From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 59BCA1F8753 for ; Tue, 6 May 2025 10:22:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746526969; cv=none; b=ZddoI7i/mkIp778XMt9fBXs/RPmA20/3OO8TKibG7rr2NTP13+Ws5C0yHXi4ej3WRDmS7La01QD5z1JIdhOiW1q9mt+GBMPNB1/AFv4mYFrg0JixBLN9sgTy0hJEhtuKwdIUumXXDwJ583HcC2iT9cR+/B6sWwZtz1/lyX7RfhI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746526969; c=relaxed/simple; bh=DUz8cgfAij/6+9pbRXpcnooNjfeQS+0aVub5YN0Zc/M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Vzq7kx8AzFJJLyKTOjss+0vLKF8Gw54tcLH6zlXyz4ZAFrwpwcmsSHq9gp51shUBJ4Zk/Yyh6Bu8R82PFtY4rRlJR6D3qqkaM9pEqZYbVhROV5zNh3T3xRAH9ompEgbMFYUXp5+pUqB5aI4pUEmKUlRsNNkWmoSZ567wPZUd/5A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 046AE113E; Tue, 6 May 2025 03:22:38 -0700 (PDT) Received: from [10.162.43.13] (K4MQJ0H1H2.blr.arm.com [10.162.43.13]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1F2883F5A1; Tue, 6 May 2025 03:22:41 -0700 (PDT) Message-ID: Date: Tue, 6 May 2025 15:52:39 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/3] Optimize mremap() by PTE-batching To: Anshuman Khandual , akpm@linux-foundation.org Cc: Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, pfalcato@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, david@redhat.com, peterx@redhat.com, ryan.roberts@arm.com, mingo@kernel.org, libang.li@antgroup.com, maobibo@loongson.cn, zhengqi.arch@bytedance.com, baohua@kernel.org, willy@infradead.org, ioworker0@gmail.com, yang@os.amperecomputing.com References: <20250506050056.59250-1-dev.jain@arm.com> Content-Language: en-US From: Dev Jain In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 06/05/25 2:46 pm, Anshuman Khandual wrote: > On 5/6/25 10:30, Dev Jain wrote: >> Use PTE batching to optimize mremap(). >> >> Mapping 512K of memory, memsetting it, remapping it to src + 512K, and >> munmapping it 10,000 times, the average execution time reduces from 1.9 to >> 1.2 seconds, giving a 37% performance optimization. (Apple M3) > > That's impressive improvement. But could you please re-organize the test > description into a pseudo code format or better provide the test program > itself (which should be compact anyways) just to be more clear about the > scenario where this helps. Sure. > >> >> Dev Jain (3): >> mm: Call pointers to ptes as ptep >> mm: Add generic helper to hint a large folio >> mm: Optimize mremap() by PTE batching >> >> include/linux/pgtable.h | 16 +++++++++++++++ >> mm/mremap.c | 44 +++++++++++++++++++++++++++-------------- >> 2 files changed, 45 insertions(+), 15 deletions(-) >>