#include <linux/sysctl.h>
#include <linux/oom.h>
#include <linux/prefetch.h>
+#include <linux/debugfs.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
return zone_page_state(lruvec_zone(lruvec), NR_LRU_BASE + lru);
}
+struct dentry *debug_file;
+
+static int debug_shrinker_show(struct seq_file *s, void *unused)
+{
+ struct shrinker *shrinker;
+ struct shrink_control sc;
+
+ sc.gfp_mask = -1;
+ sc.nr_to_scan = 0;
+
+ down_read(&shrinker_rwsem);
+ list_for_each_entry(shrinker, &shrinker_list, list) {
+ int num_objs;
+
+ num_objs = shrinker->shrink(shrinker, &sc);
+ seq_printf(s, "%pf %d\n", shrinker->shrink, num_objs);
+ }
+ up_read(&shrinker_rwsem);
+ return 0;
+}
+
+static int debug_shrinker_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, debug_shrinker_show, inode->i_private);
+}
+
+static const struct file_operations debug_shrinker_fops = {
+ .open = debug_shrinker_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
/*
* Add a shrinker callback to be called from the vm
*/
}
EXPORT_SYMBOL(register_shrinker);
+static int __init add_shrinker_debug(void)
+{
+ debugfs_create_file("shrinker", 0644, NULL, NULL,
+ &debug_shrinker_fops);
+ return 0;
+}
+
+late_initcall(add_shrinker_debug);
+
/*
* Remove one
*/
return false;
/*
- * There is a potential race between when kswapd checks its watermarks
- * and a process gets throttled. There is also a potential race if
- * processes get throttled, kswapd wakes, a large process exits therby
- * balancing the zones that causes kswapd to miss a wakeup. If kswapd
- * is going to sleep, no process should be sleeping on pfmemalloc_wait
- * so wake them now if necessary. If necessary, processes will wake
- * kswapd and get throttled again
+ * The throttled processes are normally woken up in balance_pgdat() as
+ * soon as pfmemalloc_watermark_ok() is true. But there is a potential
+ * race between when kswapd checks the watermarks and a process gets
+ * throttled. There is also a potential race if processes get
+ * throttled, kswapd wakes, a large process exits thereby balancing the
+ * zones, which causes kswapd to exit balance_pgdat() before reaching
+ * the wake up checks. If kswapd is going to sleep, no process should
+ * be sleeping on pfmemalloc_wait, so wake them now if necessary. If
+ * the wake up is premature, processes will wake kswapd and get
+ * throttled again. The difference from wake ups in balance_pgdat() is
+ * that here we are under prepare_to_wait().
*/
- if (waitqueue_active(&pgdat->pfmemalloc_wait)) {
- wake_up(&pgdat->pfmemalloc_wait);
- return false;
- }
+ if (waitqueue_active(&pgdat->pfmemalloc_wait))
+ wake_up_all(&pgdat->pfmemalloc_wait);
return pgdat_balanced(pgdat, order, classzone_idx);
}