Return-Path: Received: from mail-yk0-f169.google.com ([209.85.160.169]:35732 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751741AbbHTLRa (ORCPT ); Thu, 20 Aug 2015 07:17:30 -0400 Received: by ykbi184 with SMTP id i184so33651890ykb.2 for ; Thu, 20 Aug 2015 04:17:30 -0700 (PDT) From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org, hch@lst.de, kinglongmee@gmail.com, Andrew Morton , Vladimir Davydov , linux-mm@kvack.org Subject: [PATCH v3 03/20] list_lru: add list_lru_rotate Date: Thu, 20 Aug 2015 07:17:03 -0400 Message-Id: <1440069440-27454-4-git-send-email-jeff.layton@primarydata.com> In-Reply-To: <1440069440-27454-1-git-send-email-jeff.layton@primarydata.com> References: <1440069440-27454-1-git-send-email-jeff.layton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Add a function that can move an entry to the MRU end of the list. Cc: Andrew Morton Cc: Vladimir Davydov Cc: linux-mm@kvack.org Signed-off-by: Jeff Layton --- include/linux/list_lru.h | 13 +++++++++++++ mm/list_lru.c | 15 +++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h index 2a6b9947aaa3..4534b1b34d2d 100644 --- a/include/linux/list_lru.h +++ b/include/linux/list_lru.h @@ -96,6 +96,19 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item); bool list_lru_del(struct list_lru *lru, struct list_head *item); /** + * list_lru_rotate: rotate an element to the end of an lru list + * @list_lru: the lru pointer + * @item: the item to be rotated + * + * This function moves an entry to the end of an LRU list. Should be used when + * an entry that is on the LRU is used, and should be moved to the MRU end of + * the list. If the item is not on a list, then this function has no effect. + * The comments about an element already pertaining to a list are also valid + * for list_lru_rotate. + */ +void list_lru_rotate(struct list_lru *lru, struct list_head *item); + +/** * list_lru_count_one: return the number of objects currently held by @lru * @lru: the lru pointer. * @nid: the node id to count from. diff --git a/mm/list_lru.c b/mm/list_lru.c index e1da19fac1b3..66718c2a9a7b 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -130,6 +130,21 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item) } EXPORT_SYMBOL_GPL(list_lru_del); +void list_lru_rotate(struct list_lru *lru, struct list_head *item) +{ + int nid = page_to_nid(virt_to_page(item)); + struct list_lru_node *nlru = &lru->node[nid]; + struct list_lru_one *l; + + spin_lock(&nlru->lock); + if (!list_empty(item)) { + l = list_lru_from_kmem(nlru, item); + list_move_tail(item, &l->list); + } + spin_unlock(&nlru->lock); +} +EXPORT_SYMBOL_GPL(list_lru_rotate); + void list_lru_isolate(struct list_lru_one *list, struct list_head *item) { list_del_init(item); -- 2.4.3