-void cfs_waitq_init(cfs_waitq_t *waitq);
-void cfs_waitlink_init(cfs_waitlink_t *link);
-void cfs_waitq_add(cfs_waitq_t *waitq, cfs_waitlink_t *link);
-void cfs_waitq_add_exclusive(cfs_waitq_t *waitq,
- cfs_waitlink_t *link);
-void cfs_waitq_del(cfs_waitq_t *waitq, cfs_waitlink_t *link);
-int cfs_waitq_active(cfs_waitq_t *waitq);
-void cfs_waitq_signal(cfs_waitq_t *waitq);
-void cfs_waitq_signal_nr(cfs_waitq_t *waitq, int nr);
-void cfs_waitq_broadcast(cfs_waitq_t *waitq);
-void cfs_waitq_wait(cfs_waitlink_t *link, cfs_task_state_t state);
-int64_t cfs_waitq_timedwait(cfs_waitlink_t *link, cfs_task_state_t state,
- int64_t timeout);
+#if BITS_PER_LONG == 32
+/* limit to lowmem on 32-bit systems */
+# define NUM_CACHEPAGES \
+ min(cfs_totalram_pages(), 1UL << (30 - PAGE_SHIFT) * 3 / 4)
+#else
+# define NUM_CACHEPAGES cfs_totalram_pages()
+#endif