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Thu, 17 Jul 2025 17:08:36 -0700 (PDT) Date: Fri, 18 Jul 2025 00:08:35 +0000 From: Wei Yang To: wang lian Cc: akpm@linux-foundation.org, broonie@kernel.org, david@redhat.com, lorenzo.stoakes@oracle.com, sj@kernel.org, ziy@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, brauner@kernel.org, gkwang@linx-info.com, jannh@google.com, Liam.Howlett@oracle.com, ludovico.zy.wu@gmail.com, p1ucky0923@gmail.com, richard.weiyang@gmail.com, ryncsn@gmail.com, shuah@kernel.org, vbabka@suse.cz, zijing.zhang@proton.me Subject: Re: [PATCH 1/2] selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" Message-ID: <20250718000835.65qaxtwfgwborgls@master> Reply-To: Wei Yang References: <20250717131857.59909-1-lianux.mm@gmail.com> <20250717131857.59909-2-lianux.mm@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250717131857.59909-2-lianux.mm@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) On Thu, Jul 17, 2025 at 09:18:56PM +0800, wang lian wrote: >Several mm selftests use the `asm volatile("" : "+r" (variable));` >construct to force a read of a variable, preventing the compiler from >optimizing away the memory access. This idiom is cryptic and duplicated >across multiple test files. > >Following a suggestion from David[1], this patch refactors this >common pattern into a FORCE_READ() macro > >[1] https://lore.kernel.org/lkml/4a3e0759-caa1-4cfa-bc3f-402593f1eee3@redhat.com/ > >Signed-off-by: wang lian >Reviewed-by: Lorenzo Stoakes Reviewed-by: Wei Yang -- Wei Yang Help you, Help me