From patchwork Thu Mar 4 06:16:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alistair Popple X-Patchwork-Id: 12115527 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,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=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 EF7C9C433E0 for ; Thu, 4 Mar 2021 06:17:04 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8A23F64EFE for ; Thu, 4 Mar 2021 06:17:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A23F64EFE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2E2E06B0008; Thu, 4 Mar 2021 01:17:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 294856B000A; Thu, 4 Mar 2021 01:17:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 15AAB6B000C; Thu, 4 Mar 2021 01:17:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0200.hostedemail.com [216.40.44.200]) by kanga.kvack.org (Postfix) with ESMTP id EFA386B0008 for ; Thu, 4 Mar 2021 01:17:03 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id B60978418 for ; Thu, 4 Mar 2021 06:17:03 +0000 (UTC) X-FDA: 77881183926.03.23AC76E Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf22.hostedemail.com (Postfix) with ESMTP id 5C775C0001EA for ; Thu, 4 Mar 2021 06:17:02 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Wed, 03 Mar 2021 22:17:02 -0800 Received: from DRHQMAIL107.nvidia.com (10.27.9.16) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Mar 2021 06:17:01 +0000 Received: from localhost (172.20.145.6) by DRHQMAIL107.nvidia.com (10.27.9.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Mar 2021 06:17:00 +0000 From: Alistair Popple To: , , , CC: , , , , , , , "Alistair Popple" Subject: [PATCH v4 3/8] mm/rmap: Split try_to_munlock from try_to_unmap Date: Thu, 4 Mar 2021 17:16:40 +1100 Message-ID: <20210304061645.29747-4-apopple@nvidia.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210304061645.29747-1-apopple@nvidia.com> References: <20210304061645.29747-1-apopple@nvidia.com> MIME-Version: 1.0 X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To DRHQMAIL107.nvidia.com (10.27.9.16) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1614838622; bh=KhCqKR0s83WdeI+iaFfhkOL/c6bb31bkOEArZ0mdKmM=; h=From:To:CC:Subject:Date:Message-ID:X-Mailer:In-Reply-To: References:MIME-Version:Content-Transfer-Encoding:Content-Type: X-Originating-IP:X-ClientProxiedBy; b=MOGHUVtTdTRRnVM9gq94Dmwzipq4DKEWU/oA5LYFxDM6ZX7YA7eQkrYk885jNhfmF QSnXbyP2K2L9gjAjZ1ZRl+n1UeWMB3mfjslAiwyZfOEW9Moef7fhJprzMz2l8c9uv2 48AEU0/URU0e+PsBkP7Nsh6GCWY31yOCGPt8WJdFSeYFmweKhfS4MidD0tnjz5d485 XjgxMRleBYOPNPkul1FcBHZjn9hSJhTwQIiE3Lhn4aGWjgqamRpWU7BwR7KGEnfHkS xWBEdw+c9HUoPWfjMQ5IevGfoVotudK8WtNfH+uSUTyfKCqYP8Xt4lccSnBa26xAZR dPdBgvENXe0oA== X-Stat-Signature: pta8jky8wh5phxei4z9rdo77zdj7kzk7 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 5C775C0001EA Received-SPF: none (nvidia.com>: No applicable sender policy available) receiver=imf22; identity=mailfrom; envelope-from=""; helo=hqnvemgate24.nvidia.com; client-ip=216.228.121.143 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614838622-733375 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: The behaviour of try_to_unmap_one() is difficult to follow because it performs different operations based on a fairly large set of flags used in different combinations. TTU_MUNLOCK is one such flag. However it is exclusively used by try_to_munlock() which specifies no other flags. Therefore rather than overload try_to_unmap_one() with unrelated behaviour split this out into it's own function and remove the flag. Signed-off-by: Alistair Popple Reviewed-by: Ralph Campbell --- Christoph - I didn't add your Reviewed-by because removal of the extra VM_LOCKED check changed things slightly. Let me know if you're still ok for me to add it. Thanks. v4: * Removed redundant check for VM_LOCKED --- include/linux/rmap.h | 1 - mm/rmap.c | 40 ++++++++++++++++++++++++++++++++-------- 2 files changed, 32 insertions(+), 9 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 70085ca1a3fc..7f1ee411bd7b 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -87,7 +87,6 @@ struct anon_vma_chain { enum ttu_flags { TTU_MIGRATION = 0x1, /* migration mode */ - TTU_MUNLOCK = 0x2, /* munlock mode */ TTU_SPLIT_HUGE_PMD = 0x4, /* split huge PMD if any */ TTU_IGNORE_MLOCK = 0x8, /* ignore mlock */ diff --git a/mm/rmap.c b/mm/rmap.c index ef9ef2694c58..c8a637abffb3 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1391,10 +1391,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, struct mmu_notifier_range range; enum ttu_flags flags = (enum ttu_flags)(long)arg; - /* munlock has nothing to gain from examining un-locked vmas */ - if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED)) - return true; - if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION) && is_zone_device_page(page) && !is_device_private_page(page)) return true; @@ -1455,8 +1451,6 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, page_vma_mapped_walk_done(&pvmw); break; } - if (flags & TTU_MUNLOCK) - continue; } /* Unexpected PMD-mapped THP? */ @@ -1775,6 +1769,37 @@ static int page_not_mapped(struct page *page) return !page_mapped(page); }; +static bool try_to_munlock_one(struct page *page, struct vm_area_struct *vma, + unsigned long address, void *arg) +{ + struct page_vma_mapped_walk pvmw = { + .page = page, + .vma = vma, + .address = address, + }; + + /* munlock has nothing to gain from examining un-locked vmas */ + if (!(vma->vm_flags & VM_LOCKED)) + return true; + + while (page_vma_mapped_walk(&pvmw)) { + /* PTE-mapped THP are never mlocked */ + if (!PageTransCompound(page)) { + /* + * Holding pte lock, we do *not* need + * mmap_lock here + */ + mlock_vma_page(page); + } + page_vma_mapped_walk_done(&pvmw); + + /* found a mlocked page, no point continuing munlock check */ + return false; + } + + return true; +} + /** * try_to_munlock - try to munlock a page * @page: the page to be munlocked @@ -1787,8 +1812,7 @@ static int page_not_mapped(struct page *page) void try_to_munlock(struct page *page) { struct rmap_walk_control rwc = { - .rmap_one = try_to_unmap_one, - .arg = (void *)TTU_MUNLOCK, + .rmap_one = try_to_munlock_one, .done = page_not_mapped, .anon_lock = page_lock_anon_vma_read,