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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,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 AE509C433F5 for ; Thu, 6 Sep 2018 05:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5106220659 for ; Thu, 6 Sep 2018 05:44:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5106220659 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726597AbeIFKRt (ORCPT ); Thu, 6 Sep 2018 06:17:49 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47584 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbeIFKRs (ORCPT ); Thu, 6 Sep 2018 06:17:48 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w865hf3J099935 for ; Thu, 6 Sep 2018 01:44:04 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2max9x830p-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 06 Sep 2018 01:44:04 -0400 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 6 Sep 2018 01:43:59 -0400 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w865hw5X46989384 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 6 Sep 2018 05:43:58 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CCB6A124058; Thu, 6 Sep 2018 02:44:27 -0400 (EDT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 78042124055; Thu, 6 Sep 2018 02:44:25 -0400 (EDT) Received: from skywalker.ibmuc.com (unknown [9.102.0.183]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 6 Sep 2018 02:44:25 -0400 (EDT) From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, Alexey Kardashevskiy , mpe@ellerman.id.au Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [RFC PATCH V2 2/4] mm: Add get_user_pages_cma_migrate Date: Thu, 6 Sep 2018 11:13:40 +0530 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180906054342.25094-1-aneesh.kumar@linux.ibm.com> References: <20180906054342.25094-1-aneesh.kumar@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18090605-2213-0000-0000-000002E8E385 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009676; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01084227; UDB=6.00559595; IPR=6.00864226; MB=3.00023138; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-06 05:44:01 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18090605-2214-0000-0000-00005B754B87 Message-Id: <20180906054342.25094-2-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-06_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1809060061 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This helper does a get_user_pages_fast and if it find pages in the CMA area it will try to migrate them before taking page reference. This makes sure that we don't keep non-movable pages (due to page reference count) in the CMA area. Not able to move pages out of CMA area result in CMA allocation failures. Signed-off-by: Aneesh Kumar K.V --- include/linux/migrate.h | 3 ++ mm/migrate.c | 108 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 111 insertions(+) diff --git a/include/linux/migrate.h b/include/linux/migrate.h index f2b4abbca55e..d82b35afd2eb 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -286,6 +286,9 @@ static inline int migrate_vma(const struct migrate_vma_ops *ops, } #endif /* IS_ENABLED(CONFIG_MIGRATE_VMA_HELPER) */ +extern int get_user_pages_cma_migrate(unsigned long start, int nr_pages, int write, + struct page **pages); + #endif /* CONFIG_MIGRATION */ #endif /* _LINUX_MIGRATE_H */ diff --git a/mm/migrate.c b/mm/migrate.c index c27e97b5b69d..c26288d407ae 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -3008,3 +3008,111 @@ int migrate_vma(const struct migrate_vma_ops *ops, } EXPORT_SYMBOL(migrate_vma); #endif /* defined(MIGRATE_VMA_HELPER) */ + +static struct page *new_non_cma_page(struct page *page, unsigned long private) +{ + /* + * We want to make sure we allocate the new page from the same node + * as the source page. + */ + int nid = page_to_nid(page); + gfp_t gfp_mask = GFP_USER | __GFP_THISNODE; + + if (PageHighMem(page)) + gfp_mask |= __GFP_HIGHMEM; + + if (PageHuge(page)) { + + struct hstate *h = page_hstate(page); + /* + * We don't want to dequeue from the pool because pool pages will + * mostly be from the CMA region. + */ + return alloc_migrate_huge_page(h, gfp_mask, nid, NULL); + + } else if (PageTransHuge(page)) { + struct page *thp; + gfp_t thp_gfpmask = GFP_TRANSHUGE | __GFP_THISNODE; + + /* + * Remove the movable mask so that we don't allocate from + * CMA area again. + */ + thp_gfpmask &= ~__GFP_MOVABLE; + thp = __alloc_pages_node(nid, thp_gfpmask, HPAGE_PMD_ORDER); + if (!thp) + return NULL; + prep_transhuge_page(thp); + return thp; + } + + return __alloc_pages_node(nid, gfp_mask, 0); +} + +int get_user_pages_cma_migrate(unsigned long start, int nr_pages, int write, + struct page **pages) +{ + int i, ret; + bool drain_allow = true; + bool migrate_allow = true; + LIST_HEAD(cma_page_list); + +get_user_again: + ret = get_user_pages_fast(start, nr_pages, write, pages); + if (ret <= 0) + return ret; + + for (i = 0; i < ret; ++i) { + /* + * If we get a page from the CMA zone, since we are going to + * be pinning these entries, we might as well move them out + * of the CMA zone if possible. + */ + if (is_migrate_cma_page(pages[i]) && migrate_allow) { + if (PageHuge(pages[i])) + isolate_huge_page(pages[i], &cma_page_list); + else { + struct page *head = compound_head(pages[i]); + + if (!PageLRU(head) && drain_allow) { + lru_add_drain_all(); + drain_allow = false; + } + + if (!isolate_lru_page(head)) { + list_add_tail(&head->lru, &cma_page_list); + mod_node_page_state(page_pgdat(head), + NR_ISOLATED_ANON + + page_is_file_cache(head), + hpage_nr_pages(head)); + } + } + } + } + if (!list_empty(&cma_page_list)) { + /* + * drop the above get_user_pages reference. + */ + for (i = 0; i < ret; ++i) + put_page(pages[i]); + + if (migrate_pages(&cma_page_list, new_non_cma_page, + NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE)) { + /* + * some of the pages failed migration. Do get_user_pages + * without migration. + */ + migrate_allow = false; + + if (!list_empty(&cma_page_list)) + putback_movable_pages(&cma_page_list); + } + /* + * We did migrate all the pages, Try to get the page references again + * migrating any new CMA pages which we failed to isolate earlier. + */ + drain_allow = true; + goto get_user_again; + } + return ret; +} -- 2.17.1