The patch titled
Subject: mempolicy: do not try to queue pages from !vma_migratable()
has been removed from the -mm tree. Its filename was
mempolicy-do-not-try-to-queue-pages-from-vma_migratable.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Subject: mempolicy: do not try to queue pages from !vma_migratable()
Maybe I miss some point, but I don't see a reason why we try to queue
pages from non migratable VMAs.
This testcase steps on VM_BUG_ON_PAGE() in isolate_lru_page():
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
#include <numaif.h>
#define SIZE 0x2000
int foo;
int main()
{
int fd;
char *p;
unsigned long mask = 2;
fd = open("/dev/sg0", O_RDWR);
p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
/* Faultin pages */
foo = p[0] + p[0x1000];
mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT);
return 0;
}
The only case when we can queue pages from such VMA is MPOL_MF_STRICT plus
MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU, but gfp
mask is not sutable for migaration (see mapping_gfp_mask() check in
vma_migratable()). That's looks like a bug to me.
Let's filter out non-migratable vma at start of queue_pages_test_walk()
and go to queue_pages_pte_range() only if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL
flag is set.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff -puN mm/mempolicy.c~mempolicy-do-not-try-to-queue-pages-from-vma_migratable mm/mempolicy.c
--- a/mm/mempolicy.c~mempolicy-do-not-try-to-queue-pages-from-vma_migratable
+++ a/mm/mempolicy.c
@@ -548,8 +548,7 @@ retry:
goto retry;
}
- if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
- migrate_page_add(page, qp->pagelist, flags);
+ migrate_page_add(page, qp->pagelist, flags);
}
pte_unmap_unlock(pte - 1, ptl);
cond_resched();
@@ -625,7 +624,7 @@ static int queue_pages_test_walk(unsigne
unsigned long endvma = vma->vm_end;
unsigned long flags = qp->flags;
- if (vma->vm_flags & VM_PFNMAP)
+ if (!vma_migratable(vma))
return 1;
if (endvma > end)
@@ -644,16 +643,13 @@ static int queue_pages_test_walk(unsigne
if (flags & MPOL_MF_LAZY) {
/* Similar to task_numa_work, skip inaccessible VMAs */
- if (vma_migratable(vma) &&
- vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))
+ if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))
change_prot_numa(vma, start, endvma);
return 1;
}
- if ((flags & MPOL_MF_STRICT) ||
- ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
- vma_migratable(vma)))
- /* queue pages from current vma */
+ /* queue pages from current vma */
+ if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
return 0;
return 1;
}
_
Patches currently in -mm which might be from kirill.shutemov@xxxxxxxxxxxxxxx are
mm-dax-check-for-pmd_none-after-split_huge_pmd.patch
ipc-shm-handle-removed-segments-gracefully-in-shm_mmap.patch
thp-cleanup-split_huge_page.patch
thp-vmstats-count-deferred-split-events.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix-2.patch
mm-make-swapin-readahead-to-improve-thp-collapse-rate-fix-3.patch
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