[3.8.y.z extended stable] Patch "mm: numa: Sanitize task_numa_fault() callsites" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Fri Nov 8 02:08:22 UTC 2013
This is a note to let you know that I have just added a patch titled
mm: numa: Sanitize task_numa_fault() callsites
to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue
This patch is scheduled to be released in version 3.8.13.13.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From b146128c397f57f1142e7667aed24a356ceb822b Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman at suse.de>
Date: Mon, 7 Oct 2013 11:28:45 +0100
Subject: mm: numa: Sanitize task_numa_fault() callsites
commit c61109e34f60f6e85bb43c5a1cd51c0e3db40847 upstream.
There are three callers of task_numa_fault():
- do_huge_pmd_numa_page():
Accounts against the current node, not the node where the
page resides, unless we migrated, in which case it accounts
against the node we migrated to.
- do_numa_page():
Accounts against the current node, not the node where the
page resides, unless we migrated, in which case it accounts
against the node we migrated to.
- do_pmd_numa_page():
Accounts not at all when the page isn't migrated, otherwise
accounts against the node we migrated towards.
This seems wrong to me; all three sites should have the same
sementaics, furthermore we should accounts against where the page
really is, we already know where the task is.
So modify all three sites to always account; we did after all receive
the fault; and always account to where the page is after migration,
regardless of success.
They all still differ on when they clear the PTE/PMD; ideally that
would get sorted too.
Signed-off-by: Mel Gorman <mgorman at suse.de>
Reviewed-by: Rik van Riel <riel at redhat.com>
Cc: Andrea Arcangeli <aarcange at redhat.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz at infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-8-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo at kernel.org>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
mm/huge_memory.c | 23 ++++++++++++-----------
mm/memory.c | 53 +++++++++++++++++++++--------------------------------
2 files changed, 33 insertions(+), 43 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b698c7b..1390fdd 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1300,18 +1300,19 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
struct anon_vma *anon_vma = NULL;
struct page *page;
unsigned long haddr = addr & HPAGE_PMD_MASK;
+ int page_nid = -1, this_nid = numa_node_id();
int target_nid;
- int current_nid = -1;
- bool migrated, page_locked;
+ bool page_locked;
+ bool migrated = false;
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_same(pmd, *pmdp)))
goto out_unlock;
page = pmd_page(pmd);
- current_nid = page_to_nid(page);
+ page_nid = page_to_nid(page);
count_vm_numa_event(NUMA_HINT_FAULTS);
- if (current_nid == numa_node_id())
+ if (page_nid == this_nid)
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
/*
@@ -1354,13 +1355,12 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
spin_unlock(&mm->page_table_lock);
migrated = migrate_misplaced_transhuge_page(mm, vma,
pmdp, pmd, addr, page, target_nid);
- if (!migrated)
+ if (migrated)
+ page_nid = target_nid;
+ else
goto check_same;
- task_numa_fault(target_nid, HPAGE_PMD_NR, true);
- if (anon_vma)
- page_unlock_anon_vma_read(anon_vma);
- return 0;
+ goto out;
check_same:
spin_lock(&mm->page_table_lock);
@@ -1378,8 +1378,9 @@ out:
if (anon_vma)
page_unlock_anon_vma_read(anon_vma);
- if (current_nid != -1)
- task_numa_fault(current_nid, HPAGE_PMD_NR, false);
+ if (page_nid != -1)
+ task_numa_fault(page_nid, HPAGE_PMD_NR, migrated);
+
return 0;
}
diff --git a/mm/memory.c b/mm/memory.c
index 35b6109..5bcfbc1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3485,12 +3485,12 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
}
int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
- unsigned long addr, int current_nid)
+ unsigned long addr, int page_nid)
{
get_page(page);
count_vm_numa_event(NUMA_HINT_FAULTS);
- if (current_nid == numa_node_id())
+ if (page_nid == numa_node_id())
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
return mpol_misplaced(page, vma, addr);
@@ -3501,7 +3501,7 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
{
struct page *page = NULL;
spinlock_t *ptl;
- int current_nid = -1;
+ int page_nid = -1;
int target_nid;
bool migrated = false;
@@ -3531,15 +3531,10 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
return 0;
}
- current_nid = page_to_nid(page);
- target_nid = numa_migrate_prep(page, vma, addr, current_nid);
+ page_nid = page_to_nid(page);
+ target_nid = numa_migrate_prep(page, vma, addr, page_nid);
pte_unmap_unlock(ptep, ptl);
if (target_nid == -1) {
- /*
- * Account for the fault against the current node if it not
- * being replaced regardless of where the page is located.
- */
- current_nid = numa_node_id();
put_page(page);
goto out;
}
@@ -3547,11 +3542,11 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
/* Migrate to the requested node */
migrated = migrate_misplaced_page(page, target_nid);
if (migrated)
- current_nid = target_nid;
+ page_nid = target_nid;
out:
- if (current_nid != -1)
- task_numa_fault(current_nid, 1, migrated);
+ if (page_nid != -1)
+ task_numa_fault(page_nid, 1, migrated);
return 0;
}
@@ -3566,7 +3561,6 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long offset;
spinlock_t *ptl;
bool numa = false;
- int local_nid = numa_node_id();
spin_lock(&mm->page_table_lock);
pmd = *pmdp;
@@ -3589,9 +3583,10 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
for (addr = _addr + offset; addr < _addr + PMD_SIZE; pte++, addr += PAGE_SIZE) {
pte_t pteval = *pte;
struct page *page;
- int curr_nid = local_nid;
+ int page_nid = -1;
int target_nid;
- bool migrated;
+ bool migrated = false;
+
if (!pte_present(pteval))
continue;
if (!pte_numa(pteval))
@@ -3613,25 +3608,19 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (unlikely(page_mapcount(page) != 1))
continue;
- /*
- * Note that the NUMA fault is later accounted to either
- * the node that is currently running or where the page is
- * migrated to.
- */
- curr_nid = local_nid;
- target_nid = numa_migrate_prep(page, vma, addr,
- page_to_nid(page));
- if (target_nid == -1) {
+ page_nid = page_to_nid(page);
+ target_nid = numa_migrate_prep(page, vma, addr, page_nid);
+ pte_unmap_unlock(pte, ptl);
+ if (target_nid != -1) {
+ migrated = migrate_misplaced_page(page, target_nid);
+ if (migrated)
+ page_nid = target_nid;
+ } else {
put_page(page);
- continue;
}
- /* Migrate to the requested node */
- pte_unmap_unlock(pte, ptl);
- migrated = migrate_misplaced_page(page, target_nid);
- if (migrated)
- curr_nid = target_nid;
- task_numa_fault(curr_nid, 1, migrated);
+ if (page_nid != -1)
+ task_numa_fault(page_nid, 1, migrated);
pte = pte_offset_map_lock(mm, pmdp, addr, &ptl);
}
--
1.8.1.2
More information about the kernel-team
mailing list