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 2057DC47258 for ; Tue, 23 Jan 2024 17:26:03 +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:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qJ3yl/4EyPd9eQP+4P3IzUIYgFQ2afz0MHwPxGDMEl4=; b=k1WAr/0pl8qJxt M0LaBS7fJ0O5dMonl3SVlXNAzJCoqj6P8tg5o84Ja4qC0p+ZC1QFovvFfe3yGZePItFrzvF+eFMPv p9XkH//AQ/0fHyocKCobX0w+WEdclOtIUHJhQDyDFytyheyIPNaOtwamdub3vMLhbw+9MBN8W8xu8 xzxMFuCAg88+6S2M7bz0lze6Ka3H8Aa93gMxeMD7r75pveCoqqpcI/M2tvZo7VKtzT3qrHslLTWAY ST1Kr5/U58Z4J2FJzCi1cHNfzo7+hPRZ+UMAD57tgxultLAntTtLyOo5VKSypXehDm3LMLm4XTPoq blCSo9DGUH1AT1sPpq8w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rSKWi-00HUtj-2k; Tue, 23 Jan 2024 17:25:32 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rSKWf-00HUrv-2N for linux-arm-kernel@lists.infradead.org; Tue, 23 Jan 2024 17:25:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender: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-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Bjhb2hfzK/8i0tKZI56owzt2KGG7OFmwSuGm4x1P2gU=; b=IgE1LKcSfIHc7PJOysQSDI9e3C hk4sUUEKr51UKs1Bvg2k8X8ZunFhmWH3DahtvnfuXpMFc7SgSPvGLkqwbMK53IzfZP2S9xBwHA8py 0z8BkvLbqaNoDo3qdH1Uh3Z8yoxxIeepfkheorVEfCypvlM8r1toj4PIcQlleaoq2fo1FfMuaOxwc YG3lKqsWN7cLSCyd17HeYHkpuD7UfNrfLfodJuKEKgSa6D2DTNC4NyYkEru0CisHqpwEFPi/2AGSa crYK2F1J9b4mtzFEJ1XbW9vQ0RPDnruau/wu18s7gFZbGO9DOja8ZARQ6QnhXRTJujpRSYcA4UlcB MOOXwRHQ==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:42660) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1rSKWX-0002q9-2X; Tue, 23 Jan 2024 17:25:21 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1rSKWQ-00027i-Vs; Tue, 23 Jan 2024 17:25:15 +0000 Date: Tue, 23 Jan 2024 17:25:14 +0000 From: "Russell King (Oracle)" To: Yuquan Wang Cc: jiahao.os@bytedance.com, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v3 00/19] arm64 kernel text replication Message-ID: References: <20240123103509.696983-1-wangyuquan1236@phytium.com.cn> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240123103509.696983-1-wangyuquan1236@phytium.com.cn> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240123_092529_771938_1ACB2B40 X-CRM114-Status: GOOD ( 14.70 ) 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 Tue, Jan 23, 2024 at 06:35:09PM +0800, Yuquan Wang wrote: > > > > After applying these patches, we tested that our business performance > > increased by more than 5% and the NUMA node memory bandwidth was more > > balanced. > > > > I have successfully applied your patches on my arm64 linux. And I could > start it with a qemu machine(virt). However, I don't know the way to test > the performance it brings to the kernel. Do you have some suggestions? Please can I make one thing utterly clear... kernel text replication in a virtual machine generally doesn't make sense unless one can setup the virtual machine to be truly NUMA. In other words, groups of CPUs with their local memory and remote-node memory having higher latency. Kernel text replication is something which solves the problem on bare metal NUMA machines where running kernel text that is located in a foreign node results in the CPU running slower than it would do if the kernel text were in its local RAM. Unless the VM is setup in exactly that way, then kernel text replication has no place in a VM, and probably would result in poorer performance. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel