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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47f464c1f84sm8103524f8f.29.2026.07.14.05.34.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Jul 2026 05:34:18 -0700 (PDT) Date: Tue, 14 Jul 2026 13:34:15 +0100 From: David Laight To: Yeoreum Yun Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com, linux-csky@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, david@kernel.org, linux@armlinux.org.uk, akpm@linux-foundation.org, ankur.a.arora@oracle.com, rppt@kernel.org, linmag7@gmail.com, chleroy@kernel.org, klarasmodin@gmail.com, chenhuacai@kernel.org, kernel@xen0n.name, kas@kernel.org, zhangtianyang@loongson.cn, wangyuli@aosc.io, tsbogend@alpha.franken.de, ljs@kernel.org, jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, ryan.roberts@arm.com, pasha.tatashin@soleen.com, rmclure@linux.ibm.com, baolin.wang@linux.alibaba.com, tj@kernel.org, kevin.brodsky@arm.com, anup@brainfault.org, atish.patra@linux.dev, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, hannes@cmpxchg.org, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, kasong@tencent.com, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, vincenzo.frascino@arm.com, anshuman.khandual@arm.com, yang@os.amperecomputing.com, chaitanyas.prakash@arm.com, ardb@kernel.org, guoren@kernel.org, yang.li85200@gmail.com, viro@zeniv.linux.org.uk, dinguyen@kernel.org, schuster.simon@siemens-energy.com, wangruikang@iscas.ac.cn, junhui.liu@pigmoral.tech, muchun.song@linux.dev, vishal.moola@gmail.com, namcao@linutronix.de, pavel@kernel.org, djbw@kernel.org, yu-cheng.yu@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, coxu@redhat.com, andreas@gaisler.com, liam@infradead.org, vbabka@kernel.org, surenb@google.com, mhocko@suse.com, geert@linux-m68k.org, shorne@gmail.com, jonas@southpole.se, stefan.kristiansson@saunalahti.fi Subject: Re: [RFC PATCH 02/34] ARM: mm: make 2-level pgd_t a scalar Message-ID: <20260714133415.78e25654@pumpkin> In-Reply-To: <20260713135614.1618183-3-yeoreum.yun@arm.com> References: <20260713135614.1618183-1-yeoreum.yun@arm.com> <20260713135614.1618183-3-yeoreum.yun@arm.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 4977240002 X-Stat-Signature: a6zk1hs6foi3bd9hy7oeo881yn5nbede X-HE-Tag: 1784032460-19320 X-HE-Meta: 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 zltn7XQm 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 13 Jul 2026 14:55:41 +0100 Yeoreum Yun wrote: > From: "David Hildenbrand (Arm)" > > We don't want pgd_t to be an array, as it prohibits returning it from a > function, like pgdp_get(). If you use a two element structure the compiler/ABI might be able to return that from a function in two registers. That might make the entire mess more readable ... David