memory region causes a TLB flush. However, in such cases the
> PTE is often not modified (i.e., remain RO) and therefore not TLB flush
> is needed.
>
> Add an arch-specific pte_needs_flush() which tells whether a TLB flush
> is needed based on the old PTE and the new one. Implement an x86
> pte_needs_flush().
>
> Always flush the TLB when it is architecturally needed even when
> skipping a TLB flush might only result in a spurious page-faults by
> skipping the flush.
Errr.. Sent the wrong version. Will resend with new version number.
next prev parent reply other threads:[~2022-03-23 22:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220320000719.1533862-1-namit@vmware.com>
2022-03-20 0:07 ` Nadav Amit
2022-03-23 22:09 ` Nadav Amit [this message]
2022-03-20 0:07 ` [RESEND PATCH v5 3/3] mm: avoid unnecessary flush on change_huge_pmd() Nadav Amit
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