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Mon, 21 Jul 2025 04:52:02 -0700 (PDT) From: wang lian To: richard.weiyang@gmail.com Cc: Liam.Howlett@oracle.com, akpm@linux-foundation.org, brauner@kernel.org, broonie@kernel.org, david@redhat.com, gkwang@linx-info.com, jannh@google.com, lianux.mm@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, ludovico.zy.wu@gmail.com, p1ucky0923@gmail.com, ryncsn@gmail.com, shuah@kernel.org, sj@kernel.org, vbabka@suse.cz, zijing.zhang@proton.me, ziy@nvidia.com Subject: Re: [PATCH 1/2] selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" Date: Mon, 21 Jul 2025 19:51:49 +0800 Message-ID: <20250721115149.42755-1-lianux.mm@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250718000835.65qaxtwfgwborgls@master> References: <20250718000835.65qaxtwfgwborgls@master> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: BBE6BA0002 X-Stat-Signature: dd16p5k7516wqgjyzffey4wjihayz3un X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1753098723-346244 X-HE-Meta: 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 QHUem4LM 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > 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 Thanks! > -- > Wei Yang > Help you, Help me Best regards, Wang Lian