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[2003:dc:6f1d:f00:230:64ff:fe74:809]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b01902d0e99sm541005766b.12.2025.09.01.02.19.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Sep 2025 02:19:40 -0700 (PDT) From: Max Kellermann To: akpm@linux-foundation.org, david@redhat.com, axelrasmussen@google.com, yuanchu@google.com, willy@infradead.org, hughd@google.com, mhocko@suse.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, vishal.moola@gmail.com, linux@armlinux.org.uk, James.Bottomley@HansenPartnership.com, deller@gmx.de, agordeev@linux.ibm.com, gerald.schaefer@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, davem@davemloft.net, andreas@gaisler.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, chris@zankel.net, jcmvbkbc@gmail.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, weixugc@google.com, baolin.wang@linux.alibaba.com, rientjes@google.com, shakeel.butt@linux.dev, max.kellermann@ionos.com, thuth@redhat.com, broonie@kernel.org, osalvador@suse.de, jfalempe@redhat.com, mpe@ellerman.id.au, nysal@linux.ibm.com, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v4 09/12] mm/mm_types: add const to pointer parameters for improved const-correctness Date: Mon, 1 Sep 2025 11:19:12 +0200 Message-ID: <20250901091916.3002082-10-max.kellermann@ionos.com> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250901091916.3002082-1-max.kellermann@ionos.com> References: <20250901091916.3002082-1-max.kellermann@ionos.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The memory management (mm) subsystem is a fundamental low-level component of the Linux kernel. Establishing const-correctness at this foundational level enables higher-level subsystems, such as filesystems and drivers, to also adopt const-correctness in their interfaces. This patch lays the groundwork for broader const-correctness throughout the kernel by starting with the core mm subsystem. This patch adds const qualifiers to ptdesc and folio pointer parameters in mm_types.h functions that do not modify the referenced memory, improving type safety and enabling compiler optimizations. Functions improved: - ptdesc_pmd_pts_count() - folio_get_private() Signed-off-by: Max Kellermann Reviewed-by: Vishal Moola (Oracle) --- include/linux/mm_types.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index d934a3a5b443..46e27ee14bcf 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -632,7 +632,7 @@ static inline void ptdesc_pmd_pts_dec(struct ptdesc *pt= desc) atomic_dec(&ptdesc->pt_share_count); } =20 -static inline int ptdesc_pmd_pts_count(struct ptdesc *ptdesc) +static inline int ptdesc_pmd_pts_count(const struct ptdesc *const ptdesc) { return atomic_read(&ptdesc->pt_share_count); } @@ -660,7 +660,7 @@ static inline void set_page_private(struct page *page, = unsigned long private) page->private =3D private; } =20 -static inline void *folio_get_private(struct folio *folio) +static inline void *folio_get_private(const struct folio *const folio) { return folio->private; } --=20 2.47.2