diff options
Diffstat (limited to 'kernel/sys.c')
| -rw-r--r-- | kernel/sys.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index 26c1399e0654..72cdb16e2636 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -15,6 +15,7 @@ #include <linux/highuid.h> #include <linux/fs.h> #include <linux/kmod.h> +#include <linux/ksm.h> #include <linux/perf_event.h> #include <linux/resource.h> #include <linux/kernel.h> @@ -2687,6 +2688,32 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_VMA: error = prctl_set_vma(arg2, arg3, arg4, arg5); break; +#ifdef CONFIG_KSM + case PR_SET_MEMORY_MERGE: + if (arg3 || arg4 || arg5) + return -EINVAL; + if (mmap_write_lock_killable(me->mm)) + return -EINTR; + + if (arg2) { + error = ksm_enable_merge_any(me->mm); + } else { + /* + * TODO: we might want disable KSM on all VMAs and + * trigger unsharing to completely disable KSM. + */ + clear_bit(MMF_VM_MERGE_ANY, &me->mm->flags); + error = 0; + } + mmap_write_unlock(me->mm); + break; + case PR_GET_MEMORY_MERGE: + if (arg2 || arg3 || arg4 || arg5) + return -EINVAL; + + error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); + break; +#endif default: error = -EINVAL; break; |