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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 43005C00454 for ; Tue, 10 Dec 2019 15:46:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0288420836 for ; Tue, 10 Dec 2019 15:46:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ogjctMbS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0288420836 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9A7E76B2D0E; Tue, 10 Dec 2019 10:46:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 958A86B2D0F; Tue, 10 Dec 2019 10:46:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 847726B2D10; Tue, 10 Dec 2019 10:46:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0224.hostedemail.com [216.40.44.224]) by kanga.kvack.org (Postfix) with ESMTP id 6CB946B2D0E for ; Tue, 10 Dec 2019 10:46:32 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 192E75848 for ; Tue, 10 Dec 2019 15:46:32 +0000 (UTC) X-FDA: 76249659024.13.brain88_732e1a1b38319 X-HE-Tag: brain88_732e1a1b38319 X-Filterd-Recvd-Size: 5844 Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Dec 2019 15:46:31 +0000 (UTC) Received: by mail-pl1-f195.google.com with SMTP id x17so43963pln.1 for ; Tue, 10 Dec 2019 07:46:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Rhfl0pj5au2KnJmwhjeT97g46p4i/DRaXShR2ok5irQ=; b=ogjctMbSOB5Sb9JjVoRGf7ox57Lu/1pkqV8At4y7SRHAPT0c9FrBGsWmqPgHvczTtL z6q9kVYaV6WKxVmFm56AOT4b55pUPorEO4eN71kVqYBobcpypfxq0n3MizCEwWW/6spW mj8YrFyUwY/Im+qLvrntjDVmZGsGU3STAMyZ4gDWXqf1m0hhgyq4iLEUo5dLldVx8VI+ 6a1MI+EN1sC2mO/nzdEyDvTqGNHilYcrrmwulYkV3sK3I1bfWtcWLUrzhR8ZrNmsaePP vYV10k/IUNQJBSb5rwFDavORfULYxmc5/wegGxpN1Te2E+JkdEvrw7tLNkIOKmK/nxmp OuJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Rhfl0pj5au2KnJmwhjeT97g46p4i/DRaXShR2ok5irQ=; b=T1En0ZuXtiKKM4XeqBfoqIJzET6CzHiRU8fZxi3Q5QGH6gnreBsXwiweb6EyNiFDrs +NeR7E8h/22DYka8br4LDzTKUMFaoOzUisRTmzKDUWozwcQ5sSIqiO1H1ZkAcFDaSETW mNHvXX8FlmVsooRWrrFrozzOFsHe6qJxX5TgQ9/XepKHzoWnhFs3lKApQIOOeKXtkLy5 dc02dkm6KAHCNL3BYH4ZGXGA6gSQ0Txct0Z0/c3mWwXGtp3F4TqQMYtyuskCdSbGpFAA iqSLINERLNmbI/Iq+ocZSndNO3/ZQkTN3Bkl6Rx+x5JamP0gxYJ/LX45zRRH1q2j9Jts 0Fmg== X-Gm-Message-State: APjAAAXTUylb/YOrMHpyHYfG0EFVOwbVmu8M98XJoH2EOTB2AWPuvZmj YiXQBPrV9SYizswdQmrdoy8= X-Google-Smtp-Source: APXvYqwUisIpRC5v3E6jdY7aD+c/0u3eTGW1biMT4kYCSUD9kmjZnHYWUO97ANOmELGjB+FpxrDykA== X-Received: by 2002:a17:90a:fc94:: with SMTP id ci20mr5918591pjb.6.1575992790504; Tue, 10 Dec 2019 07:46:30 -0800 (PST) Received: from localhost.corp.microsoft.com ([167.220.255.5]) by smtp.googlemail.com with ESMTPSA id k13sm4113815pfp.48.2019.12.10.07.46.25 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 10 Dec 2019 07:46:30 -0800 (PST) From: lantianyu1986@gmail.com X-Google-Original-From: Tianyu.Lan@microsoft.com To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, sashal@kernel.org, akpm@linux-foundation.org, dan.j.williams@intel.com, jgg@ziepe.ca, dave.hansen@linux.intel.com, david@redhat.com, namit@vmware.com, richardw.yang@linux.intel.com, christophe.leroy@c-s.fr, tglx@linutronix.de, Tianyu.Lan@microsoft.com, osalvador@suse.de, michael.h.kelley@microsoft.com Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, vkuznets@redhat.com, eric.devolder@oracle.com Subject: [RFC PATCH 1/4] mm/resource: Move child to new resource when release mem region. Date: Tue, 10 Dec 2019 23:46:08 +0800 Message-Id: <20191210154611.10958-2-Tianyu.Lan@microsoft.com> X-Mailer: git-send-email 2.14.5 In-Reply-To: <20191210154611.10958-1-Tianyu.Lan@microsoft.com> References: <20191210154611.10958-1-Tianyu.Lan@microsoft.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Tianyu Lan When release mem region, old mem region may be splited to two regions. Current allocate new struct resource for high end mem region but not move child resources whose ranges are in the high end range to new resource. When adjust old mem region's range, adjust_resource() detects child region's range is out of new range and return error. Move child resources to high end resource before adjusting old mem range. Signed-off-by: Tianyu Lan --- This patch is to prepare for memory hot-remove function in Hyper-V balloon driver. --- kernel/resource.c | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 76036a41143b..1c7362825134 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -181,6 +181,38 @@ static struct resource *alloc_resource(gfp_t flags) return res; } +static void move_child_to_newresource(struct resource *old, + struct resource *new) +{ + struct resource *tmp, **p, **np; + + if (!old->child) + return; + + p = &old->child; + np = &new->child; + + for (;;) { + tmp = *p; + if (!tmp) + break; + + if (tmp->start >= new->start && tmp->end <= new->end) { + tmp->parent = new; + *np = tmp; + np = &tmp->sibling; + *p = tmp->sibling; + + if (!tmp->sibling) + *np = NULL; + continue; + } + + p = &tmp->sibling; + } +} + + /* Return the conflict entry if you can't request it */ static struct resource * __request_resource(struct resource *root, struct resource *new) { @@ -1246,9 +1278,6 @@ EXPORT_SYMBOL(__release_region); * Note: * - Additional release conditions, such as overlapping region, can be * supported after they are confirmed as valid cases. - * - When a busy memory resource gets split into two entries, the code - * assumes that all children remain in the lower address entry for - * simplicity. Enhance this logic when necessary. */ int release_mem_region_adjustable(struct resource *parent, resource_size_t start, resource_size_t size) @@ -1331,11 +1360,12 @@ int release_mem_region_adjustable(struct resource *parent, new_res->sibling = res->sibling; new_res->child = NULL; + move_child_to_newresource(res, new_res); + res->sibling = new_res; ret = __adjust_resource(res, res->start, start - res->start); if (ret) break; - res->sibling = new_res; new_res = NULL; } -- 2.14.5