[03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd

Message ID	20210625013907.PBDZuqY27%akpm@linux-foundation.org
State	New
Headers	show Return-Path: <stable-owner@kernel.org> Date: Thu, 24 Jun 2021 18:39:07 -0700 From: Andrew Morton <akpm@linux-foundation.org> 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 03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd Message-ID: <20210625013907.PBDZuqY27%akpm@linux-foundation.org> In-Reply-To: <20210624183838.ac3161ca4a43989665ac8b2f@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk
Series	[01/24] mm: page_vma_mapped_walk(): use page for pvmw->page \| expand [01/24] mm: page_vma_mapped_walk(): use page for pvmw->page [02/24] mm: page_vma_mapped_walk(): settle PageHuge on entry [03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd [04/24] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block [05/24] mm: page_vma_mapped_walk(): crossing page table boundary [06/24] mm: page_vma_mapped_walk(): add a level of indentation [07/24] mm: page_vma_mapped_walk(): use goto instead of while (1) [08/24] mm: page_vma_mapped_walk(): get vma_address_end() earlier [09/24] mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes [10/24] mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() [15/24] kthread_worker: split code for canceling the delayed work timer [16/24] kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delay... [17/24] mm, futex: fix shared futex pgoff on shmem huge page [18/24] mm/memory-failure: use a mutex to avoid memory_failure() races [19/24] mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned [20/24] mm/hwpoison: do not lock page again when me_huge_page() successfully recovers

Message ID

20210625013907.PBDZuqY27%akpm@linux-foundation.org

State

New

Headers

Date: Thu, 24 Jun 2021 18:39:07 -0700
From: Andrew Morton <akpm@linux-foundation.org>
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 03/24] mm: page_vma_mapped_walk(): use pmde for
 *pvmw->pmd
Message-ID: <20210625013907.PBDZuqY27%akpm@linux-foundation.org>
In-Reply-To: <20210624183838.ac3161ca4a43989665ac8b2f@linux-foundation.org>
User-Agent: s-nail v14.8.16
Precedence: bulk

Series

[01/24] mm: page_vma_mapped_walk(): use page for pvmw->page | expand

Commit Message

Andrew Morton June 25, 2021, 1:39 a.m. UTC

From: Hugh Dickins <hughd@google.com>
Subject: mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd

page_vma_mapped_walk() cleanup: re-evaluate pmde after taking lock, then
use it in subsequent tests, instead of repeatedly dereferencing pointer.

Link: https://lkml.kernel.org/r/53fbc9d-891e-46b2-cb4b-468c3b19238e@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_vma_mapped.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

--- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd
+++ a/mm/page_vma_mapped.c
@@ -191,18 +191,19 @@  restart:
 	pmde = READ_ONCE(*pvmw->pmd);
 	if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
 		pvmw->ptl = pmd_lock(mm, pvmw->pmd);
-		if (likely(pmd_trans_huge(*pvmw->pmd))) {
+		pmde = *pvmw->pmd;
+		if (likely(pmd_trans_huge(pmde))) {
 			if (pvmw->flags & PVMW_MIGRATION)
 				return not_found(pvmw);
-			if (pmd_page(*pvmw->pmd) != page)
+			if (pmd_page(pmde) != page)
 				return not_found(pvmw);
 			return true;
-		} else if (!pmd_present(*pvmw->pmd)) {
+		} 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(*pvmw->pmd))) {
-					swp_entry_t entry = pmd_to_swp_entry(*pvmw->pmd);
+				if (is_migration_entry(pmd_to_swp_entry(pmde))) {
+					swp_entry_t entry = pmd_to_swp_entry(pmde);
 
 					if (migration_entry_to_page(entry) != page)
 						return not_found(pvmw);

[03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd

Commit Message

Patch