From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 145F947F4A for ; Tue, 24 Jun 2025 21:15:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750799755; cv=none; b=pEZag4lMyvfpbPWqFdkTEF42eAJT/RXy4512WbBZJGnqDq/uB0sY1M/EwrKVGprGfgLxHN5JvRBqK92bzoVFhfiV+XjAUxwWyH6RSv4L4DXNqBr6YiEaHCu0b87+hyXMK4meri7/TpeqJ3aYbjfFkfmhFDjcjAdZ85gSVWQr+bQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750799755; c=relaxed/simple; bh=W5s1IFYyVhSSY9SrWIviBul/iZkSfkZeODC+rQMFddc=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=j2vMGyFvoHpmGdFIhhZKmQ0zz4BVQ09Qh16lnhn73XDzcWQ2L/g8aVjuOjTltU80mEuX92qf1ROqfV0IfyjOslpaFFzbLDaI3QDTz9zK2E1kbxZz9kG5QQSNIckBrwNezUuQbT6QzBM274F/szxH7kTvZMfaglnrk5iDe3ZiKdE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=2Xj89RYb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="2Xj89RYb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D244C4CEEF; Tue, 24 Jun 2025 21:15:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1750799754; bh=W5s1IFYyVhSSY9SrWIviBul/iZkSfkZeODC+rQMFddc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=2Xj89RYbZEENGcDHm4sbgJ/U8audnpKjKK6tmNfMxq92zVbw7ZNWkizFpNIzlaQ82 UEmLaCiaqjrnDqRPamVI5YPwQVJ0H45/YECUiYSXn/+ED4VWhHFTWSE4anr6ZZ7hDZ Hd4IARd52a5ZB1htmQr1x24Kzxn+z/Ud9DjEd180= Date: Tue, 24 Jun 2025 14:15:53 -0700 From: Andrew Morton To: Xavier Xia Cc: ryan.roberts@arm.com, will@kernel.org, 21cnbao@gmail.com, ioworker0@gmail.com, dev.jain@arm.com, catalin.marinas@arm.com, david@redhat.com, gshan@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, willy@infradead.org, xavier_qy@163.com, ziy@nvidia.com, Barry Song Subject: Re: [PATCH v7] arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get Message-Id: <20250624141553.17afe765c0f692b7a7ec007a@linux-foundation.org> In-Reply-To: <20250624152549.2647828-1-xavier.qyxia@gmail.com> References: <20250624152549.2647828-1-xavier.qyxia@gmail.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Tue, 24 Jun 2025 23:25:49 +0800 Xavier Xia wrote: > This commit optimizes the contpte_ptep_get and contpte_ptep_get_lockless > 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. Thanks, I added this to mm.git for some testing. But perhaps the ARM tree would be a better merge path - more testing, at least.