From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B1A8C432BE for ; Mon, 23 Aug 2021 13:25:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D6C4613CE for ; Mon, 23 Aug 2021 13:25:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237373AbhHWN0K (ORCPT ); Mon, 23 Aug 2021 09:26:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:43938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237256AbhHWN0H (ORCPT ); Mon, 23 Aug 2021 09:26:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id D9B9061373; Mon, 23 Aug 2021 13:25:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629725125; bh=43OttOoA+izE3bbLjhYbj+Uvn2nbLJSqbfY6UbauX60=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FwBAEvyYU68YR66QYkCvLp/UcpgFL3duRG70qZ2A4lA8BrU0x6jHAZYeGgp1amwqu afOnmIVmw98H4hHFdzx0IreEinrtA8UTYsAlnSQViHjCXz2yviZvTKEKJpFxuD8HkT DRO0N4Q6aJkHGldSsy95NrvKdouarsTMvULBQRvqt7tkskWClXqogS0ETI8k0v7fzB sEYDY1eBvfyo/fYeHuOmZU0DxvDFUmBojV6bgIMo5mrifSvG0eXqaOJ1uA1CPIOdSA q7JwncGNNyTNTOoV0OBGpIoVYmKUuP8wzh8hOe+DdeZ4fXgacQecZRDykl+utC4mov pERKRUDFUM6wg== From: Mike Rapoport To: linux-mm@kvack.org Cc: Andrew Morton , Andy Lutomirski , Dave Hansen , Ira Weiny , Kees Cook , Mike Rapoport , Mike Rapoport , Peter Zijlstra , Rick Edgecombe , Vlastimil Babka , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 1/4] list: Support getting most recent element in list_lru Date: Mon, 23 Aug 2021 16:25:10 +0300 Message-Id: <20210823132513.15836-2-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210823132513.15836-1-rppt@kernel.org> References: <20210823132513.15836-1-rppt@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rick Edgecombe In future patches, some functionality will use list_lru that also needs to keep track of the most recently used element on a node. Since this information is already contained within list_lru, add a function to get it so that an additional list is not needed in the caller. Do not support memcg aware list_lru's since it is not needed by the intended caller. Signed-off-by: Rick Edgecombe --- include/linux/list_lru.h | 13 +++++++++++++ mm/list_lru.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h index 1b5fceb565df..08e07c19fd13 100644 --- a/include/linux/list_lru.h +++ b/include/linux/list_lru.h @@ -103,6 +103,19 @@ 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_get_mru: gets and removes the tail from one of the node lists + * @list_lru: the lru pointer + * @nid: the node id + * + * This function removes the most recently added item from one of the node + * id specified. This function should not be used if the list_lru is memcg + * aware. + * + * Return value: The element removed + */ +struct list_head *list_lru_get_mru(struct list_lru *lru, int nid); + /** * list_lru_count_one: return the number of objects currently held by @lru * @lru: the lru pointer. diff --git a/mm/list_lru.c b/mm/list_lru.c index cd58790d0fb3..c1bec58168e1 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -156,6 +156,34 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item) } EXPORT_SYMBOL_GPL(list_lru_del); +struct list_head *list_lru_get_mru(struct list_lru *lru, int nid) +{ + struct list_lru_node *nlru = &lru->node[nid]; + struct list_lru_one *l = &nlru->lru; + struct list_head *ret; + + /* This function does not attempt to search through the memcg lists */ + if (list_lru_memcg_aware(lru)) { + WARN_ONCE(1, "list_lru: %s not supported on memcg aware list_lrus", __func__); + return NULL; + } + + spin_lock(&nlru->lock); + if (list_empty(&l->list)) { + ret = NULL; + } else { + /* Get tail */ + ret = l->list.prev; + list_del_init(ret); + + l->nr_items--; + nlru->nr_items--; + } + spin_unlock(&nlru->lock); + + return ret; +} + void list_lru_isolate(struct list_lru_one *list, struct list_head *item) { list_del_init(item); -- 2.28.0