From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Pedro Falcato <pfalcato@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Lorenzo Stoakes <ljs@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>, Jann Horn <jannh@google.com>,
Dev Jain <dev.jain@arm.com>, Luke Yang <luyang@redhat.com>,
jhladky@redhat.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] mm/mprotect: move softleaf code out of the main function
Date: Thu, 19 Mar 2026 22:33:47 +0100 [thread overview]
Message-ID: <f0ccf41d-16ca-404a-bb84-fe038bcfe0b4@kernel.org> (raw)
In-Reply-To: <20260319183108.1105090-3-pfalcato@suse.de>
On 3/19/26 19:31, Pedro Falcato wrote:
> Move softleaf change_pte_range code into a separate function. This makes
> the change_pte_range() function (or where it inlines) a good bit
> smaller. Plus it lessens cognitive load when reading through the
> function.
>
> Signed-off-by: Pedro Falcato <pfalcato@suse.de>
> ---
> mm/mprotect.c | 128 +++++++++++++++++++++++++++-----------------------
> 1 file changed, 68 insertions(+), 60 deletions(-)
>
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 1bd0d4aa07c2..8d4fa38a8a26 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -211,6 +211,73 @@ static void set_write_prot_commit_flush_ptes(struct vm_area_struct *vma,
> commit_anon_folio_batch(vma, folio, page, addr, ptep, oldpte, ptent, nr_ptes, tlb);
> }
>
> +static noinline long change_pte_softleaf(struct vm_area_struct *vma,
Why the noinline? This sounds like something that works good on some
CPUs and bad on others, no?
I like the cleanup, but the noinline really is odd.
> + unsigned long addr, pte_t *pte, pte_t oldpte, unsigned long cp_flags)
I'd call that "change_softleaf_pte"
> +{
> + bool uffd_wp = cp_flags & MM_CP_UFFD_WP;
> + bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE;
both can be const.
> + softleaf_t entry = softleaf_from_pte(oldpte);
> + pte_t newpte;
> +
[...]
--
Cheers,
David
next prev parent reply other threads:[~2026-03-19 21:33 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-19 18:31 [PATCH 0/4] mm/mprotect: micro-optimization work Pedro Falcato
2026-03-19 18:31 ` [PATCH 1/4] mm/mprotect: encourage inlining with __always_inline Pedro Falcato
2026-03-19 18:59 ` Lorenzo Stoakes (Oracle)
2026-03-19 19:00 ` Lorenzo Stoakes (Oracle)
2026-03-19 21:28 ` David Hildenbrand (Arm)
2026-03-20 9:59 ` Pedro Falcato
2026-03-20 10:08 ` David Hildenbrand (Arm)
2026-03-19 18:31 ` [PATCH 2/4] mm/mprotect: move softleaf code out of the main function Pedro Falcato
2026-03-19 19:06 ` Lorenzo Stoakes (Oracle)
2026-03-19 21:33 ` David Hildenbrand (Arm) [this message]
2026-03-20 10:04 ` Pedro Falcato
2026-03-20 10:07 ` David Hildenbrand (Arm)
2026-03-20 10:54 ` Lorenzo Stoakes (Oracle)
2026-03-19 18:31 ` [PATCH 3/4] mm/mprotect: un-inline folio_pte_batch_flags() Pedro Falcato
2026-03-19 19:14 ` Lorenzo Stoakes (Oracle)
2026-03-19 21:41 ` David Hildenbrand (Arm)
2026-03-20 10:36 ` Lorenzo Stoakes (Oracle)
2026-03-20 10:59 ` Pedro Falcato
2026-03-20 11:02 ` David Hildenbrand (Arm)
2026-03-20 11:27 ` Lorenzo Stoakes (Oracle)
2026-03-20 11:01 ` David Hildenbrand (Arm)
2026-03-20 11:45 ` Lorenzo Stoakes (Oracle)
2026-03-23 12:56 ` David Hildenbrand (Arm)
2026-03-20 10:34 ` Pedro Falcato
2026-03-20 10:51 ` Lorenzo Stoakes (Oracle)
2026-03-19 18:31 ` [PATCH 4/4] mm/mprotect: special-case small folios when applying write permissions Pedro Falcato
2026-03-19 19:17 ` Lorenzo Stoakes (Oracle)
2026-03-20 10:36 ` Pedro Falcato
2026-03-20 10:42 ` Lorenzo Stoakes (Oracle)
2026-03-19 21:43 ` David Hildenbrand (Arm)
2026-03-20 10:37 ` Pedro Falcato
2026-03-20 2:42 ` [PATCH 0/4] mm/mprotect: micro-optimization work Andrew Morton
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