From nobody Mon Feb 9 17:07:42 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1930542A97 for ; Mon, 7 Apr 2025 09:24:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744017850; cv=none; b=pVu7qYcW2MCFAtYe7NiUjzIZr2+EIuuhrrpMjYpa15bUnPhMpm61O5DY6K7Y1NEelk18qAIu5LCjkJMqIEkV3AI9KVRdctl1dcHBkVXmkoI+C5mcBtoIbwRtFDzxMqAy7CwmmGCNc69K6TPeU+241xaDWrn6Rj3JDkcZvrPY65U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744017850; c=relaxed/simple; bh=gq1Xj/M3orWe8oAAO6fD3x0IRJTeENqeec0izr4rszg=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=bmsGAzuAST+LH6JbBNeplZVOfqJa96HQb5syHFrDMIQzpYmPNj5nTjDfdXZimX7Dar9Xy80ZwKBTY5UnvlxFLRHAoVg1yO6oBOAnCLUWjYgKMG/EEYVMVbNqc1AIt4tbcl0ZUK+th1ZHIVP134KTFDKNsxLBWJPKbYf8sVHnGjg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=d3JbWkbc; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="d3JbWkbc" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=8TN9/ 6BnKvyU3e8vS2iprMvt0bdbH7kVE3wStXcniB4=; b=d3JbWkbc94Y9e0M1/KoJZ kJCyNIX5hYPPv5KEDfpgU49ogkrXWuQDHG99CC1liP2oR3dx8/IgApfkGGeUbeDF n7xib3tanF2iFbJPf+/cjXtxJqYpwkjKpUT6vn+EejgVSGa8fgxK9zigJF+vNWNF IrkHR5+Jej5uuiiwHABwNg= Received: from localhost (unknown []) by gzga-smtp-mtada-g1-2 (Coremail) with SMTP id _____wDn32p6mfNne6pOEw--.1721S2; Mon, 07 Apr 2025 17:23:06 +0800 (CST) From: Xavier To: catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, baohua@kernel.org, ryan.roberts@arm.com, ioworker0@gmail.com Cc: xavier_qy@163.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] mm/contpte: Optimize loop to reduce redundant operations Date: Mon, 7 Apr 2025 17:22:43 +0800 Message-Id: <20250407092243.2207837-1-xavier_qy@163.com> X-Mailer: git-send-email 2.34.1 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 X-CM-TRANSID: _____wDn32p6mfNne6pOEw--.1721S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrur43Cr17tw15uF4xZry7KFg_yoWkArb_Zr 4xtasxXF1UJFyjgFyUt398Gryjgayj93W3JFn29r1UXryfW3yfXrZ2qF92gF1xWrWagr45 trn8Jr13uFnrCjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7sRNE_MDUUUUU== X-CM-SenderInfo: 50dyxvpubt5qqrwthudrp/1tbiTh8oEGfzkOnw9AABsB Content-Type: text/plain; charset="utf-8" This commit optimizes the contpte_ptep_get function by adding early termination logic. It checks if the dirty and young bits of orig_pte are already set and skips redundant bit-setting operations during the loop. This reduces unnecessary iterations and improves performance. Signed-off-by: Xavier --- arch/arm64/mm/contpte.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c index bcac4f55f9c1..ca15d8f52d14 100644 --- a/arch/arm64/mm/contpte.c +++ b/arch/arm64/mm/contpte.c @@ -163,17 +163,26 @@ pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte) =20 pte_t pte; int i; + bool dirty =3D false; + bool young =3D false; =20 ptep =3D contpte_align_down(ptep); =20 for (i =3D 0; i < CONT_PTES; i++, ptep++) { pte =3D __ptep_get(ptep); =20 - if (pte_dirty(pte)) + if (!dirty && pte_dirty(pte)) { + dirty =3D true; orig_pte =3D pte_mkdirty(orig_pte); + } =20 - if (pte_young(pte)) + if (!young && pte_young(pte)) { + young =3D true; orig_pte =3D pte_mkyoung(orig_pte); + } + + if (dirty && young) + break; } =20 return orig_pte; --=20 2.34.1