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 EB124278759 for ; Tue, 6 May 2025 09:16:27 +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=1746522989; cv=none; b=hjJQT1h2F5tEzTehmTJD88m5YpFBOVTXkpFVnjXG7jZTBdy2ssMO8VGknPmgapJ5IXTMexpQiT3ptSlbEm4iX+x3JUyeqAHYkRNHcANGXC9gBHX76F0uXjt7U0s6y2Q99HoZBUc6bsvlo+kh46dzlDyy3mhGZ2LlQ2KQRPiaybI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746522989; c=relaxed/simple; bh=qPFHgHnT4BdXsfQjhuHPGPviCnIRn4Xp2l8althg+MQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=d92zG8b/f3QfmF6M84D7yjKVgIuIMdeBPDz2JYyLM6mDRor+iqFGaXKvXYZE8LYZm4D40qFYoTrtn/EXGyZZ3ndpkXXFQUJ9NrT9fhH9g3VOw8/Ht9Xp07DIL4whVtKty9h58avNV1k5Dbor1EqSg6miWfnsRftBbug8k+89gA4= 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 4569F113E; Tue, 6 May 2025 02:16:17 -0700 (PDT) Received: from [10.163.54.208] (unknown [10.163.54.208]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8FC403F5A1; Tue, 6 May 2025 02:16:19 -0700 (PDT) Message-ID: Date: Tue, 6 May 2025 14:46:15 +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: Dev Jain , 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: Anshuman Khandual In-Reply-To: <20250506050056.59250-1-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit 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. > > 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(-) >