{
if (capable(CAP_IPC_LOCK))
return 1;
- if (current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
+ if (rlimit(RLIMIT_MEMLOCK) != 0)
return 1;
return 0;
}
}
}
-/*
- * called from munlock()/munmap() path with page supposedly on the LRU.
+/**
+ * munlock_vma_page - munlock a vma page
+ * @page - page to be unlocked
*
- * Note: unlike mlock_vma_page(), we can't just clear the PageMlocked
- * [in try_to_munlock()] and then attempt to isolate the page. We must
- * isolate the page to keep others from messing with its unevictable
- * and mlocked state while trying to munlock. However, we pre-clear the
- * mlocked state anyway as we might lose the isolation race and we might
- * not get another chance to clear PageMlocked. If we successfully
- * isolate the page and try_to_munlock() detects other VM_LOCKED vmas
- * mapping the page, it will restore the PageMlocked state, unless the page
- * is mapped in a non-linear vma. So, we go ahead and ClearPageMlocked(),
- * perhaps redundantly.
- * If we lose the isolation race, and the page is mapped by other VM_LOCKED
- * vmas, we'll detect this in vmscan--via try_to_munlock() or try_to_unmap()
- * either of which will restore the PageMlocked state by calling
- * mlock_vma_page() above, if it can grab the vma's mmap sem.
+ * called from munlock()/munmap() path with page supposedly on the LRU.
+ * When we munlock a page, because the vma where we found the page is being
+ * munlock()ed or munmap()ed, we want to check whether other vmas hold the
+ * page locked so that we can leave it on the unevictable lru list and not
+ * bother vmscan with it. However, to walk the page's rmap list in
+ * try_to_munlock() we must isolate the page from the LRU. If some other
+ * task has removed the page from the LRU, we won't be able to do that.
+ * So we clear the PageMlocked as we might not get another chance. If we
+ * can't isolate the page, we leave it for putback_lru_page() and vmscan
+ * [page_referenced()/try_to_unmap()] to deal with.
*/
void munlock_vma_page(struct page *page)
{
putback_lru_page(page);
} else {
/*
- * We lost the race. let try_to_unmap() deal
- * with it. At least we get the page state and
- * mlock stats right. However, page is still on
- * the noreclaim list. We'll fix that up when
- * the page is eventually freed or we scan the
- * noreclaim list.
+ * Some other task has removed the page from the LRU.
+ * putback_lru_page() will take care of removing the
+ * page from the unevictable list, if necessary.
+ * vmscan [page_referenced()] will move the page back
+ * to the unevictable list if some other vma has it
+ * mlocked.
*/
if (PageUnevictable(page))
count_vm_event(UNEVICTABLE_PGSTRANDED);
locked = len >> PAGE_SHIFT;
locked += current->mm->locked_vm;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
/* check against resource limits */
down_write(¤t->mm->mmap_sem);
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
ret = -ENOMEM;
int allowed = 0;
locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
if (lock_limit == RLIM_INFINITY)
allowed = 1;
lock_limit >>= PAGE_SHIFT;
spin_unlock(&shmlock_user_lock);
free_uid(user);
}
-
-int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
- size_t size)
-{
- unsigned long lim, vm, pgsz;
- int error = -ENOMEM;
-
- pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
-
- down_write(&mm->mmap_sem);
-
- lim = rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
- vm = mm->total_vm + pgsz;
- if (lim < vm)
- goto out;
-
- lim = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
- vm = mm->locked_vm + pgsz;
- if (lim < vm)
- goto out;
-
- mm->total_vm += pgsz;
- mm->locked_vm += pgsz;
-
- error = 0;
- out:
- up_write(&mm->mmap_sem);
- return error;
-}
-
-void refund_locked_memory(struct mm_struct *mm, size_t size)
-{
- unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
-
- down_write(&mm->mmap_sem);
-
- mm->total_vm -= pgsz;
- mm->locked_vm -= pgsz;
-
- up_write(&mm->mmap_sem);
-}