From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 51583C41535 for ; Tue, 19 Dec 2023 08:19:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7VibTNed372ckeByyx4b1eaqqwitzm+mVDAueQ0J0HI=; b=JKsk+AmKCaNxR/ SiKCn0A8eQo8vDUpKcULwYGIEkILvAuUoVJstWVlP22kbiw6bAE1wgw9SJQ18GAHcVW6U9kTEH7sD T9LHEVnwc1XInSF6ZYJuYwP4ES+rohtuYdDU57dypPZCttP/W7+qWQE7+uBMYzCcgNuaQkDJk3k5w bF121GQrTkwaq60S3Ypoc8Bxwbp3D7Z4XIsQJhHJksnPoeQG6gscOJkcVDilZNbklIUlxO0dmkB22 WGyVoHW4khb/HEKl761Fleg5nMdrjbHz76cjpxtz9a+tq7j+fsEBplWOz2pl14HlQXOV1T8H4qi2b ZKWxpccz1TD/tVuiTADg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rFVJA-00DHVu-0H; Tue, 19 Dec 2023 08:18:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rFVJ6-00DHTo-2C for linux-arm-kernel@lists.infradead.org; Tue, 19 Dec 2023 08:18:30 +0000 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 45EB31FB; Tue, 19 Dec 2023 00:19:07 -0800 (PST) Received: from [10.57.75.230] (unknown [10.57.75.230]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E3D2F3F738; Tue, 19 Dec 2023 00:18:18 -0800 (PST) Message-ID: Date: Tue, 19 Dec 2023 08:18:17 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 01/16] mm: thp: Batch-collapse PMD with set_ptes() Content-Language: en-GB To: David Hildenbrand , Catalin Marinas , Will Deacon , Ard Biesheuvel , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , Anshuman Khandual , Matthew Wilcox , Yu Zhao , Mark Rutland , Kefeng Wang , John Hubbard , Zi Yan , Barry Song <21cnbao@gmail.com>, Alistair Popple , Yang Shi Cc: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20231218105100.172635-1-ryan.roberts@arm.com> <20231218105100.172635-2-ryan.roberts@arm.com> <8ce9f79c-be2f-4fa2-b356-39436a1d108a@redhat.com> From: Ryan Roberts In-Reply-To: <8ce9f79c-be2f-4fa2-b356-39436a1d108a@redhat.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231219_001828_766598_7F08932D X-CRM114-Status: GOOD ( 12.30 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 18/12/2023 17:40, David Hildenbrand wrote: > On 18.12.23 11:50, Ryan Roberts wrote: >> Refactor __split_huge_pmd_locked() so that a present PMD can be >> collapsed to PTEs in a single batch using set_ptes(). It also provides a >> future opportunity to batch-add the folio to the rmap using David's new >> batched rmap APIs. > > I'd drop that sentence and rather just say "In the future, we might get rid of > the remaining manual loop by using rmap batching.". OK fair enough. Will fix for next version. > >> >> This should improve performance a little bit, but the real motivation is >> to remove the need for the arm64 backend to have to fold the contpte >> entries. Instead, since the ptes are set as a batch, the contpte blocks >> can be initially set up pre-folded (once the arm64 contpte support is >> added in the next few patches). This leads to noticeable performance >> improvement during split. >> > Acked-by: David Hildenbrand Thanks! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel