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 5BD3AC33C9E for ; Tue, 7 Jan 2020 13:10:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D8162087F for ; Tue, 7 Jan 2020 13:10:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="u+mZfaCp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728213AbgAGNKI (ORCPT ); Tue, 7 Jan 2020 08:10:08 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:39998 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727814AbgAGNKH (ORCPT ); Tue, 7 Jan 2020 08:10:07 -0500 Received: by mail-pf1-f194.google.com with SMTP id q8so28591268pfh.7; Tue, 07 Jan 2020 05:10:07 -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=L4Z8duDWCUM2mJLHo/CutVp9BmlGq7NQNayTELBVq3A=; b=u+mZfaCpsqbZj/Qw4NFdG+qQUVK8y3xMNT891jjwBEJ0Ovf4o8eD5wdRx+GWdDEZuA Oh1ShGwM2H3F4rAN5pypzbZB+bO9l6qtbIhVujRbPCGtZ5IqZIXPooE2izUzQ3xh8t6q qrWarSRTJPLckE8oJBLwGvIOm8vN8l2UkfQBv78nBu4qQoGQKYNtbZgq4gYoN0dgb6O1 7C7/4nHK1cNCs/P8sLsRQWCCKcqlv17iVa9uMRfrebtcIZZ/PsgZCWWZ25paQxMv55V3 Pca0EjRButB+z2+H9PU7pn/4nEVDFs2i6jr5UmfYBDrQkaHfhBNjlUz+tRG8y8xEw2R3 O1oQ== 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=L4Z8duDWCUM2mJLHo/CutVp9BmlGq7NQNayTELBVq3A=; b=n7Ad1KokaSrmwA22RYDN/RWB/94qJzIPSiPNc0EZXb3jmJNUUNyLTLvNez4kn//Fnh J+tcwlHGyH0j1ghLdhiNvdtYjgm0hlJvqUhYon4EvIhxnilA0dv/8E/k40OWSshARE/N RtZBd8to2GAQ/OHbF/VlTfnu84ixxZZrkVJx46YCfYj2Gkf0gPSy73XignSTq2fR9TkB p1QSpZhi8H9GUXsUzbTp2LF2dpzEF7432y+KYze94JvJtkLvFBH6itTt7nwCmmBEakK/ 3lpqqHx6OdKnKrWNRfXS6GFucEP4Z3yve5lezPqkDSm9+oImJsBzCvmrcq4MXBmmWw/i xOtA== X-Gm-Message-State: APjAAAUxxwobcrnyLG8ckp4C554IZSaelKaMrEmlaN0PZpY5BJJrFpqy xawSw1piOV1jvQAo/tMSYcM= X-Google-Smtp-Source: APXvYqzkwOFLqU1282H6O87p4FpwS9gL6cvxA9uCi9krUbs+q7M5ZZG4wdRBe0T4EB5NPImc9YxhAQ== X-Received: by 2002:aa7:81c7:: with SMTP id c7mr12284472pfn.203.1578402607173; Tue, 07 Jan 2020 05:10:07 -0800 (PST) Received: from localhost.corp.microsoft.com ([167.220.255.5]) by smtp.googlemail.com with ESMTPSA id m71sm27522400pje.0.2020.01.07.05.10.02 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 Jan 2020 05:10:06 -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, richardw.yang@linux.intel.com, namit@vmware.com, Tianyu.Lan@microsoft.com, david@redhat.com, christophe.leroy@c-s.fr, 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 V2 1/10] mm/resource: Move child to new resource when release mem region. Date: Tue, 7 Jan 2020 21:09:41 +0800 Message-Id: <20200107130950.2983-2-Tianyu.Lan@microsoft.com> X-Mailer: git-send-email 2.14.5 In-Reply-To: <20200107130950.2983-1-Tianyu.Lan@microsoft.com> References: <20200107130950.2983-1-Tianyu.Lan@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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