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=-18.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 254B0C4338F for ; Mon, 9 Aug 2021 07:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01E1561002 for ; Mon, 9 Aug 2021 07:42:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233520AbhHIHmz (ORCPT ); Mon, 9 Aug 2021 03:42:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:34152 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233467AbhHIHmx (ORCPT ); Mon, 9 Aug 2021 03:42:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628494952; 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=rpTchTW2WHBbp1FKZwjHPai3s4d7skP1b3ls4uFFkQM=; b=VOMQEzhr9grrnoTBTxRICfIpqMVHm8yvO2nxzJvBZMLEhjXc3E7KbcJIfMKmVEXnuBqiZ9 AYtQHVKC15CoTGkp4CNRQeqccgBgE+f1K1ppzDRedIkMO89vMQ1vvV48O9CAP51S7OuxFv rczKIFfdSryWYJstljIZuUCorH7Ffpg= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-309-Q7RPeezcP8epFNQAXxi9qA-1; Mon, 09 Aug 2021 03:42:29 -0400 X-MC-Unique: Q7RPeezcP8epFNQAXxi9qA-1 Received: by mail-wr1-f72.google.com with SMTP id z1-20020adfdf810000b0290154f7f8c412so168337wrl.21 for ; Mon, 09 Aug 2021 00:42:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=rpTchTW2WHBbp1FKZwjHPai3s4d7skP1b3ls4uFFkQM=; b=HmUc1UGEhnCS7prnb0ZuSQpvQLbHBmAZSr3tq38YHKbEUuaIvB5Q6AeMP4j/shBfID Vd3tCm/RHqQm4Wk69G5caeoV/V2kKXqdcfrPuhC6pe0CHzJTcgvBfvT9J7m/0zIYoAAT 8PUkadJqT0t9R6efGt0Q6Lstl/nwTh9XDIOv3THyrKUciPjoiUksKxaq691wCrftq9Rv 5yq2zQ0sW6p/5zfIwNdnXvdzJYAL+gnsQbc+Y1j1wEGy5n+7laXdnllGkyX+Jxlq1ggh ZtUNSGq+41LOdIlUeT64Vl17+Uw9mMKb8YFVxrR9RZLfWobGjGWYf1cUWuFnHDVFSt2/ GRZA== X-Gm-Message-State: AOAM530lfxrCb29rKBwu3u4RdwsWUpkNjdbeIimRnO+J8ll7lzgA8HoE iWKpy7bdfszg3jUP8napMCqIGtYkVVsPwB8Y8lVP/5rL/npd00yhH9gpNIb8yOO3Ts95S4s10XY hMGr1BhmVQ1dFQxy45jiRnhTO X-Received: by 2002:a5d:4a50:: with SMTP id v16mr785820wrs.77.1628494948483; Mon, 09 Aug 2021 00:42:28 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzxIs0Mx3OKFD9xz5+nORNxkQlRcKGJL37rseXuAmlE7FZXZNGrGWmsWEyh3ihAd2BaJSF+0Q== X-Received: by 2002:a5d:4a50:: with SMTP id v16mr785813wrs.77.1628494948372; Mon, 09 Aug 2021 00:42:28 -0700 (PDT) Received: from ?IPv6:2003:d8:2f0a:7f00:fad7:3bc9:69d:31f? (p200300d82f0a7f00fad73bc9069d031f.dip0.t-ipconnect.de. [2003:d8:2f0a:7f00:fad7:3bc9:69d:31f]) by smtp.gmail.com with ESMTPSA id a11sm4453865wrw.67.2021.08.09.00.42.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Aug 2021 00:42:28 -0700 (PDT) Subject: Re: [RFC PATCH 10/15] virtio: virtio_balloon: use PAGES_PER_SECTION instead of MAX_ORDER_NR_PAGES. To: Zi Yan , linux-mm@kvack.org Cc: Matthew Wilcox , Vlastimil Babka , "Kirill A . Shutemov" , Mike Kravetz , Michal Hocko , John Hubbard , linux-kernel@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , virtualization@lists.linux-foundation.org References: <20210805190253.2795604-1-zi.yan@sent.com> <20210805190253.2795604-11-zi.yan@sent.com> From: David Hildenbrand Organization: Red Hat Message-ID: <3e27818c-970d-7138-0258-928274bf294e@redhat.com> Date: Mon, 9 Aug 2021 09:42:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210805190253.2795604-11-zi.yan@sent.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05.08.21 21:02, Zi Yan wrote: > From: Zi Yan > > It keeps the existing behavior when MAX_ORDER grows beyond a section. > ... but it breaks/changes existing behavior if MAX_ORDER is smaller than a section? > Signed-off-by: Zi Yan > Cc: "Michael S. Tsirkin" > Cc: David Hildenbrand > Cc: Jason Wang > Cc: virtualization@lists.linux-foundation.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/virtio/virtio_balloon.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 47dce91f788c..de8d0355d827 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -36,7 +36,7 @@ > #define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \ > __GFP_NOMEMALLOC) > /* The order of free page blocks to report to host */ > -#define VIRTIO_BALLOON_HINT_BLOCK_ORDER (MAX_ORDER - 1) > +#define VIRTIO_BALLOON_HINT_BLOCK_ORDER (PFN_SECTION_SHIFT - 1) > /* The size of a free page block in bytes */ > #define VIRTIO_BALLOON_HINT_BLOCK_BYTES \ > (1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT)) > -- Thanks, David / dhildenb