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=-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=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 CE943C43461 for ; Wed, 5 May 2021 00:32:30 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 58CE4613D6 for ; Wed, 5 May 2021 00:32:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 58CE4613D6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5ADAF6B006E; Tue, 4 May 2021 20:32:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 545D36B0070; Tue, 4 May 2021 20:32:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 427B06B0070; Tue, 4 May 2021 20:32:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0041.hostedemail.com [216.40.44.41]) by kanga.kvack.org (Postfix) with ESMTP id 2120C6B006C for ; Tue, 4 May 2021 20:32:29 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D3843A760 for ; Wed, 5 May 2021 00:32:28 +0000 (UTC) X-FDA: 78105301176.20.BA3D895 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf17.hostedemail.com (Postfix) with ESMTP id AB44A40001FE for ; Wed, 5 May 2021 00:32:22 +0000 (UTC) IronPort-SDR: Me9fbKputU29/Kw1rxFgZfNapL25i+YdpYMV6O7Qy71xry4ida9CebpwUPIo3AqArWhE5sJEmh l8GyGF1jzcKg== X-IronPort-AV: E=McAfee;i="6200,9189,9974"; a="197724332" X-IronPort-AV: E=Sophos;i="5.82,273,1613462400"; d="scan'208";a="197724332" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2021 17:32:25 -0700 IronPort-SDR: Iqxtos5fBejOav42mmvTJRDDIz1U5Vp7QaFm+HjYB+C39Wrj+ro+IYxYBe5DN6g/vXjOtSpPYM b0fjED5YE9tg== X-IronPort-AV: E=Sophos;i="5.82,273,1613462400"; d="scan'208";a="429490755" Received: from rpedgeco-mobl3.amr.corp.intel.com (HELO localhost.intel.com) ([10.209.26.68]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 May 2021 17:32:24 -0700 From: Rick Edgecombe To: dave.hansen@intel.com, luto@kernel.org, peterz@infradead.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, linux-hardening@vger.kernel.org, kernel-hardening@lists.openwall.com Cc: ira.weiny@intel.com, rppt@kernel.org, dan.j.williams@intel.com, linux-kernel@vger.kernel.org, Rick Edgecombe Subject: [PATCH RFC 1/9] list: Support getting most recent element in list_lru Date: Tue, 4 May 2021 17:30:24 -0700 Message-Id: <20210505003032.489164-2-rick.p.edgecombe@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210505003032.489164-1-rick.p.edgecombe@intel.com> References: <20210505003032.489164-1-rick.p.edgecombe@intel.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: AB44A40001FE Authentication-Results: imf17.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf17.hostedemail.com: domain of rick.p.edgecombe@intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=rick.p.edgecombe@intel.com X-Rspamd-Server: rspam04 X-Stat-Signature: u6anago794aig8jqzowdxrqq5ah7nexr Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=mga14.intel.com; client-ip=192.55.52.115 X-HE-DKIM-Result: none/none X-HE-Tag: 1620174742-925543 Content-Transfer-Encoding: quoted-printable 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 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); =20 +/** + * list_lru_get_mru: gets and removes the tail from one of the node list= s + * @list_lru: the lru pointer + * @nid: the node id + * + * This function removes the most recently added item from one of the no= de + * id specified. This function should not be used if the list_lru is mem= cg + * 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 @l= ru * @lru: the lru pointer. diff --git a/mm/list_lru.c b/mm/list_lru.c index 6f067b6b935f..fd5b19dcfc72 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); =20 +struct list_head *list_lru_get_mru(struct list_lru *lru, int nid) +{ + struct list_lru_node *nlru =3D &lru->node[nid]; + struct list_lru_one *l =3D &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 =3D NULL; + } else { + /* Get tail */ + ret =3D 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); --=20 2.30.2