mm: numa: Do not group on RO pages

And here's a little something to make sure not the whole world ends up
in a single group.

As while we don't migrate shared executable pages, we do scan/fault on
them. And since everybody links to libc, everybody ends up in the same
group.

Suggested-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1381141781-10992-47-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2013-10-07 11:29:24 +01:00 committed by Ingo Molnar
parent 7851a45cd3
commit 6688cc0547
4 changed files with 47 additions and 10 deletions

View File

@ -1450,13 +1450,16 @@ struct task_struct {
/* Future-safe accessor for struct task_struct's cpus_allowed. */
#define tsk_cpus_allowed(tsk) (&(tsk)->cpus_allowed)
#define TNF_MIGRATED 0x01
#define TNF_NO_GROUP 0x02
#ifdef CONFIG_NUMA_BALANCING
extern void task_numa_fault(int last_node, int node, int pages, bool migrated);
extern void task_numa_fault(int last_node, int node, int pages, int flags);
extern pid_t task_numa_group_id(struct task_struct *p);
extern void set_numabalancing_state(bool enabled);
#else
static inline void task_numa_fault(int last_node, int node, int pages,
bool migrated)
int flags)
{
}
static inline pid_t task_numa_group_id(struct task_struct *p)

View File

@ -1361,9 +1361,10 @@ void task_numa_free(struct task_struct *p)
/*
* Got a PROT_NONE fault for a page on @node.
*/
void task_numa_fault(int last_cpupid, int node, int pages, bool migrated)
void task_numa_fault(int last_cpupid, int node, int pages, int flags)
{
struct task_struct *p = current;
bool migrated = flags & TNF_MIGRATED;
int priv;
if (!numabalancing_enabled)
@ -1394,7 +1395,7 @@ void task_numa_fault(int last_cpupid, int node, int pages, bool migrated)
priv = 1;
} else {
priv = cpupid_match_pid(p, last_cpupid);
if (!priv)
if (!priv && !(flags & TNF_NO_GROUP))
task_numa_group(p, last_cpupid);
}

View File

@ -1285,6 +1285,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
int target_nid, last_cpupid = -1;
bool page_locked;
bool migrated = false;
int flags = 0;
spin_lock(&mm->page_table_lock);
if (unlikely(!pmd_same(pmd, *pmdp)))
@ -1298,6 +1299,14 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (page_nid == this_nid)
count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL);
/*
* Avoid grouping on DSO/COW pages in specific and RO pages
* in general, RO pages shouldn't hurt as much anyway since
* they can be in shared cache state.
*/
if (!pmd_write(pmd))
flags |= TNF_NO_GROUP;
/*
* Acquire the page lock to serialise THP migrations but avoid dropping
* page_table_lock if at all possible
@ -1343,8 +1352,10 @@ 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) {
flags |= TNF_MIGRATED;
page_nid = target_nid;
}
goto out;
clear_pmdnuma:
@ -1362,7 +1373,7 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
page_unlock_anon_vma_read(anon_vma);
if (page_nid != -1)
task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR, migrated);
task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR, flags);
return 0;
}

View File

@ -3547,6 +3547,7 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
int last_cpupid;
int target_nid;
bool migrated = false;
int flags = 0;
/*
* The "pte" at this point cannot be used safely without
@ -3575,6 +3576,14 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
}
BUG_ON(is_zero_pfn(page_to_pfn(page)));
/*
* Avoid grouping on DSO/COW pages in specific and RO pages
* in general, RO pages shouldn't hurt as much anyway since
* they can be in shared cache state.
*/
if (!pte_write(pte))
flags |= TNF_NO_GROUP;
last_cpupid = page_cpupid_last(page);
page_nid = page_to_nid(page);
target_nid = numa_migrate_prep(page, vma, addr, page_nid);
@ -3586,12 +3595,14 @@ int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
/* Migrate to the requested node */
migrated = migrate_misplaced_page(page, vma, target_nid);
if (migrated)
if (migrated) {
page_nid = target_nid;
flags |= TNF_MIGRATED;
}
out:
if (page_nid != -1)
task_numa_fault(last_cpupid, page_nid, 1, migrated);
task_numa_fault(last_cpupid, page_nid, 1, flags);
return 0;
}
@ -3632,6 +3643,7 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
int page_nid = -1;
int target_nid;
bool migrated = false;
int flags = 0;
if (!pte_present(pteval))
continue;
@ -3651,20 +3663,30 @@ static int do_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
if (unlikely(!page))
continue;
/*
* Avoid grouping on DSO/COW pages in specific and RO pages
* in general, RO pages shouldn't hurt as much anyway since
* they can be in shared cache state.
*/
if (!pte_write(pteval))
flags |= TNF_NO_GROUP;
last_cpupid = page_cpupid_last(page);
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, vma, target_nid);
if (migrated)
if (migrated) {
page_nid = target_nid;
flags |= TNF_MIGRATED;
}
} else {
put_page(page);
}
if (page_nid != -1)
task_numa_fault(last_cpupid, page_nid, 1, migrated);
task_numa_fault(last_cpupid, page_nid, 1, flags);
pte = pte_offset_map_lock(mm, pmdp, addr, &ptl);
}