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=-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=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 5A711C432C3 for ; Thu, 4 Mar 2021 06:18:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2160564EF6 for ; Thu, 4 Mar 2021 06:18:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234944AbhCDGSH (ORCPT ); Thu, 4 Mar 2021 01:18:07 -0500 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:2107 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229602AbhCDGRm (ORCPT ); Thu, 4 Mar 2021 01:17:42 -0500 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 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain 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== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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 { =20 enum ttu_flags { TTU_MIGRATION =3D 0x1, /* migration mode */ - TTU_MUNLOCK =3D 0x2, /* munlock mode */ =20 TTU_SPLIT_HUGE_PMD =3D 0x4, /* split huge PMD if any */ TTU_IGNORE_MLOCK =3D 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, stru= ct vm_area_struct *vma, struct mmu_notifier_range range; enum ttu_flags flags =3D (enum ttu_flags)(long)arg; =20 - /* 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, struc= t vm_area_struct *vma, page_vma_mapped_walk_done(&pvmw); break; } - if (flags & TTU_MUNLOCK) - continue; } =20 /* Unexpected PMD-mapped THP? */ @@ -1775,6 +1769,37 @@ static int page_not_mapped(struct page *page) return !page_mapped(page); }; =20 +static bool try_to_munlock_one(struct page *page, struct vm_area_struct *v= ma, + unsigned long address, void *arg) +{ + struct page_vma_mapped_walk pvmw =3D { + .page =3D page, + .vma =3D vma, + .address =3D 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 =3D { - .rmap_one =3D try_to_unmap_one, - .arg =3D (void *)TTU_MUNLOCK, + .rmap_one =3D try_to_munlock_one, .done =3D page_not_mapped, .anon_lock =3D page_lock_anon_vma_read, =20 --=20 2.20.1