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=-19.1 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, URIBL_BLOCKED,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 D2B36C4360C for ; Mon, 17 May 2021 15:33:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B982961166 for ; Mon, 17 May 2021 15:33:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343768AbhEQPe4 (ORCPT ); Mon, 17 May 2021 11:34:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:53464 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244289AbhEQPT6 (ORCPT ); Mon, 17 May 2021 11:19:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1C4F661C7D; Mon, 17 May 2021 14:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621262041; bh=LkVvnlMpr7KFNdLwKZl+wXiRnEoPowQuRK2r6K5N8X0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZAb+PwsVZXhiTyRZsl1C4RZKT7ZYY4bLK8OzTzvjqsR/I5hg3WvTaeUMXAAdQIkW3 0YW3mXuriG0jDQc0vxS4eT+Ke2SG/xdxhrRFk7towmGl2Ye8A5VjPWU+lLSks6M+aC SncDS0XsdRqtPj5VdoeqLz0C7IxPm1d1mC2vsjf8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Tatashin , Jason Gunthorpe , Dan Williams , David Hildenbrand , David Rientjes , Ingo Molnar , Ira Weiny , James Morris , Jason Gunthorpe , John Hubbard , Joonsoo Kim , Matthew Wilcox , Mel Gorman , Michal Hocko , Michal Hocko , Mike Kravetz , Oscar Salvador , Peter Zijlstra , Sasha Levin , "Steven Rostedt (VMware)" , Tyler Hicks , Vlastimil Babka , Andrew Morton , Linus Torvalds Subject: [PATCH 5.11 207/329] mm/gup: check for isolation errors Date: Mon, 17 May 2021 16:01:58 +0200 Message-Id: <20210517140309.126588576@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210517140302.043055203@linuxfoundation.org> References: <20210517140302.043055203@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pavel Tatashin [ Upstream commit 6e7f34ebb8d25d71ce7f4580ba3cbfc10b895580 ] It is still possible that we pin movable CMA pages if there are isolation errors and cma_page_list stays empty when we check again. Check for isolation errors, and return success only when there are no isolation errors, and cma_page_list is empty after checking. Because isolation errors are transient, we retry indefinitely. Link: https://lkml.kernel.org/r/20210215161349.246722-5-pasha.tatashin@soleen.com Fixes: 9a4e9f3b2d73 ("mm: update get_user_pages_longterm to migrate pages allocated from CMA region") Signed-off-by: Pavel Tatashin Reviewed-by: Jason Gunthorpe Cc: Dan Williams Cc: David Hildenbrand Cc: David Rientjes Cc: Ingo Molnar Cc: Ira Weiny Cc: James Morris Cc: Jason Gunthorpe Cc: John Hubbard Cc: Joonsoo Kim Cc: Matthew Wilcox Cc: Mel Gorman Cc: Michal Hocko Cc: Michal Hocko Cc: Mike Kravetz Cc: Oscar Salvador Cc: Peter Zijlstra Cc: Sasha Levin Cc: Steven Rostedt (VMware) Cc: Tyler Hicks Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/gup.c | 60 ++++++++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 26 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 2d7a567b4056..0cdb93e98d00 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1548,8 +1548,8 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, struct vm_area_struct **vmas, unsigned int gup_flags) { - unsigned long i; - bool drain_allow = true; + unsigned long i, isolation_error_count; + bool drain_allow; LIST_HEAD(cma_page_list); long ret = nr_pages; struct page *prev_head, *head; @@ -1560,6 +1560,8 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, check_again: prev_head = NULL; + isolation_error_count = 0; + drain_allow = true; for (i = 0; i < nr_pages; i++) { head = compound_head(pages[i]); if (head == prev_head) @@ -1571,25 +1573,35 @@ check_again: * of the CMA zone if possible. */ if (is_migrate_cma_page(head)) { - if (PageHuge(head)) - isolate_huge_page(head, &cma_page_list); - else { + if (PageHuge(head)) { + if (!isolate_huge_page(head, &cma_page_list)) + isolation_error_count++; + } else { 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_lru(head), - thp_nr_pages(head)); + if (isolate_lru_page(head)) { + isolation_error_count++; + continue; } + list_add_tail(&head->lru, &cma_page_list); + mod_node_page_state(page_pgdat(head), + NR_ISOLATED_ANON + + page_is_file_lru(head), + thp_nr_pages(head)); } } } + /* + * If list is empty, and no isolation errors, means that all pages are + * in the correct zone. + */ + if (list_empty(&cma_page_list) && !isolation_error_count) + return ret; + if (!list_empty(&cma_page_list)) { /* * drop the above get_user_pages reference. @@ -1609,23 +1621,19 @@ check_again: return ret > 0 ? -ENOMEM : ret; } - /* - * We did migrate all the pages, Try to get the page references - * again migrating any new CMA pages which we failed to isolate - * earlier. - */ - ret = __get_user_pages_locked(mm, start, nr_pages, - pages, vmas, NULL, - gup_flags); - - if (ret > 0) { - nr_pages = ret; - drain_allow = true; - goto check_again; - } + /* We unpinned pages before migration, pin them again */ + ret = __get_user_pages_locked(mm, start, nr_pages, pages, vmas, + NULL, gup_flags); + if (ret <= 0) + return ret; + nr_pages = ret; } - return ret; + /* + * check again because pages were unpinned, and we also might have + * had isolation errors and need more pages to migrate. + */ + goto check_again; } #else static long check_and_migrate_cma_pages(struct mm_struct *mm, -- 2.30.2