From patchwork Mon Aug 30 23:59:09 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: 12466131 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=-16.8 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=unavailable 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 EF9F0C19F38 for ; Tue, 31 Aug 2021 00:00:02 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 79A5D60E98 for ; Tue, 31 Aug 2021 00:00:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 79A5D60E98 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id ABFAD900002; Mon, 30 Aug 2021 20:00:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A44ED6B0072; Mon, 30 Aug 2021 20:00:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9350E900002; Mon, 30 Aug 2021 20:00:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id 849A66B0071 for ; Mon, 30 Aug 2021 20:00:00 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 34F41181AEF32 for ; Tue, 31 Aug 2021 00:00:00 +0000 (UTC) X-FDA: 78533417760.02.B8809C2 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by imf25.hostedemail.com (Postfix) with ESMTP id A1BA8B000182 for ; Mon, 30 Aug 2021 23:59:59 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10092"; a="205504310" X-IronPort-AV: E=Sophos;i="5.84,364,1620716400"; d="scan'208";a="205504310" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2021 16:59:57 -0700 X-IronPort-AV: E=Sophos;i="5.84,364,1620716400"; d="scan'208";a="530712796" Received: from ajinkyak-mobl2.amr.corp.intel.com (HELO rpedgeco-desk.amr.corp.intel.com) ([10.212.240.95]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2021 16:59:57 -0700 From: Rick Edgecombe To: dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org, x86@kernel.org, akpm@linux-foundation.org, keescook@chromium.org, shakeelb@google.com, vbabka@suse.cz, rppt@kernel.org Cc: Rick Edgecombe , linux-mm@kvack.org, linux-hardening@vger.kernel.org, kernel-hardening@lists.openwall.com, ira.weiny@intel.com, dan.j.williams@intel.com, linux-kernel@vger.kernel.org Subject: [RFC PATCH v2 01/19] list: Support getting most recent element in list_lru Date: Mon, 30 Aug 2021 16:59:09 -0700 Message-Id: <20210830235927.6443-2-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210830235927.6443-1-rick.p.edgecombe@intel.com> References: <20210830235927.6443-1-rick.p.edgecombe@intel.com> Authentication-Results: imf25.hostedemail.com; dkim=none; spf=none (imf25.hostedemail.com: domain of rick.p.edgecombe@intel.com has no SPF policy when checking 134.134.136.126) smtp.mailfrom=rick.p.edgecombe@intel.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none) X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: A1BA8B000182 X-Stat-Signature: wtqzp7g9jwj3453zh9bfac7rshr1nxrw X-HE-Tag: 1630367999-735676 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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);