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 X-Spam-Level: X-Spam-Status: No, score=-9.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DD43C433E8 for ; Mon, 27 Jul 2020 09:41:37 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D6BB2070B for ; Mon, 27 Jul 2020 09:41:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D6BB2070B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BFZZP30y2zF0RC for ; Mon, 27 Jul 2020 19:41:33 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kaod.org (client-ip=178.32.125.228; helo=12.mo6.mail-out.ovh.net; envelope-from=clg@kaod.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=kaod.org Received: from 12.mo6.mail-out.ovh.net (12.mo6.mail-out.ovh.net [178.32.125.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BFZWD4YF3zDqBK for ; Mon, 27 Jul 2020 19:38:48 +1000 (AEST) Received: from player695.ha.ovh.net (unknown [10.108.35.240]) by mo6.mail-out.ovh.net (Postfix) with ESMTP id 5B5CD221141 for ; Mon, 27 Jul 2020 11:38:40 +0200 (CEST) Received: from kaod.org (bad36-1-78-202-132-1.fbx.proxad.net [78.202.132.1]) (Authenticated sender: clg@kaod.org) by player695.ha.ovh.net (Postfix) with ESMTPSA id 8891A14979797; Mon, 27 Jul 2020 09:38:33 +0000 (UTC) Authentication-Results: garm.ovh; auth=pass (GARM-101G0045a1d8947-986f-459b-a880-f86db548c305,F8FE5446E6A712E1B8ADD27A8D09714C92F8C0F3) smtp.auth=clg@kaod.org Subject: Re: [PATCH] KVM: PPC: Book3S HV: increase KVMPPC_NR_LPIDS on POWER8 and POWER9 To: Paul Mackerras References: <20200608115714.1139735-1-clg@kaod.org> <20200723062016.GE213782@thinks.paulus.ozlabs.org> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= Message-ID: <848f132c-eb13-fa80-6637-e52f90296b99@kaod.org> Date: Mon, 27 Jul 2020 11:38:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200723062016.GE213782@thinks.paulus.ozlabs.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Ovh-Tracer-Id: 11573969568935545789 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduiedriedtgddulecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefuvfhfhffkffgfgggjtgfgsehtkeertddtfeejnecuhfhrohhmpeevrogurhhitggpnfgvpgfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepfeffvddtudegieefudeugffhjefgieegieegleettdehgfeiieevueeihfegfefgnecukfhppedtrddtrddtrddtpdejkedrvddtvddrudefvddrudenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphdqohhuthdphhgvlhhopehplhgrhigvrheileehrdhhrgdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomheptghlgheskhgrohgurdhorhhgpdhrtghpthhtoheplhhinhhugihpphgtqdguvghvsehlihhsthhsrdhoiihlrggsshdrohhrgh X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Nicholas Piggin , kvm@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 7/23/20 8:20 AM, Paul Mackerras wrote: > On Mon, Jun 08, 2020 at 01:57:14PM +0200, Cédric Le Goater wrote: >> POWER8 and POWER9 have 12-bit LPIDs. Change LPID_RSVD to support up to >> (4096 - 2) guests on these processors. POWER7 is kept the same with a >> limitation of (1024 - 2), but it might be time to drop KVM support for >> POWER7. >> >> Tested with 2048 guests * 4 vCPUs on a witherspoon system with 512G >> RAM and a bit of swap. >> >> Signed-off-by: Cédric Le Goater > > Thanks, patch applied to my kvm-ppc-next branch. We have pushed the limits further on a 1TB system and reached the limit of 4094 guests with 16 vCPUs. With more vCPUs, the system starts to check-stop. We believe that the pages used by the interrupt controller for the backing store of the XIVE internal tables (END and NVT) allocated with GFP_KERNEL are reclaimable. I am thinking of changing the allocation flags with : __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC because XIVE should be able to fail gracefully if the system is low on mem. Is that correct ? Thanks, C.