From patchwork Fri Jan 22 03:37:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 12038275 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 D8CC3C433E6 for ; Fri, 22 Jan 2021 03:38:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7BEAE2310A for ; Fri, 22 Jan 2021 03:38:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7BEAE2310A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 36D006B0025; Thu, 21 Jan 2021 22:38:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F6D36B0026; Thu, 21 Jan 2021 22:38:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 16F706B0027; Thu, 21 Jan 2021 22:38:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 02CA46B0025 for ; Thu, 21 Jan 2021 22:38:11 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id C422B6118 for ; Fri, 22 Jan 2021 03:38:11 +0000 (UTC) X-FDA: 77732002782.28.kitty84_240e20f27568 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 974DC6D73 for ; Fri, 22 Jan 2021 03:38:11 +0000 (UTC) X-HE-Tag: kitty84_240e20f27568 X-Filterd-Recvd-Size: 8239 Received: from mail-qt1-f180.google.com (mail-qt1-f180.google.com [209.85.160.180]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Fri, 22 Jan 2021 03:38:10 +0000 (UTC) Received: by mail-qt1-f180.google.com with SMTP id c1so3271029qtc.1 for ; Thu, 21 Jan 2021 19:38:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=from:to:subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=5n2Z61YQ/LO6HRNKobWmiWmcOuYkZueXUaF1fevgvMs=; b=PY6VVqi0jkzV/I13PL72rl+9xROWW9CM1xLiOEHtaFP3c64sw9EIlzRLOe9kyqhQiq v0YVgxbUe542ryupmkDe1P37WQaEfYRG/DBqtrAJ2EMXTRspnO0zUwoq4LtmLRBxPW4B VCpWfwXcbGwgoggpG9ehYXfINtjuzrOpUFYKEq5CuE10YMy+8Xq6ImPSdK5QNL1hWgRI UltcXEZkRGTNwSQYekT5dGMPrIpSpNwy/nuSsYYgH+FV9e/A+LDh5XU6klBMzxKknTCS dZYIBuKDQCVLGusbm3r4lQ8TlEyV0K3SL3bfe8Rufkch66MPb6mHhdu/Csd4RaWQO+z/ eeCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=5n2Z61YQ/LO6HRNKobWmiWmcOuYkZueXUaF1fevgvMs=; b=MV/VsM4WB0kVWLFr0kfk/3lGG8ov9LIe8ICXs/M4yuYicB5uwDzIFUxtF01cCR0JWA zwaRkiIkaoMspB9cc1mQc3rQwMX22XuquWgbIn0bvGwZApdt8P9Ct2HDApnZRcLzctZF FIVQR/5NReb6QDw8FG9jNjxnsr9DERvRNpIq4BDsoHbA5FLY4o0IzwGOVe4a1zNuHaho jm2XxEvy9ro1CaqTIyGFuJxxr6wlabC7N9bGCz/sFNfJ9JNzUo9Aod+OzZKeoFU2urBq 5trU4/zwjLMWGerHZxZ4cJc8Zzw1ZSaG1JQdBCswDdAqwCHCp4pOxmKNpYNS2bJIM/IK KUrg== X-Gm-Message-State: AOAM532ARE2E/wKGUxofrWiluihg4F6neYVf+LD9jGz/UyA1esk++zqm XGVtuTxMcUrKyCH+obzKSvA9Mg== X-Google-Smtp-Source: ABdhPJxdwUZjwVe5h1yEIOc0pPlyepebKcCHxJDM6RKigeiNQy4Xu7cZdxixDwOI/SpPmvbDv4NJuw== X-Received: by 2002:ac8:4550:: with SMTP id z16mr2776927qtn.374.1611286690428; Thu, 21 Jan 2021 19:38:10 -0800 (PST) Received: from localhost.localdomain (c-73-69-118-222.hsd1.nh.comcast.net. [73.69.118.222]) by smtp.gmail.com with ESMTPSA id m85sm5426529qke.33.2021.01.21.19.38.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 21 Jan 2021 19:38:09 -0800 (PST) From: Pavel Tatashin To: pasha.tatashin@soleen.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, vbabka@suse.cz, mhocko@suse.com, david@redhat.com, osalvador@suse.de, dan.j.williams@intel.com, sashal@kernel.org, tyhicks@linux.microsoft.com, iamjoonsoo.kim@lge.com, mike.kravetz@oracle.com, rostedt@goodmis.org, mingo@redhat.com, jgg@ziepe.ca, peterz@infradead.org, mgorman@suse.de, willy@infradead.org, rientjes@google.com, jhubbard@nvidia.com, linux-doc@vger.kernel.org, ira.weiny@intel.com, linux-kselftest@vger.kernel.org Subject: [PATCH v7 12/14] mm/gup: longterm pin migration cleanup Date: Thu, 21 Jan 2021 22:37:46 -0500 Message-Id: <20210122033748.924330-13-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210122033748.924330-1-pasha.tatashin@soleen.com> References: <20210122033748.924330-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When pages are longterm pinned, we must migrated them out of movable zone. The function that migrates them has a hidden loop with goto. The loop is to retry on isolation failures, and after successful migration. Make this code better by moving this loop to the caller. Signed-off-by: Pavel Tatashin Reviewed-by: Jason Gunthorpe --- mm/gup.c | 93 ++++++++++++++++++++++---------------------------------- 1 file changed, 37 insertions(+), 56 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index ddbbee741d5d..4a5eed17f451 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1549,27 +1549,28 @@ struct page *get_dump_page(unsigned long addr) #endif /* CONFIG_ELF_CORE */ #ifdef CONFIG_MIGRATION -static long check_and_migrate_movable_pages(struct mm_struct *mm, - unsigned long start, - unsigned long nr_pages, +/* + * Check whether all pages are pinnable, if so return number of pages. If some + * pages are not pinnable, migrate them, and unpin all pages. Return zero if + * pages were migrated, or if some pages were not successfully isolated. + * Return negative error if migration fails. + */ +static long check_and_migrate_movable_pages(unsigned long nr_pages, struct page **pages, - struct vm_area_struct **vmas, unsigned int gup_flags) { - unsigned long i, isolation_error_count; - bool drain_allow; + unsigned long i; + unsigned long isolation_error_count = 0; + bool drain_allow = true; LIST_HEAD(movable_page_list); - long ret = nr_pages; - struct page *prev_head, *head; + long ret = 0; + struct page *prev_head = NULL; + struct page *head; struct migration_target_control mtc = { .nid = NUMA_NO_NODE, .gfp_mask = GFP_USER | __GFP_NOWARN, }; -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) @@ -1609,47 +1610,27 @@ static long check_and_migrate_movable_pages(struct mm_struct *mm, * in the correct zone. */ if (list_empty(&movable_page_list) && !isolation_error_count) - return ret; + return nr_pages; + if (gup_flags & FOLL_PIN) { + unpin_user_pages(pages, nr_pages); + } else { + for (i = 0; i < nr_pages; i++) + put_page(pages[i]); + } if (!list_empty(&movable_page_list)) { - /* - * drop the above get_user_pages reference. - */ - if (gup_flags & FOLL_PIN) - unpin_user_pages(pages, nr_pages); - else - for (i = 0; i < nr_pages; i++) - put_page(pages[i]); - ret = migrate_pages(&movable_page_list, alloc_migration_target, NULL, (unsigned long)&mtc, MIGRATE_SYNC, MR_LONGTERM_PIN); - if (ret) { - if (!list_empty(&movable_page_list)) - putback_movable_pages(&movable_page_list); - return ret > 0 ? -ENOMEM : ret; - } - - /* 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; + if (ret && !list_empty(&movable_page_list)) + putback_movable_pages(&movable_page_list); } - /* - * check again because pages were unpinned, and we also might have - * had isolation errors and need more pages to migrate. - */ - goto check_again; + return ret > 0 ? -ENOMEM : ret; } #else -static long check_and_migrate_movable_pages(struct mm_struct *mm, - unsigned long start, - unsigned long nr_pages, +static long check_and_migrate_movable_pages(unsigned long nr_pages, struct page **pages, - struct vm_area_struct **vmas, unsigned int gup_flags) { return nr_pages; @@ -1667,22 +1648,22 @@ static long __gup_longterm_locked(struct mm_struct *mm, struct vm_area_struct **vmas, unsigned int gup_flags) { - unsigned long flags = 0; + unsigned int flags; long rc; - if (gup_flags & FOLL_LONGTERM) - flags = memalloc_pin_save(); - - rc = __get_user_pages_locked(mm, start, nr_pages, pages, vmas, NULL, - gup_flags); + if (!(gup_flags & FOLL_LONGTERM)) + return __get_user_pages_locked(mm, start, nr_pages, pages, vmas, + NULL, gup_flags); + flags = memalloc_pin_save(); + do { + rc = __get_user_pages_locked(mm, start, nr_pages, pages, vmas, + NULL, gup_flags); + if (rc <= 0) + break; + rc = check_and_migrate_movable_pages(rc, pages, gup_flags); + } while (!rc); + memalloc_pin_restore(flags); - if (gup_flags & FOLL_LONGTERM) { - if (rc > 0) - rc = check_and_migrate_movable_pages(mm, start, rc, - pages, vmas, - gup_flags); - memalloc_pin_restore(flags); - } return rc; }