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 2297AC4345F for ; Mon, 15 Apr 2024 07:36:38 +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:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=7y/ypLgolmBGjCU/8l1gyatIcafvgFH+El5WnopSPeI=; b=1G3gOwYgF3zsyl ElMvA+Gv+DbgYCVhecvjpCqWAqqzmactvW+ia+PcCvPWQ9O6KJcIyFso5PPVw2dfPRrvuyram7VyD 4lGg4iTgLATWWxaI/aXsxeE46t9eQ9kee/ub1KQYBASwIyYpZ3Lraiw2cMxe3cE9jxH0aLDnrpqz+ JzBJMNuqjECelWe3Y+qg+X9lJxvoBXumxKndDnKYLm+itZ3eCpSQEDbW9ZVt2IdQ38TL24XzG9mV6 abjGJdWZYsZiQhVBgShRdRxUGg5tXdE2XjnhAJSPnEKSpCvZylVaa7BwtNXVQ37dmnKgtqh6sPKnY T5d9izfyBZMT9IPdI8Sg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwGt6-00000007Mms-2BZL; Mon, 15 Apr 2024 07:36:24 +0000 Received: from sin.source.kernel.org ([2604:1380:40e1:4800::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rwGt2-00000007MlJ-40v5 for linux-arm-kernel@lists.infradead.org; Mon, 15 Apr 2024 07:36:22 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 2E3B5CE0AD0; Mon, 15 Apr 2024 07:36:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FF47C113CC; Mon, 15 Apr 2024 07:36:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713166577; bh=52Kn17ZLYLK+5+c8svnzlHh6hj5GWIXovfTevpAw/bA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=A2gKpZ3Iv5/lYa4BXluiQCrNDwrimsmcTKYB9KCZ/c3gHfdPGgM4BAPi30LxG5sNi qDZFULjougAy3EDhb695tD5kf7veyeUh3tBOSKpNLOkQh+CKMGXZqUYnd4pE6k4xEO TrDr7OlhqSdgMgqSn1stTDhKV/zW0rQNshK51L6CQZe0ig31l4XVjUmAyUOPHcP3ni R2VTxh9uTl2CIkTNgXm47sURNTFqSStauLUyLpuqg7Uug9dHnFXZH5tXURE8Rv2qnz cmh25lQE30EIHGfejzWlsk1YnRk0DHlqRIi3OmXqcShRE2bmEOFqWO5iMEgbQ/W/5F th1ecs94yHh1A== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rwGsw-004Wl8-Mh; Mon, 15 Apr 2024 08:36:14 +0100 Date: Mon, 15 Apr 2024 08:36:14 +0100 Message-ID: <86bk6brsb5.wl-maz@kernel.org> From: Marc Zyngier To: Li RongQing Cc: oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: Re: [PATCH] KVM: arm64: Consider NUMA affinity when allocating per-CPU stack_page In-Reply-To: <20240415033614.43518-1-lirongqing@baidu.com> References: <20240415033614.43518-1-lirongqing@baidu.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/29.2 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: lirongqing@baidu.com, oliver.upton@linux.dev, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240415_003621_379774_DB15A1F5 X-CRM114-Status: GOOD ( 23.54 ) 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 Mon, 15 Apr 2024 04:36:14 +0100, Li RongQing wrote: > > per-CPU stack_page are dominantly accessed from their own local CPUs, > so allocate them node-local to improve performance. Do you have any performance data to back this up? Given that this is only used in the non-VHE case, and that by doing so you have left quite a lot of performance on the floor already, I'm even more surprised to see the performance argument. Furthermore, you don't address the allocation of per-CPU data, which has a much larger potential impact, given how the HYP code is structured. > > Signed-off-by: Li RongQing > --- > arch/arm64/kvm/arm.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index c4a0a35..d745d01 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -2330,15 +2330,15 @@ static int __init init_hyp_mode(void) > * Allocate stack pages for Hypervisor-mode > */ > for_each_possible_cpu(cpu) { > - unsigned long stack_page; > + struct page *page; > > - stack_page = __get_free_page(GFP_KERNEL); > - if (!stack_page) { > + page = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, 0); > + if (!page) { > err = -ENOMEM; > goto out_err; > } > > - per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page; > + per_cpu(kvm_arm_hyp_stack_page, cpu) = page_address(page); > } > > /* The patch itself looks correct, however partial and lacking some convincing data. M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel