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 77B6FFEEF38 for ; Tue, 7 Apr 2026 13:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=egPHa+K7bRIsEovZ/NkxHxwL2y6jSYz+NfZ+J1+t58s=; b=34impLXO3rRdTnEScmUbsGvXZc l8Ae0XBO8E/R4LJYkk+Ud7z1YRVzCYxbk9cWfORr476pJcfUAnOSqxvJ7kK0BvmdMY3ksCo/utaW6 N5mkBYKMNb5o2j2EWTZ5JCSwasQJ17ZXoKgfEvZthdM/iBicwu4RQDxU7d51HiLsDbMSWa9d5Ehe5 aUsK6ymUnj7ooE6apm9P82I91wfl7eDGPXrJiaylPHYZ4hUQs0QtC1zHFxLx9EwPiPGUI5UlWzWv9 RwWUj+vqG+Lr4JsImzk06EAr+8MyuKd0KWt8DXVNtZvPJiOYWhzlW9XCwi4onGu7fLn9L/i1tDq13 4wwxhFWA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wA6mW-00000006XWx-3WO3; Tue, 07 Apr 2026 13:47:52 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wA6mU-00000006XWR-0iNu for linux-arm-kernel@lists.infradead.org; Tue, 07 Apr 2026 13:47:51 +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 44D8A16F2; Tue, 7 Apr 2026 06:47:43 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CEB003F7D8; Tue, 7 Apr 2026 06:47:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1775569669; bh=YCxm5IsUZWkOVmsnnCElZfL8KDjU6K9uk5Pr3gZX1nc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VVPYMBNyFaH6onWlNAwGCgXqVZGQkTcoMTSFGWNL93JMN3nv3BLkZePnFnacj6De6 jCgyNxQVNTeX+ACgzoSM21XwGim9Q6AvQrjUQfyJ5TKZm5oaT1z/rI/wZROF8uDTZy NzlrzHYBnkils0WuAfTTUSw1Dh9VbZRQ9Ut2ROTM= Date: Tue, 7 Apr 2026 14:47:45 +0100 From: Catalin Marinas To: Linus Walleij Cc: Will Deacon , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH] arm64: clear_page[s] using memset Message-ID: References: <20260306-aarch64-clear-pages-c-v1-1-77c1bb0f1c21@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260407_064750_256720_CB30B87F X-CRM114-Status: GOOD ( 10.52 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Apr 07, 2026 at 11:25:55AM +0200, Linus Walleij wrote: > Quoting my own commit message hehe: > > > No performance regressions can be seen, the fastpath > > benchmarks differences are in the noise. > > This was tested on hardware with Ryan Robert's fastpath tool. BTW, have you tried the perf bench mmap test again with the new clear_page? Both with single page and multiple pages scenarios. And ideally on more than one platform. Will pointed out (in a private chat) that current clear_page() uses non-temporal stores while memset() doesn't. It may not make any difference in practice but it would be good to have some numbers. -- Catalin