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[2620:137:e000::3:2]) by mx.google.com with ESMTPS id i27-20020a25b21b000000b00da043f5eef5si4601582ybj.535.2023.10.25.11.04.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Oct 2023 11:04:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by agentk.vger.email (Postfix) with ESMTP id B58018023A3C; Wed, 25 Oct 2023 11:04:37 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at agentk.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234496AbjJYSEF (ORCPT + 99 others); Wed, 25 Oct 2023 14:04:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234883AbjJYSEB (ORCPT ); Wed, 25 Oct 2023 14:04:01 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C8495A3 for ; Wed, 25 Oct 2023 11:03:58 -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 219BA1FB; Wed, 25 Oct 2023 11:04:40 -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 C1C7A3F738; Wed, 25 Oct 2023 11:03:55 -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, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com Subject: [PATCH v7 00/24] x86/resctrl: monitored closid+rmid together, separate arch/fs locking Date: Wed, 25 Oct 2023 18:03:21 +0000 Message-Id: <20231025180345.28061-1-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on agentk.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (agentk.vger.email [0.0.0.0]); Wed, 25 Oct 2023 11:04:37 -0700 (PDT) The only significant change in this series is to add cpus_read_lock() around the limbo and overflow handlers in the last patch. Other changes are a mix of comments and whitespace, or code marked __exit. Changes are noted in each patch, some patches even say 'No changes since v6'! ~ This series does two things, it changes resctrl to call resctrl_arch_rmid_read() in a way that works for MPAM, and it separates the locking so that the arch code and filesystem code don't have to share a mutex. I tried to split this as two series, but these touch similar call sites, so it would create more work. (What's MPAM? See the cover letter of the first series. [1]) On x86 the RMID is an independent number. MPAMs equivalent is PMG, but this isn't an independent number - it extends the PARTID (same as CLOSID) space with bits that aren't used to select the configuration. The monitors can then be told to match specific PMG values, allowing monitor-groups to be created. But, MPAM expects the monitors to always monitor by PARTID. The Cache-storage-utilisation counters can only work this way. (In the MPAM spec not setting the MATCH_PARTID bit is made CONSTRAINED UNPREDICTABLE - which is Arm's term to mean portable software can't rely on this) It gets worse, as some SoCs may have very few PMG bits. I've seen the datasheet for one that has a single bit of PMG space. To be usable, MPAM's counters always need the PARTID and the PMG. For resctrl, this means always making the CLOSID available when the RMID is used. To ensure RMID are always unique, this series combines the CLOSID and RMID into an index, and manages RMID based on that. For x86, the index and RMID would always be the same. Currently the architecture specific code in the cpuhp callbacks takes the rdtgroup_mutex. This means the filesystem code would have to export this lock, resulting in an ill-defined interface between the two, and the possibility of cross-architecture lock-ordering head aches. The second part of this series adds a domain_list_lock to protect writes to the domain list, and protects the domain list with RCU - or cpus_read_lock(). Use of RCU is to allow lockless readers of the domain list. To get MPAMs monitors working, its very likely they'll need to be plumbed up to perf. An uncore PMU driver would need to be a lockless reader of the domain list. This series is based on tip/master's commit 6b7b1e57a824, and can be retrieved from: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git mpam/monitors_and_locking/v7 Bugs welcome, Thanks, James [1] https://lore.kernel.org/lkml/20210728170637.25610-1-james.morse@arm.com/ [v1] https://lore.kernel.org/all/20221021131204.5581-1-james.morse@arm.com/ [v2] https://lore.kernel.org/lkml/20230113175459.14825-1-james.morse@arm.com/ [v3] https://lore.kernel.org/r/20230320172620.18254-1-james.morse@arm.com [v4] https://lore.kernel.org/r/20230525180209.19497-1-james.morse@arm.com [v5] https://lore.kernel.org/lkml/20230728164254.27562-1-james.morse@arm.com/ [v6] https://lore.kernel.org/all/20230914172138.11977-1-james.morse@arm.com/ James Morse (24): tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef x86/resctrl: kfree() rmid_ptrs from rdtgroup_exit() x86/resctrl: Create helper for RMID allocation and mondata dir creation x86/resctrl: Move rmid allocation out of mkdir_rdt_prepare() x86/resctrl: Track the closid with the rmid x86/resctrl: Access per-rmid structures by index x86/resctrl: Allow RMID allocation to be scoped by CLOSID x86/resctrl: Track the number of dirty RMID a CLOSID has x86/resctrl: Use __set_bit()/__clear_bit() instead of open coding x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid x86/resctrl: Move CLOSID/RMID matching and setting to use helpers x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow x86/resctrl: Queue mon_event_read() instead of sending an IPI x86/resctrl: Allow resctrl_arch_rmid_read() to sleep x86/resctrl: Allow arch to allocate memory needed in resctrl_arch_rmid_read() x86/resctrl: Make resctrl_mounted checks explicit x86/resctrl: Move alloc/mon static keys into helpers x86/resctrl: Make rdt_enable_key the arch's decision to switch x86/resctrl: Add helpers for system wide mon/alloc capable x86/resctrl: Add CPU online callback for resctrl work x86/resctrl: Allow overflow/limbo handlers to be scheduled on any-but cpu x86/resctrl: Add CPU offline callback for resctrl work x86/resctrl: Move domain helper migration into resctrl_offline_cpu() x86/resctrl: Separate arch and fs resctrl locks arch/x86/include/asm/resctrl.h | 90 +++++ arch/x86/kernel/cpu/resctrl/core.c | 94 ++--- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 48 ++- arch/x86/kernel/cpu/resctrl/internal.h | 67 +++- arch/x86/kernel/cpu/resctrl/monitor.c | 453 +++++++++++++++++----- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 15 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 349 ++++++++++++----- include/linux/resctrl.h | 48 ++- include/linux/tick.h | 9 +- 9 files changed, 903 insertions(+), 270 deletions(-) -- 2.39.2