From: Mel Gorman <mgorman@suse.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Alex Thorlton <athorlton@sgi.com>, Rik van Riel <riel@redhat.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>
Subject: [PATCH 05/18] mm: numa: Do not clear PTE for pte_numa update
Date: Mon, 9 Dec 2013 07:08:59 +0000 [thread overview]
Message-ID: <1386572952-1191-6-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1386572952-1191-1-git-send-email-mgorman@suse.de>
The TLB must be flushed if the PTE is updated but change_pte_range is clearing
the PTE while marking PTEs pte_numa without necessarily flushing the TLB if it
reinserts the same entry. Without the flush, it's conceivable that two processors
have different TLBs for the same virtual address and at the very least it would
generate spurious faults. This patch only unmaps the pages in change_pte_range for
a full protection change.
Cc: stable@vger.kernel.org
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/mprotect.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 2666797..0a07e2d 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -52,13 +52,14 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
pte_t ptent;
bool updated = false;
- ptent = ptep_modify_prot_start(mm, addr, pte);
if (!prot_numa) {
+ ptent = ptep_modify_prot_start(mm, addr, pte);
ptent = pte_modify(ptent, newprot);
updated = true;
} else {
struct page *page;
+ ptent = *pte;
page = vm_normal_page(vma, addr, oldpte);
if (page) {
if (!pte_numa(oldpte)) {
@@ -79,7 +80,10 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
if (updated)
pages++;
- ptep_modify_prot_commit(mm, addr, pte, ptent);
+
+ /* Only !prot_numa always clears the pte */
+ if (!prot_numa)
+ ptep_modify_prot_commit(mm, addr, pte, ptent);
} else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);
--
1.8.4
--
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next prev parent reply other threads:[~2013-12-09 7:09 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-09 7:08 [PATCH 00/18] NUMA balancing segmentation fault fixes and misc followups v3 Mel Gorman
2013-12-09 7:08 ` [PATCH 01/18] mm: numa: Serialise parallel get_user_page against THP migration Mel Gorman
2013-12-09 14:08 ` Rik van Riel
2013-12-09 7:08 ` [PATCH 02/18] mm: numa: Call MMU notifiers on " Mel Gorman
2013-12-09 14:09 ` Rik van Riel
2013-12-09 7:08 ` [PATCH 03/18] mm: Clear pmd_numa before invalidating Mel Gorman
2013-12-09 14:14 ` Rik van Riel
2013-12-09 7:08 ` [PATCH 04/18] mm: numa: Do not clear PMD during PTE update scan Mel Gorman
2013-12-09 14:22 ` Rik van Riel
2013-12-09 7:08 ` Mel Gorman [this message]
2013-12-09 14:31 ` [PATCH 05/18] mm: numa: Do not clear PTE for pte_numa update Rik van Riel
2013-12-09 7:09 ` [PATCH 06/18] mm: numa: Ensure anon_vma is locked to prevent parallel THP splits Mel Gorman
2013-12-09 14:34 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 07/18] mm: numa: Avoid unnecessary work on the failure path Mel Gorman
2013-12-09 14:42 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 08/18] sched: numa: Skip inaccessible VMAs Mel Gorman
2013-12-09 14:50 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 09/18] mm: numa: Clear numa hinting information on mprotect Mel Gorman
2013-12-09 15:57 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 10/18] mm: numa: Avoid unnecessary disruption of NUMA hinting during migration Mel Gorman
2013-12-09 16:10 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 11/18] mm: fix TLB flush race between migration, and change_protection_range Mel Gorman
2013-12-10 14:25 ` Rik van Riel
2013-12-10 17:19 ` Mel Gorman
2013-12-10 18:02 ` Paul E. McKenney
2013-12-11 11:21 ` Mel Gorman
2013-12-09 7:09 ` [PATCH 12/18] mm: numa: Defer TLB flush for THP migration as long as possible Mel Gorman
2013-12-09 16:13 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 13/18] mm: numa: Make NUMA-migrate related functions static Mel Gorman
2013-12-09 7:20 ` Wanpeng Li
[not found] ` <20131209072010.GA3716@hacker.(null)>
2013-12-09 8:46 ` Mel Gorman
2013-12-09 8:57 ` Wanpeng Li
[not found] ` <20131209085720.GA16251@hacker.(null)>
2013-12-09 9:08 ` Mel Gorman
2013-12-09 9:13 ` Wanpeng Li
2013-12-09 16:14 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 14/18] mm: numa: Limit scope of lock for NUMA migrate rate limiting Mel Gorman
2013-12-09 16:47 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 15/18] mm: numa: Trace tasks that fail migration due to " Mel Gorman
2013-12-09 16:57 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 16/18] mm: numa: Do not automatically migrate KSM pages Mel Gorman
2013-12-09 16:57 ` Rik van Riel
2013-12-09 7:09 ` [PATCH 17/18] sched: Tracepoint task movement Mel Gorman
2013-12-09 18:54 ` Rik van Riel
2013-12-10 8:42 ` Mel Gorman
2013-12-10 9:06 ` Andrew Jones
2013-12-09 7:09 ` [PATCH 18/18] sched: Add tracepoints related to NUMA task migration Mel Gorman
2013-12-09 19:06 ` Rik van Riel
-- strict thread matches above, loose matches on Subject: below --
2013-12-10 15:51 [PATCH 00/17] NUMA balancing segmentation fault fixes and misc followups v4 Mel Gorman
2013-12-10 15:51 ` [PATCH 05/18] mm: numa: Do not clear PTE for pte_numa update Mel Gorman
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