From patchwork Mon Apr 5 20:37:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Edgecombe, Rick P" X-Patchwork-Id: 12183567 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 28BD7C43470 for ; Mon, 5 Apr 2021 20:41:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CFC4E613D9 for ; Mon, 5 Apr 2021 20:41:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240998AbhDEUlu (ORCPT ); Mon, 5 Apr 2021 16:41:50 -0400 Received: from mga02.intel.com ([134.134.136.20]:54260 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240981AbhDEUls (ORCPT ); Mon, 5 Apr 2021 16:41:48 -0400 IronPort-SDR: AFWMUZesQoSR1DfLA0fQKpIspA3/d803N5UdFWezrOb2DNNeNFtNBBg/A2Vn7qJZSfADol6QWM g8TzINH5lVrw== X-IronPort-AV: E=McAfee;i="6000,8403,9945"; a="180051523" X-IronPort-AV: E=Sophos;i="5.81,307,1610438400"; d="scan'208";a="180051523" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Apr 2021 13:41:32 -0700 IronPort-SDR: 7hHX1k0TTTvyZ4h8v4pVehE9bJvBiBYeYp/nm8oyolTxqnhRDfifj408AeFJeZmPojn84F2N+v tGkGPIYMXECg== X-IronPort-AV: E=Sophos;i="5.81,307,1610438400"; d="scan'208";a="418078027" Received: from rpedgeco-mobl3.amr.corp.intel.com (HELO localhost.intel.com) ([10.212.230.218]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Apr 2021 13:41:32 -0700 From: Rick Edgecombe To: akpm@linux-foundation.org, linux-mm@kvack.org, bpf@vger.kernel.org, dave.hansen@linux.intel.com, peterz@infradead.org, luto@kernel.org, jeyu@kernel.org Cc: linux-kernel@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, hch@infradead.org, x86@kernel.org, Rick Edgecombe Subject: [RFC 1/3] list: Support getting most recent element in list_lru Date: Mon, 5 Apr 2021 13:37:09 -0700 Message-Id: <20210405203711.1095940-2-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210405203711.1095940-1-rick.p.edgecombe@intel.com> References: <20210405203711.1095940-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-State: RFC 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 9dcaa3e582c9..4bde44a5024b 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 fe230081690b..a18d9ed8abd5 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);