s390/mm: disable KSM for storage key enabled pages

When storage keys are enabled unmerge already merged pages and prevent
new pages from being merged.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Dominik Dingel
2014-10-23 12:09:17 +02:00
committed by Martin Schwidefsky
parent 2faee8ff9d
commit 3ac8e38015
3 changed files with 28 additions and 7 deletions

View File

@@ -18,6 +18,8 @@
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/swapops.h>
#include <linux/ksm.h>
#include <linux/mman.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -1275,22 +1277,34 @@ static int __s390_enable_skey(pte_t *pte, unsigned long addr,
return 0;
}
void s390_enable_skey(void)
int s390_enable_skey(void)
{
struct mm_walk walk = { .pte_entry = __s390_enable_skey };
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
int rc = 0;
down_write(&mm->mmap_sem);
if (mm_use_skey(mm))
goto out_up;
mm->context.use_skey = 1;
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
MADV_UNMERGEABLE, &vma->vm_flags)) {
mm->context.use_skey = 0;
rc = -ENOMEM;
goto out_up;
}
}
mm->def_flags &= ~VM_MERGEABLE;
walk.mm = mm;
walk_page_range(0, TASK_SIZE, &walk);
out_up:
up_write(&mm->mmap_sem);
return rc;
}
EXPORT_SYMBOL_GPL(s390_enable_skey);