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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4144C433EF for ; Wed, 8 Dec 2021 08:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245036AbhLHIma (ORCPT ); Wed, 8 Dec 2021 03:42:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:47973 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240959AbhLHIm2 (ORCPT ); Wed, 8 Dec 2021 03:42:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638952736; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G645m0btAwFcCTWX1rUo8pbQn2SjCg+rXpPM0KNcd2A=; b=CcF5qcA0SHMhifgr5PT0D1NFhvwzMjfMiLQHaJwAGC2RYRx2JZ4GMZjK4Ij1VLQogfcAyj BhvgoXrukCtXTHdueWGZjNvxJDdx0tq6QKXOagueU94H9ChASxdBgQzzd2ZJNHwHv9jE7H 69C3RgKri/mDVqjjZZRRVmsJADhiGjg= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-191-A86ZKkdbNC2ZGjyu2JDwMQ-1; Wed, 08 Dec 2021 03:38:55 -0500 X-MC-Unique: A86ZKkdbNC2ZGjyu2JDwMQ-1 Received: by mail-wm1-f72.google.com with SMTP id g81-20020a1c9d54000000b003330e488323so996756wme.0 for ; Wed, 08 Dec 2021 00:38:55 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:organization:in-reply-to :content-transfer-encoding; bh=G645m0btAwFcCTWX1rUo8pbQn2SjCg+rXpPM0KNcd2A=; b=UT4QB+UstKGNlettRapJS8QJMjM2kAWb8u9jJp5PG6Sg8r1msJuKtK96pxDBn4uO9z U89uuIYLlWD/rfT01z2c7jlW3Rmo8JiiNpKQx/7qq4hQ3BlFjxgtei/d+xBA8EYRS84E c7lElEIHHUqPvmizsZv56G2MXSXbqkOQhifaQ6jJ4SgsuE8B3o/cQQrzsxlATWo8X8be pOcNIgUUgBeE75JhBbfy8leRN8GEnN0RIQ2dD/jA6jbfksddO/AQ0yE6tN3+mE6O1cL9 bQ2bJmj9yFwVGXquP029p2aY50ODxF2BAa2CB2WN+vbv3W3es3rFQ2wPYYdCcRkV5P/T DWTw== X-Gm-Message-State: AOAM532UkRk0TPc/kHFhsYporE1i5yw7cxEzFMGNNIRCAx5ovrN+AXyZ ygonIaXCd6AM9jQjEWCThPdyC/Q3mVPJJGdjGFd7KPrIU7ea+dX9Oa3QjU+DFuzOa9zz5+d6Clv q3eBEn2iYTu0E5WCW1/b+Jmo6 X-Received: by 2002:a5d:4843:: with SMTP id n3mr55905080wrs.335.1638952734104; Wed, 08 Dec 2021 00:38:54 -0800 (PST) X-Google-Smtp-Source: ABdhPJx8h3GpVBEghmbyHhF2c8p2hpDjA+y5sYdpp+Th4+TAlULBhYUkaCk8clV8RtI1801/TKzJVA== X-Received: by 2002:a5d:4843:: with SMTP id n3mr55905055wrs.335.1638952733897; Wed, 08 Dec 2021 00:38:53 -0800 (PST) Received: from [192.168.3.132] (p5b0c62ba.dip0.t-ipconnect.de. [91.12.98.186]) by smtp.gmail.com with ESMTPSA id a22sm2024634wme.19.2021.12.08.00.38.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 08 Dec 2021 00:38:53 -0800 (PST) Message-ID: <2c790c6c-22e4-687f-6ecd-368683d781a3@redhat.com> Date: Wed, 8 Dec 2021 09:38:52 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v3] mm: fix panic in __alloc_pages Content-Language: en-US To: Michal Hocko Cc: Alexey Makhalov , Dennis Zhou , Eric Dumazet , "linux-mm@kvack.org" , Andrew Morton , Oscar Salvador , Tejun Heo , Christoph Lameter , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" References: <2E174230-04F3-4798-86D5-1257859FFAD8@vmware.com> <21539fc8-15a8-1c8c-4a4f-8b85734d2a0e@redhat.com> <78E39A43-D094-4706-B4BD-18C0B18EB2C3@vmware.com> <5a44c44a-141c-363d-c23e-558edc23b9b4@redhat.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> >> I think we'll soon might see setups (again, CXL is an example, but als >> owhen providing a dynamic amount of performance differentiated memory >> via virtio-mem) where this will most probably matter. With performance >> differentiated memory we'll see a lot more nodes getting used in >> general, and a lot more nodes eventually getting hotplugged. > > There are certainly machines with many nodes. E.g. SLES kernels are > build with CONFIG_NODES_SHIFT=10 which is a lot of potential nodes. > And I have seen really large machines with many nodes but those usually > come with a lot of memory and they do not tend to have non populated > nodes AFAIR. Right, and is about to change as nodes are getting used to represent memory with differing performance characteristics/individual devices, not the traditional "this is a socket" setup: we'll see more and more small (virtual) machines with multiple nodes and eventually many possible nodes. -- Thanks, David / dhildenb