From patchwork Mon Feb 15 16:13:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pasha Tatashin X-Patchwork-Id: 12088895 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 0587FC4332B for ; Mon, 15 Feb 2021 16:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD0AA64DF0 for ; Mon, 15 Feb 2021 16:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231682AbhBOQVy (ORCPT ); Mon, 15 Feb 2021 11:21:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232645AbhBOQSa (ORCPT ); Mon, 15 Feb 2021 11:18:30 -0500 Received: from mail-qt1-x831.google.com (mail-qt1-x831.google.com [IPv6:2607:f8b0:4864:20::831]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 530BEC061A32 for ; Mon, 15 Feb 2021 08:14:11 -0800 (PST) Received: by mail-qt1-x831.google.com with SMTP id e11so5147285qtg.6 for ; Mon, 15 Feb 2021 08:14:11 -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=QmoVsr7V/2HMMUlT3knKDmL5f3XKOtKg0eH1O4Q+2cw=; b=VINf+kX7XPpEXKir9xWLfgP23fkqUGexISZo96tV848K8Ct0HPPuxDrytkIdwshB9q wST75ooR0nwc6uI66/2ABb+uB7I/4GU35ZaZu7qgAtWWnH1hgUmE8+ylSkxS8cNHswdc Pt6bzcK0apK64B+6FmGF9SrnIvlR2tDlmusUOGQsmKk82YmTTJaPm3BnAHtBtD5cmaaQ UVWy6FFUba4kzc/hTM1LZdM0kfgvR/kH/xSsoIh/OiqK0C7MH3yV03VJOjyNCEowQQcR OujN6fgH+3Yullwus/picqet+hSc+EqPSUzk5hzfIJktRjYRbHLLGWctSscvg418ghgR j1yg== 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=QmoVsr7V/2HMMUlT3knKDmL5f3XKOtKg0eH1O4Q+2cw=; b=oEJdnmgtf3rdN5c1IV/3SXRpW6Vd6+uPAmmMivMhGiVVxPir+6W4mq5rXB+E6IVwTH kQeJ1OxqBlEmP8shWQZiYI/1+0xo76qysXXZkquTutzY6OL6awZLHendq1iq9Cn2gn8y R34GlIS6xoOBD97poa0QyADaBX1nTH6SNydwl/2qxpF9h5JNrMX0Xaew59+k2Ff9juk3 97kxbgbLNlic1MJXtW6uv0vICVq9E4tKEo+0w6dys/UNhAT52L49tN3D+uE3U4q/ofj2 ssFfV07D/ft/HPyhzWUOs+lvPlAZXY1epyzcETd5GpRqF6uIt75Q5zJx9fZ3bLXEyO7a TzyQ== X-Gm-Message-State: AOAM530DlZO/u2+FySiLJciEI9sp/VtfFphLEfoZCdrTdg0xWhWW8gqM gcYzVbxRTphHmZZeijfI64QrSg== X-Google-Smtp-Source: ABdhPJzXiJ2mjn2gSGrc+eJpTs9TzmvlyrbhTg4dXgWp/dMT8mWJeCc2GMlBCtxlFza/Y1oyAHMUCQ== X-Received: by 2002:ac8:538a:: with SMTP id x10mr14123307qtp.166.1613405650445; Mon, 15 Feb 2021 08:14:10 -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 u7sm10909213qta.75.2021.02.15.08.14.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Feb 2021 08:14:09 -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, jmorris@namei.org Subject: [PATCH v11 12/14] mm/gup: longterm pin migration cleanup Date: Mon, 15 Feb 2021 11:13:47 -0500 Message-Id: <20210215161349.246722-13-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210215161349.246722-1-pasha.tatashin@soleen.com> References: <20210215161349.246722-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org 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 fab20b934030..905d550abb91 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1542,27 +1542,28 @@ 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) @@ -1600,47 +1601,27 @@ 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; @@ -1658,22 +1639,22 @@ 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; }