From patchwork Fri Jun 25 01:39:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 467800 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=-15.8 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 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 E486FC49EA7 for ; Fri, 25 Jun 2021 01:39:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFFE1613B9 for ; Fri, 25 Jun 2021 01:39:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232995AbhFYBlc (ORCPT ); Thu, 24 Jun 2021 21:41:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:60196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232917AbhFYBlb (ORCPT ); Thu, 24 Jun 2021 21:41:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 45CB5613BA; Fri, 25 Jun 2021 01:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1624585151; bh=LkMc3KPEQZHA+Vv1gO+cu/pm5hDzvAxe+suYMEagwGQ=; h=Date:From:To:Subject:In-Reply-To:From; b=H6MiERQUV/SDhk1l53LqOjJ552XrD/v3euanqOSAXb9Nx9ARMjZsGPlGHgVy/JfEd sBGdrv4nFR7ynF93nDvyyeMlCue9mHlWsnxWhRl6Sf//IbiNvvz+Z3MCx6PLz0ft7S yq0VLasboRsB7+ekCy/YqurO6VeiZF9T2/zVwFEE= Date: Thu, 24 Jun 2021 18:39:10 -0700 From: Andrew Morton To: akpm@linux-foundation.org, apopple@nvidia.com, hughd@google.com, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, peterx@redhat.com, rcampbell@nvidia.com, shy828301@gmail.com, stable@vger.kernel.org, torvalds@linux-foundation.org, wangyugui@e16-tech.com, will@kernel.org, willy@infradead.org, ziy@nvidia.com Subject: [patch 04/24] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block Message-ID: <20210625013910.2BnPsIODO%akpm@linux-foundation.org> In-Reply-To: <20210624183838.ac3161ca4a43989665ac8b2f@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hugh Dickins Subject: mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block page_vma_mapped_walk() cleanup: rearrange the !pmd_present() block to follow the same "return not_found, return not_found, return true" pattern as the block above it (note: returning not_found there is never premature, since existence or prior existence of huge pmd guarantees good alignment). Link: https://lkml.kernel.org/r/378c8650-1488-2edf-9647-32a53cf2e21@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Reviewed-by: Peter Xu Cc: Alistair Popple Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton --- mm/page_vma_mapped.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) --- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-prettify-pvmw_migration-block +++ a/mm/page_vma_mapped.c @@ -198,24 +198,22 @@ restart: if (pmd_page(pmde) != page) return not_found(pvmw); return true; - } else if (!pmd_present(pmde)) { - if (thp_migration_supported()) { - if (!(pvmw->flags & PVMW_MIGRATION)) - return not_found(pvmw); - if (is_migration_entry(pmd_to_swp_entry(pmde))) { - swp_entry_t entry = pmd_to_swp_entry(pmde); + } + if (!pmd_present(pmde)) { + swp_entry_t entry; - if (migration_entry_to_page(entry) != page) - return not_found(pvmw); - return true; - } - } - return not_found(pvmw); - } else { - /* THP pmd was split under us: handle on pte level */ - spin_unlock(pvmw->ptl); - pvmw->ptl = NULL; + if (!thp_migration_supported() || + !(pvmw->flags & PVMW_MIGRATION)) + return not_found(pvmw); + entry = pmd_to_swp_entry(pmde); + if (!is_migration_entry(entry) || + migration_entry_to_page(entry) != page) + return not_found(pvmw); + return true; } + /* THP pmd was split under us: handle on pte level */ + spin_unlock(pvmw->ptl); + pvmw->ptl = NULL; } else if (!pmd_present(pmde)) { /* * If PVMW_SYNC, take and drop THP pmd lock so that we