Commit 9f40604c authored by Mel Gorman's avatar Mel Gorman

sched, numa, mm: Count WS scanning against present PTEs, not virtual memory ranges

By accounting against the present PTEs, scanning speed reflects the
actual present (mapped) memory.
Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
parent 6e5fb223
......@@ -827,8 +827,8 @@ void task_numa_work(struct callback_head *work)
struct task_struct *p = current;
struct mm_struct *mm = p->mm;
struct vm_area_struct *vma;
unsigned long offset, end;
long length;
unsigned long start, end;
long pages;
WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work));
......@@ -858,18 +858,20 @@ void task_numa_work(struct callback_head *work)
if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate)
return;
offset = mm->numa_scan_offset;
length = sysctl_numa_balancing_scan_size;
length <<= 20;
start = mm->numa_scan_offset;
pages = sysctl_numa_balancing_scan_size;
pages <<= 20 - PAGE_SHIFT; /* MB in pages */
if (!pages)
return;
down_read(&mm->mmap_sem);
vma = find_vma(mm, offset);
vma = find_vma(mm, start);
if (!vma) {
reset_ptenuma_scan(p);
offset = 0;
start = 0;
vma = mm->mmap;
}
for (; vma && length > 0; vma = vma->vm_next) {
for (; vma; vma = vma->vm_next) {
if (!vma_migratable(vma))
continue;
......@@ -877,15 +879,19 @@ void task_numa_work(struct callback_head *work)
if (((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < HPAGE_PMD_NR)
continue;
offset = max(offset, vma->vm_start);
end = min(ALIGN(offset + length, HPAGE_SIZE), vma->vm_end);
length -= end - offset;
change_prot_numa(vma, offset, end);
do {
start = max(start, vma->vm_start);
end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);
end = min(end, vma->vm_end);
pages -= change_prot_numa(vma, start, end);
offset = end;
start = end;
if (pages <= 0)
goto out;
} while (end != vma->vm_end);
}
out:
/*
* It is possible to reach the end of the VMA list but the last few VMAs are
* not guaranteed to the vma_migratable. If they are not, we would find the
......@@ -893,7 +899,7 @@ void task_numa_work(struct callback_head *work)
* so check it now.
*/
if (vma)
mm->numa_scan_offset = offset;
mm->numa_scan_offset = start;
else
reset_ptenuma_scan(p);
up_read(&mm->mmap_sem);
......
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