From nobody Sat Dec 27 20:55:29 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E1A0341858 for ; Fri, 15 Dec 2023 17:45:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 AD30015DB; Fri, 15 Dec 2023 09:45:57 -0800 (PST) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BDE963F5A1; Fri, 15 Dec 2023 09:45:09 -0800 (PST) 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, Babu Moger Subject: [PATCH v8 23/24] x86/resctrl: Move domain helper migration into resctrl_offline_cpu() Date: Fri, 15 Dec 2023 17:43:42 +0000 Message-Id: <20231215174343.13872-24-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20231215174343.13872-1-james.morse@arm.com> References: <20231215174343.13872-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When a CPU is taken offline the resctrl filesystem code needs to check if it was the CPU nominated to perform the periodic overflow and limbo work. If so, another CPU needs to be chosen to do this work. This is currently done in core.c, mixed in with the code that removes the CPU from the domain's mask, and potentially free()s the domain. Move the migration of the overflow and limbo helpers into the filesystem code, into resctrl_offline_cpu(). As resctrl_offline_cpu() runs before the architecture code has removed the CPU from the domain mask, the callers need to be told which CPU is being removed, to avoid picking it as the new CPU. This uses the exclude_cpu feature previously added. Signed-off-by: James Morse Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Babu Moger Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: Babu Moger --- Changes since v5: * Changed fir tree order of variables. * Added mon-capable check for cpu offline. --- arch/x86/kernel/cpu/resctrl/core.c | 16 ---------------- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 18 ++++++++++++++++++ 2 files changed, 18 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resct= rl/core.c index 65540acd59de..c943cb78b2a1 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -582,22 +582,6 @@ static void domain_remove_cpu(int cpu, struct rdt_reso= urce *r) =20 return; } - - if (r =3D=3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl) { - if (is_mbm_enabled() && cpu =3D=3D d->mbm_work_cpu) { - cancel_delayed_work(&d->mbm_over); - /* - * temporary: exclude_cpu=3D-1 as this CPU has already - * been removed by cpumask_clear_cpu()d - */ - mbm_setup_overflow_handler(d, 0, RESCTRL_PICK_ANY_CPU); - } - if (is_llc_occupancy_enabled() && cpu =3D=3D d->cqm_work_cpu && - has_busy_rmid(d)) { - cancel_delayed_work(&d->cqm_limbo); - cqm_setup_limbo_handler(d, 0, RESCTRL_PICK_ANY_CPU); - } - } } =20 static void clear_closid_rmid(int cpu) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 958f73974860..f007c488fa31 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -4034,7 +4034,9 @@ static void clear_childcpus(struct rdtgroup *r, unsig= ned int cpu) =20 void resctrl_offline_cpu(unsigned int cpu) { + struct rdt_resource *l3 =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; struct rdtgroup *rdtgrp; + struct rdt_domain *d; =20 lockdep_assert_held(&rdtgroup_mutex); =20 @@ -4044,6 +4046,22 @@ void resctrl_offline_cpu(unsigned int cpu) break; } } + + if (!l3->mon_capable) + return; + + d =3D get_domain_from_cpu(cpu, l3); + if (d) { + if (is_mbm_enabled() && cpu =3D=3D d->mbm_work_cpu) { + cancel_delayed_work(&d->mbm_over); + mbm_setup_overflow_handler(d, 0, cpu); + } + if (is_llc_occupancy_enabled() && cpu =3D=3D d->cqm_work_cpu && + has_busy_rmid(d)) { + cancel_delayed_work(&d->cqm_limbo); + cqm_setup_limbo_handler(d, 0, cpu); + } + } } =20 /* --=20 2.20.1