From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752472AbeDHDhw (ORCPT ); Sat, 7 Apr 2018 23:37:52 -0400 Received: from mga11.intel.com ([192.55.52.93]:32328 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752202AbeDHDhv (ORCPT ); Sat, 7 Apr 2018 23:37:51 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,421,1517904000"; d="scan'208";a="44997746" From: "Huang, Ying" 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 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> X-Mailer: git-send-email 2.15.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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