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=-19.0 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,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 C9D7CC433E6 for ; Tue, 12 Jan 2021 16:14:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89C7A20738 for ; Tue, 12 Jan 2021 16:14:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392700AbhALQOT (ORCPT ); Tue, 12 Jan 2021 11:14:19 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:41458 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392677AbhALQOS (ORCPT ); Tue, 12 Jan 2021 11:14:18 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 10CG9Jf5181290; Tue, 12 Jan 2021 16:13:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2020-01-29; bh=Uq1JZwlc7rQdJHDzbMM8eEoxBWrKCftQkfYhyUm6RdQ=; b=pJgS2zsW3b3GIOHbVzd+vHv/SIO1h5xI3yq2zpy/Z02f+K2fmMkdC/RXj95hzcb9t6VZ klQJtjkk8bxZ+QYS1Or+DtvKL9thadmB0Ld5V45QPCggsF97bKG/T5b6lCHTiCu5H85Y 0O06yfEJU1E7SoOSOUQE/FJNjesqDU5XD4bD8nk+Bkyl4X7FMiW3zP3ShvsWYfd9zx1l BbT8oRg83NMFlhP1GRnV793/8yH9Pox1a/zbklqOYfWRstsIwlqVx7S8lJRVeXftkUC3 dxRenM8ASQs0XGoaH8jC4YasS8Jxm0ykukJlVqlvpscNw+3gLevEmGTgNNEzul7AvhZx 3Q== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 360kvjy1je-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jan 2021 16:13:13 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 10CGA1bY094411; Tue, 12 Jan 2021 16:13:12 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 360key11vu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Jan 2021 16:13:12 +0000 Received: from abhmp0012.oracle.com (abhmp0012.oracle.com [141.146.116.18]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 10CGDBju029893; Tue, 12 Jan 2021 16:13:11 GMT Received: from revolver.jebus.ca (/23.233.25.87) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 Jan 2021 08:13:10 -0800 From: "Liam R. Howlett" To: maple-tree@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrew Morton , Song Liu , Davidlohr Bueso , "Paul E . McKenney" , Matthew Wilcox , Jerome Glisse , David Rientjes , Axel Rasmussen , Suren Baghdasaryan , Vlastimil Babka , Rik van Riel , Peter Zijlstra Subject: [PATCH v2 10/70] mm/mmap: Change unmapped_area and unmapped_area_topdown to use maple tree Date: Tue, 12 Jan 2021 11:11:40 -0500 Message-Id: <20210112161240.2024684-11-Liam.Howlett@Oracle.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210112161240.2024684-1-Liam.Howlett@Oracle.com> References: <20210112161240.2024684-1-Liam.Howlett@Oracle.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9862 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 malwarescore=0 suspectscore=0 adultscore=0 spamscore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101120092 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9862 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 phishscore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 malwarescore=0 clxscore=1015 impostorscore=0 spamscore=0 mlxscore=0 suspectscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2101120092 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use the new maple tree data structure to find an unmapped area. Signed-off-by: Liam R. Howlett --- mm/mmap.c | 249 ++++++------------------------------------------------ 1 file changed, 27 insertions(+), 222 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index f123f9c97dfe8..3b3084ee309b7 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2040,260 +2040,65 @@ unsigned long mmap_region(struct file *file, unsigned long addr, return error; } +/* unmapped_area() Find an area between the low_limit and the high_limit with + * the correct alignment and offset, all from @info. Note: current->mm is used + * for the search. + * + * @info: The unmapped area information including the range (low_limit - + * hight_limit), the alignment offset and mask. + * + * Return: A memory address or -ENOMEM. + */ static unsigned long unmapped_area(struct vm_unmapped_area_info *info) { - /* - * We implement the search by looking for an rbtree node that - * immediately follows a suitable gap. That is, - * - gap_start = vma->vm_prev->vm_end <= info->high_limit - length; - * - gap_end = vma->vm_start >= info->low_limit + length; - * - gap_end - gap_start >= length - */ + unsigned long length, gap; - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - unsigned long length, low_limit, high_limit, gap_start, gap_end; - unsigned long gap; + MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); + validate_mm(current->mm); - MA_STATE(mas, &mm->mm_mt, 0, 0); /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; if (length < info->length) return -ENOMEM; - - /* Maple tree is self contained. */ - rcu_read_lock(); if (mas_get_empty_area(&mas, info->low_limit, info->high_limit - 1, length)) { rcu_read_unlock(); return -ENOMEM; } - rcu_read_unlock(); gap = mas.index; gap += (info->align_offset - gap) & info->align_mask; - - /* Adjust search limits by the desired length */ - if (info->high_limit < length) - return -ENOMEM; - high_limit = info->high_limit - length; - - if (info->low_limit > high_limit) - return -ENOMEM; - low_limit = info->low_limit + length; - - /* Check if rbtree root looks promising */ - if (RB_EMPTY_ROOT(&mm->mm_rb)) - goto check_highest; - vma = rb_entry(mm->mm_rb.rb_node, struct vm_area_struct, vm_rb); - if (vma->rb_subtree_gap < length) - goto check_highest; - - while (true) { - /* Visit left subtree if it looks promising */ - gap_end = vm_start_gap(vma); - if (gap_end >= low_limit && vma->vm_rb.rb_left) { - struct vm_area_struct *left = - rb_entry(vma->vm_rb.rb_left, - struct vm_area_struct, vm_rb); - if (left->rb_subtree_gap >= length) { - vma = left; - continue; - } - } - - gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; -check_current: - /* Check if current node has a suitable gap */ - if (gap_start > high_limit) - return -ENOMEM; - if (gap_end >= low_limit && - gap_end > gap_start && gap_end - gap_start >= length) - goto found; - - /* Visit right subtree if it looks promising */ - if (vma->vm_rb.rb_right) { - struct vm_area_struct *right = - rb_entry(vma->vm_rb.rb_right, - struct vm_area_struct, vm_rb); - if (right->rb_subtree_gap >= length) { - vma = right; - continue; - } - } - - /* Go back up the rbtree to find next candidate node */ - while (true) { - struct rb_node *prev = &vma->vm_rb; - if (!rb_parent(prev)) - goto check_highest; - vma = rb_entry(rb_parent(prev), - struct vm_area_struct, vm_rb); - if (prev == vma->vm_rb.rb_left) { - gap_start = vm_end_gap(vma->vm_prev); - gap_end = vm_start_gap(vma); - goto check_current; - } - } - } - -check_highest: - /* Check highest gap, which does not precede any rbtree node */ - gap_start = mm->highest_vm_end; - gap_end = ULONG_MAX; /* Only for VM_BUG_ON below */ - if (gap_start > high_limit) - return -ENOMEM; - -found: - /* We found a suitable gap. Clip it with the original low_limit. */ - if (gap_start < info->low_limit) - gap_start = info->low_limit; - - /* Adjust gap address to the desired alignment */ - gap_start += (info->align_offset - gap_start) & info->align_mask; - - VM_BUG_ON(gap_start + info->length > info->high_limit); - VM_BUG_ON(gap_start + info->length > gap_end); - - VM_BUG_ON(gap != gap_start); - return gap_start; + return gap; } +/* unmapped_area() Find an area between the low_limit and the high_limit with + * the correct alignment and offset at the highest available address, all from + * @info. Note: current->mm is used for the search. + * + * @info: The unmapped area information including the range (low_limit - + * hight_limit), the alignment offset and mask. + * + * Return: A memory address or -ENOMEM. + */ static unsigned long unmapped_area_topdown(struct vm_unmapped_area_info *info) { - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma = NULL; - unsigned long length, low_limit, high_limit, gap_start, gap_end; - unsigned long gap; + unsigned long length, gap; - MA_STATE(mas, &mm->mm_mt, 0, 0); - validate_mm_mt(mm); + MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); + validate_mm_mt(current->mm); /* Adjust search length to account for worst case alignment overhead */ length = info->length + info->align_mask; if (length < info->length) return -ENOMEM; - rcu_read_lock(); - if (mas_get_empty_area_rev(&mas, info->low_limit, info->high_limit, + if (mas_get_empty_area_rev(&mas, info->low_limit, info->high_limit - 1, length)) { rcu_read_unlock(); return -ENOMEM; } - rcu_read_unlock(); gap = (mas.index + info->align_mask) & ~info->align_mask; gap -= info->align_offset & info->align_mask; - /* - * Adjust search limits by the desired length. - * See implementation comment at top of unmapped_area(). - */ - gap_end = info->high_limit; - if (gap_end < length) - return -ENOMEM; - high_limit = gap_end - length; - - if (info->low_limit > high_limit) - return -ENOMEM; - low_limit = info->low_limit + length; - - /* Check highest gap, which does not precede any rbtree node */ - gap_start = mm->highest_vm_end; - if (gap_start <= high_limit) - goto found_highest; - - /* Check if rbtree root looks promising */ - if (RB_EMPTY_ROOT(&mm->mm_rb)) - return -ENOMEM; - vma = rb_entry(mm->mm_rb.rb_node, struct vm_area_struct, vm_rb); - if (vma->rb_subtree_gap < length) - return -ENOMEM; - - while (true) { - /* Visit right subtree if it looks promising */ - gap_start = vma->vm_prev ? vm_end_gap(vma->vm_prev) : 0; - if (gap_start <= high_limit && vma->vm_rb.rb_right) { - struct vm_area_struct *right = - rb_entry(vma->vm_rb.rb_right, - struct vm_area_struct, vm_rb); - if (right->rb_subtree_gap >= length) { - vma = right; - continue; - } - } - -check_current: - /* Check if current node has a suitable gap */ - gap_end = vm_start_gap(vma); - if (gap_end < low_limit) - return -ENOMEM; - if (gap_start <= high_limit && - gap_end > gap_start && gap_end - gap_start >= length) - goto found; - - /* Visit left subtree if it looks promising */ - if (vma->vm_rb.rb_left) { - struct vm_area_struct *left = - rb_entry(vma->vm_rb.rb_left, - struct vm_area_struct, vm_rb); - if (left->rb_subtree_gap >= length) { - vma = left; - continue; - } - } - - /* Go back up the rbtree to find next candidate node */ - while (true) { - struct rb_node *prev = &vma->vm_rb; - if (!rb_parent(prev)) - return -ENOMEM; - vma = rb_entry(rb_parent(prev), - struct vm_area_struct, vm_rb); - if (prev == vma->vm_rb.rb_right) { - gap_start = vma->vm_prev ? - vm_end_gap(vma->vm_prev) : 0; - goto check_current; - } - } - } - -found: - /* We found a suitable gap. Clip it with the original high_limit. */ - if (gap_end > info->high_limit) - gap_end = info->high_limit; - -found_highest: - /* Compute highest gap address at the desired alignment */ - gap_end -= info->length; - gap_end -= (gap_end - info->align_offset) & info->align_mask; - - VM_BUG_ON(gap_end < info->low_limit); - VM_BUG_ON(gap_end < gap_start); - - if (gap != gap_end) { - pr_err("%s: %px Gap was found: mt %lu gap_end %lu\n", __func__, - mm, gap, gap_end); - pr_err("window was %lu - %lu size %lu\n", info->high_limit, - info->low_limit, length); - pr_err("mas.min %lu max %lu mas.last %lu\n", mas.min, mas.max, - mas.last); - pr_err("mas.index %lu align mask %lu offset %lu\n", mas.index, - info->align_mask, info->align_offset); - pr_err("rb_find_vma find on %lu => %px (%px)\n", mas.index, - find_vma(mm, mas.index), vma); -#if defined(CONFIG_DEBUG_MAPLE_TREE) - mt_dump(&mm->mm_mt); -#endif - { - struct vm_area_struct *dv = mm->mmap; - - while (dv) { - printk("vma %px %lu-%lu\n", dv, dv->vm_start, dv->vm_end); - dv = dv->vm_next; - } - } - VM_BUG_ON(gap != gap_end); - } - - return gap_end; + return gap; } /* -- 2.28.0