From nobody Sun Feb 8 11:22:01 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A07EC76195 for ; Thu, 23 Mar 2023 12:26:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231220AbjCWM0a (ORCPT ); Thu, 23 Mar 2023 08:26:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230293AbjCWM0X (ORCPT ); Thu, 23 Mar 2023 08:26:23 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C72F27D43 for ; Thu, 23 Mar 2023 05:26:06 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Pj4HL6Q7Bz17MjC; Thu, 23 Mar 2023 20:22:54 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Thu, 23 Mar 2023 20:26:02 +0800 From: Yicong Yang To: , , , , , CC: , , Subject: [PATCH] cacheinfo: Fix LLC is not exported through sysfs Date: Thu, 23 Mar 2023 20:25:28 +0800 Message-ID: <20230323122528.16691-1-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.50.163.32] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Yicong Yang After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI based arm64 server. This is because the LLC cacheinfo is partly reset when secondary CPUs boot up. On arm64 the primary cpu will allocate and setup cacheinfo: init_cpu_topology() for_each_possible_cpu() fetch_cache_info() // Allocate cacheinfo and init levels detect_cache_attributes() cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // not valid, setup LLC cache_setup_properties() // setup LLC On secondary CPU boot up: detect_cache_attributes() populate_cache_leaves() get_cache_type() // Get cache type from clidr_el1, // for LLC type=3DCACHE_TYPE_NOCACHE cache_shared_cpu_map_setup() if (!last_level_cache_is_valid()) // Valid and won't go to this branch, // leave LLC's type=3DCACHE_TYPE_NOCA= CHE The last_level_cache_is_valid() use cacheinfo->{attributes, fw_token} to test it's valid or not, but populate_cache_leaves() will only reset LLC's type, so we won't try to re-setup LLC's type and leave it CACHE_TYPE_NOCACHE and won't export it through sysfs. This patch tries to fix this by not re-populating the cache leaves if the LLC is valid. Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU") Signed-off-by: Yicong Yang --- drivers/base/cacheinfo.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index f6573c335f4c..d65f169d36dd 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -473,6 +473,13 @@ int detect_cache_attributes(unsigned int cpu) return ret; =20 populate_leaves: + /* + * If LLC is valid the cache leaves were already populated so just go to + * update the cpu map. + */ + if (last_level_cache_is_valid(cpu)) + goto update_cpu_map; + /* * populate_cache_leaves() may completely setup the cache leaves and * shared_cpu_map or it may leave it partially setup. @@ -481,6 +488,7 @@ int detect_cache_attributes(unsigned int cpu) if (ret) goto free_ci; =20 +update_cpu_map: /* * For systems using DT for cache hierarchy, fw_token * and shared_cpu_map will be set up here only if they are --=20 2.24.0