The patch titled
Subject: mm: merging memory blocks resets mempolicy
has been added to the -mm tree. Its filename is
mm-merging-memory-blocks-resets-mempolicy.patch
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------------------------------------------------------
From: "Hampson, Steven T" <steven.t.hampson@xxxxxxxxx>
Subject: mm: merging memory blocks resets mempolicy
Using mbind to change the mempolicy to MPOL_BIND on several adjacent
mmapped blocks may result in a reset of the mempolicy to MPOL_DEFAULT in
vma_adjust.
Test code. Correct result is three lines containing "OK".
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <numaif.h>
#include <errno.h>
/* gcc mbind_test.c -lnuma -o mbind_test -Wall */
#define MAXNODE 4096
void allocate()
{
int ret;
int len;
int policy = -1;
unsigned char *p;
unsigned long mask[MAXNODE] = { 0 };
unsigned long retmask[MAXNODE] = { 0 };
len = getpagesize() * 0x2fc00;
p = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS,
-1, 0);
if (p == MAP_FAILED)
printf("mbind err: %d\n", errno);
mask[0] = 1;
ret = mbind(p, len, MPOL_BIND, mask, MAXNODE, 0);
if (ret < 0)
printf("mbind err: %d %d\n", ret, errno);
ret = get_mempolicy(&policy, retmask, MAXNODE, p, MPOL_F_ADDR);
if (ret < 0)
printf("get_mempolicy err: %d %d\n", ret, errno);
if (policy == MPOL_BIND)
printf("OK\n");
else
printf("ERROR: policy is %d\n", policy);
}
int main()
{
allocate();
allocate();
allocate();
return 0;
}
Signed-off-by: Steven T Hampson <steven.t.hampson@xxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/mmap.c~mm-merging-memory-blocks-resets-mempolicy mm/mmap.c
--- a/mm/mmap.c~mm-merging-memory-blocks-resets-mempolicy
+++ a/mm/mmap.c
@@ -829,7 +829,7 @@ again: remove_next = 1 + (end > next->
if (next->anon_vma)
anon_vma_merge(vma, next);
mm->map_count--;
- mpol_put(vma_policy(next));
+ vma_set_policy(vma, vma_policy(next));
kmem_cache_free(vm_area_cachep, next);
/*
* In mprotect's case 6 (see comments on vma_merge),
_
Patches currently in -mm which might be from steven.t.hampson@xxxxxxxxx are
mm-merging-memory-blocks-resets-mempolicy.patch
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