From patchwork Thu Feb 25 02:12:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yinghai Lu X-Patchwork-Id: 8416691 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: patchwork-linux-pci@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C8208C0553 for ; Thu, 25 Feb 2016 02:22:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CCE9920274 for ; Thu, 25 Feb 2016 02:22:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BE0C2034E for ; Thu, 25 Feb 2016 02:22:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759599AbcBYCSx (ORCPT ); Wed, 24 Feb 2016 21:18:53 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:39783 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759479AbcBYCSw (ORCPT ); Wed, 24 Feb 2016 21:18:52 -0500 Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id u1P2Dbst019228 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 25 Feb 2016 02:13:37 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0021.oracle.com (8.13.8/8.13.8) with ESMTP id u1P2DapK016572 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Thu, 25 Feb 2016 02:13:36 GMT Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id u1P2Dajt016770; Thu, 25 Feb 2016 02:13:36 GMT Received: from userv0022.oracle.com (/10.132.126.176) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 24 Feb 2016 18:13:35 -0800 From: Yinghai Lu To: Bjorn Helgaas , David Miller , Benjamin Herrenschmidt , Wei Yang , TJ , Yijing Wang , Khalid Aziz Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yinghai Lu Subject: [PATCH v10 53/59] resources: Make allocate_resource() return best fit resource Date: Wed, 24 Feb 2016 18:12:44 -0800 Message-Id: <1456366370-28995-54-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1456366370-28995-1-git-send-email-yinghai@kernel.org> References: <1456366370-28995-1-git-send-email-yinghai@kernel.org> X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Current code just allocate from first avail window. We can find all suitable empty slots and pick one with smallest size, so we could save the big slot for needed ones later when we have several pci bridges under parent bridge and some bridges get assigned from bios and we need to assign others in kernel. For examples: we have window [0xc0000000, 0xd0000000), and [0xe0000000,0xe1000000) and we try allocate 0x200000 size resource. in this patch will reserve [0xc0000000, 0xd0000000) and [0xe0000000,0xe1000000) at first, then pick [0xe0000000,0xe1000000) to allocate 0x200000 size. Signed-off-by: Yinghai Lu --- kernel/resource.c | 76 ++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 61 insertions(+), 15 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 3d7cf0b..c2724cd 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -589,7 +589,7 @@ static void resource_clip(struct resource *res, resource_size_t min, * alignment constraints */ static int __find_resource(struct resource *root, struct resource *old, - struct resource *new, + struct resource *new, struct resource *availx, resource_size_t size, struct resource_constraint *constraint) { @@ -629,6 +629,11 @@ static int __find_resource(struct resource *root, struct resource *old, if (resource_contains(&avail, &alloc)) { new->start = alloc.start; new->end = alloc.end; + if (availx) { + availx->start = avail.start; + availx->end = avail.end; + availx->flags = avail.flags; + } return 0; } } @@ -643,16 +648,6 @@ next: if (!this || this->end == root->end) return -EBUSY; } -/* - * Find empty slot in the resource tree given range and alignment. - */ -static int find_resource(struct resource *root, struct resource *new, - resource_size_t size, - struct resource_constraint *constraint) -{ - return __find_resource(root, NULL, new, size, constraint); -} - /** * reallocate_resource - allocate a slot in the resource tree given range & alignment. * The resource will be relocated if the new size cannot be reallocated in the @@ -672,8 +667,8 @@ static int reallocate_resource(struct resource *root, struct resource *old, struct resource *conflict; write_lock(&resource_lock); - - if ((err = __find_resource(root, old, &new, newsize, constraint))) + err = __find_resource(root, old, &new, NULL, newsize, constraint); + if (err) goto out; if (resource_contains(&new, old)) { @@ -701,10 +696,16 @@ out: return err; } +struct good_resource { + struct list_head list; + struct resource avail; + struct resource new; +}; /** * allocate_resource - allocate empty slot in the resource tree given range & alignment. - * The resource will be reallocated with a new size if it was already allocated + * The resource will be reallocated with a new size if it was already + * allocated * @root: root resource descriptor * @new: resource descriptor desired by caller * @size: requested resource region size @@ -725,6 +726,9 @@ int allocate_resource(struct resource *root, struct resource *new, { int err; struct resource_constraint constraint; + LIST_HEAD(head); + struct good_resource *good, *tmp; + resource_size_t avail_size = (resource_size_t)-1ULL; if (!alignf) alignf = simple_align_resource; @@ -741,11 +745,53 @@ int allocate_resource(struct resource *root, struct resource *new, return reallocate_resource(root, new, size, &constraint); } + /* find all suitable ones and add to the list */ + for (;;) { + good = kzalloc(sizeof(*good), GFP_KERNEL); + if (!good) { + err = -ENOMEM; + break; + } + + good->new.start = new->start; + good->new.end = new->end; + good->new.flags = new->flags; + + write_lock(&resource_lock); + err = __find_resource(root, NULL, &good->new, &good->avail, + size, &constraint); + if (err || __request_resource(root, &good->avail)) { + err = -EBUSY; + kfree(good); + write_unlock(&resource_lock); + break; + } + write_unlock(&resource_lock); + + list_add(&good->list, &head); + } + + /* pick up the smallest one */ write_lock(&resource_lock); - err = find_resource(root, new, size, &constraint); + list_for_each_entry(good, &head, list) { + if (resource_size(&good->avail) < avail_size) { + avail_size = resource_size(&good->avail); + new->start = good->new.start; + new->end = good->new.end; + err = 0; + } + __release_resource(&good->avail); + } if (err >= 0 && __request_resource(root, new)) err = -EBUSY; write_unlock(&resource_lock); + + /* delete the list */ + list_for_each_entry_safe(good, tmp, &head, list) { + list_del(&good->list); + kfree(good); + } + return err; }