Re: [PATCH 08/13] list: add a new LRU list type
From: Christoph Hellwig <hch@infradead.org>
Date: 2011-08-23 09:20:56
Also in:
linux-fsdevel, lkml
On Tue, Aug 23, 2011 at 06:56:21PM +1000, Dave Chinner wrote:
From: Dave Chinner <redacted> Several subsystems use the same construct for LRU lists - a list head, a spin lock and and item count. They also use exactly the same code for adding and removing items from the LRU. Create a generic type for these LRU lists. This is the beginning of generic, node aware LRUs for shrinkers to work with.
Why list_lru vs the more natural sounding lru_list?
quoted hunk ↗ jump to hunk
diff --git a/lib/Makefile b/lib/Makefile index d5d175c..a08212f 100644 --- a/lib/Makefile +++ b/lib/Makefile@@ -12,7 +12,8 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o prio_heap.o ratelimit.o show_mem.o \ - is_single_threaded.o plist.o decompress.o find_next_bit.o + is_single_threaded.o plist.o decompress.o find_next_bit.o \ + list_lru.o
Di we finally fix the issues with lib-y objects beeing discarded despite modules relying on the exports?
+int
+list_lru_add(
+ struct list_lru *lru,
+ struct list_head *item)
+{What about some kerneldoc comments for the helpers?
+ ret = isolate(item, &lru->lock, cb_arg);
+ switch (ret) {
+ case 0: /* item removed from list */
+ lru->nr_items--;
+ removed++;
+ break;
+ case 1: /* item referenced, give another pass */
+ list_move_tail(item, &lru->list);
+ break;
+ case 2: /* item cannot be locked, skip */
+ break;
+ case 3: /* item not freeable, lock dropped */
+ goto restart;I think the isolate callback returns shoud have symbolic names, i.e. and enum lru_isolate or similar.
+int
+list_lru_init(
+ struct list_lru *lru)
+{
+ spin_lock_init(&lru->lock);
+ INIT_LIST_HEAD(&lru->list);
+ lru->nr_items = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(list_lru_init);This one doesn't need a return value. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>