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X-IronPort-AV: E=McAfee;i="6600,9927,11010"; a="5112975" X-IronPort-AV: E=Sophos;i="6.07,118,1708416000"; d="scan'208";a="5112975" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 01:05:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,118,1708416000"; d="scan'208";a="34631465" Received: from qzhang4-desk.sh.intel.com (HELO localhost) ([10.239.147.49]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 01:05:24 -0700 From: Qiang Zhang To: Andrew Morton , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, Qiang Zhang , Stable@vger.kernel.org Subject: [PATCH] memtest: use {READ,WRITE}_ONCE in memory scanning Date: Tue, 12 Mar 2024 16:04:23 +0800 Message-Id: <20240312080422.691222-1-qiang4.zhang@intel.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 15A3880012 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: aq66i5wcct65ctcjgax5ph5n7aq4ozbs X-HE-Tag: 1710230728-574675 X-HE-Meta: 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 TqOSZQf+ yMm+W5WIRHuNaOPZvKZaQm09GHkAhqSMm955F2CExV3mXyLfjzLeIiVEnMNO0a9WiXM0Sc5Yi8k77L340vpKK3noFD/XB/85ctFo7kAjmMa2coNZtEZWA7yiDRt7JgvcUx6queQw8Oqwh9l9+yT040ja1hDjlQXoMwbIr/T5bibTjpC+i7Jv1btkLQWZvL7pyUNLPR7kv0Lwh9FGwO8xd9TmIXw4eWzjHtsHLpoNYGn3KNz/39SzicRtflgZ9Bx6RJMCYX5KZ2I96cskc3viC8H0XDzZ1+uM22WDBCs7KyZ0OqP9ZbCHC90JyB8GarjwjY/kPItfXq+0Y2CCJIrlaHDwJP4B/qnqSJALl/RCtenLyoGV/fb3KSBpCjB2RM01xzam31nmkPCrQAn0uB9C0bLdb8nJ3ZQs8vHGz6Ay3PXpXgD3g8JleWBqrnQ== 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: memtest failed to find bad memory when compiled with clang. So use {WRITE,READ}_ONCE to access memory to avoid compiler over optimization. Cc: Signed-off-by: Qiang Zhang --- mm/memtest.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/memtest.c b/mm/memtest.c index 32f3e9dda837..c2c609c39119 100644 --- a/mm/memtest.c +++ b/mm/memtest.c @@ -51,10 +51,10 @@ static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size last_bad = 0; for (p = start; p < end; p++) - *p = pattern; + WRITE_ONCE(*p, pattern); for (p = start; p < end; p++, start_phys_aligned += incr) { - if (*p == pattern) + if (READ_ONCE(*p) == pattern) continue; if (start_phys_aligned == last_bad + incr) { last_bad += incr; -- 2.39.2