From nobody Mon Feb 9 23:44:58 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 71B89C001DF for ; Fri, 28 Jul 2023 16:44:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235272AbjG1Qoq (ORCPT ); Fri, 28 Jul 2023 12:44:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234089AbjG1Qnh (ORCPT ); Fri, 28 Jul 2023 12:43:37 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 37FB64208 for ; Fri, 28 Jul 2023 09:43:36 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 12542D75; Fri, 28 Jul 2023 09:44:19 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4624C3F67D; Fri, 28 Jul 2023 09:43:33 -0700 (PDT) From: James Morse To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , James Morse , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com Subject: [PATCH v5 06/24] x86/resctrl: Track the number of dirty RMID a CLOSID has Date: Fri, 28 Jul 2023 16:42:36 +0000 Message-Id: <20230728164254.27562-7-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230728164254.27562-1-james.morse@arm.com> References: <20230728164254.27562-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" MPAM's PMG bits extend its PARTID space, meaning the same PMG value can be used for different control groups. This means once a CLOSID is allocated, all its monitoring ids may still be dirty, and held in limbo. Keep track of the number of RMID held in limbo each CLOSID has. This will allow a future helper to find the 'cleanest' CLOSID when allocating. The array is only needed when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. This will never be the case on x86. Signed-off-by: James Morse --- Changes since v4: * Moved closid_num_dirty_rmid[] update under entry->busy check * Take the mutex in dom_data_init() as the caller doesn't. --- arch/x86/kernel/cpu/resctrl/monitor.c | 49 +++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/re= sctrl/monitor.c index de91ca781d9f..44addc0126fc 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -43,6 +43,13 @@ struct rmid_entry { */ static LIST_HEAD(rmid_free_lru); =20 +/** + * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has. + * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined. + * Indexed by CLOSID. Protected by rdtgroup_mutex. + */ +static int *closid_num_dirty_rmid; + /** * @rmid_limbo_count count of currently unused but (potentially) * dirty RMIDs. @@ -285,6 +292,17 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, str= uct rdt_domain *d, return 0; } =20 +static void limbo_release_entry(struct rmid_entry *entry) +{ + lockdep_assert_held(&rdtgroup_mutex); + + rmid_limbo_count--; + list_add_tail(&entry->list, &rmid_free_lru); + + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]--; +} + /* * Check the RMIDs that are marked as busy for this domain. If the * reported LLC occupancy is below the threshold clear the busy bit and @@ -321,10 +339,8 @@ void __check_limbo(struct rdt_domain *d, bool force_fr= ee) =20 if (force_free || !rmid_dirty) { clear_bit(idx, d->rmid_busy_llc); - if (!--entry->busy) { - rmid_limbo_count--; - list_add_tail(&entry->list, &rmid_free_lru); - } + if (!--entry->busy) + limbo_release_entry(entry); } cur_idx =3D idx + 1; } @@ -391,6 +407,8 @@ static void add_rmid_to_limbo(struct rmid_entry *entry) u64 val =3D 0; u32 idx; =20 + lockdep_assert_held(&rdtgroup_mutex); + idx =3D resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid); =20 entry->busy =3D 0; @@ -416,9 +434,11 @@ static void add_rmid_to_limbo(struct rmid_entry *entry) } put_cpu(); =20 - if (entry->busy) + if (entry->busy) { rmid_limbo_count++; - else + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) + closid_num_dirty_rmid[entry->closid]++; + } else list_add_tail(&entry->list, &rmid_free_lru); } =20 @@ -782,13 +802,28 @@ void mbm_setup_overflow_handler(struct rdt_domain *do= m, unsigned long delay_ms) static int dom_data_init(struct rdt_resource *r) { u32 idx_limit =3D resctrl_arch_system_num_rmid_idx(); + u32 num_closid =3D resctrl_arch_get_num_closid(r); struct rmid_entry *entry =3D NULL; u32 idx; int i; =20 + if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) { + int *tmp; + + tmp =3D kcalloc(num_closid, sizeof(int), GFP_KERNEL); + if (!tmp) + return -ENOMEM; + + mutex_lock(&rdtgroup_mutex); + closid_num_dirty_rmid =3D tmp; + mutex_unlock(&rdtgroup_mutex); + } + rmid_ptrs =3D kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL); - if (!rmid_ptrs) + if (!rmid_ptrs) { + kfree(closid_num_dirty_rmid); return -ENOMEM; + } =20 for (i =3D 0; i < idx_limit; i++) { entry =3D &rmid_ptrs[i]; --=20 2.39.2