From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f71.google.com (mail-pl0-f71.google.com [209.85.160.71]) by kanga.kvack.org (Postfix) with ESMTP id 0A41A6B005D for ; Sat, 7 Apr 2018 23:37:53 -0400 (EDT) Received: by mail-pl0-f71.google.com with SMTP id u7-v6so4113063plr.13 for ; Sat, 07 Apr 2018 20:37:52 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id j192si9402378pge.291.2018.04.07.20.37.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 07 Apr 2018 20:37:51 -0700 (PDT) From: "Huang, Ying" Subject: [PATCH -mm] mm, pagemap: Fix swap offset value for PMD migration entry Date: Sun, 8 Apr 2018 11:37:37 +0800 Message-Id: <20180408033737.10897-1-ying.huang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Huang Ying , Michal Hocko , "Kirill A. Shutemov" , Andrei Vagin , Dan Williams , Jerome Glisse , Daniel Colascione , Zi Yan , Naoya Horiguchi From: Huang Ying The swap offset reported by /proc//pagemap may be not correct for PMD migration entry. If addr passed into pagemap_range() isn't aligned with PMD start address, the swap offset reported doesn't reflect this. And in the loop to report information of each sub-page, the swap offset isn't increased accordingly as that for PFN. BTW: migration swap entries have PFN information, do we need to restrict whether to show them? Signed-off-by: "Huang, Ying" Cc: Michal Hocko Cc: "Kirill A. Shutemov" Cc: Andrei Vagin Cc: Dan Williams Cc: "Jerome Glisse" Cc: Daniel Colascione Cc: Zi Yan Cc: Naoya Horiguchi --- fs/proc/task_mmu.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 65ae54659833..757e748da613 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1310,9 +1310,11 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION else if (is_swap_pmd(pmd)) { swp_entry_t entry = pmd_to_swp_entry(pmd); + unsigned long offset = swp_offset(entry); + offset += (addr & ~PMD_MASK) >> PAGE_SHIFT; frame = swp_type(entry) | - (swp_offset(entry) << MAX_SWAPFILES_SHIFT); + (offset << MAX_SWAPFILES_SHIFT); flags |= PM_SWAP; if (pmd_swp_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; @@ -1332,6 +1334,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, break; if (pm->show_pfn && (flags & PM_PRESENT)) frame++; + else if (flags | PM_SWAP) + frame += (1 << MAX_SWAPFILES_SHIFT); } spin_unlock(ptl); return err; -- 2.15.1