Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable
From:   Qian Cai <cai@lca.pw>
Mime-Version: 1.0 (1.0)
Subject: Re: [PATCH] x86/resctrl: fix an imbalance in domain_remove_cpu
Date:   Tue, 10 Dec 2019 14:08:38 -0500
Message-Id: <35666437-F8AF-4170-A00F-79C34370BEF0@lca.pw>
References: <37341135-a0db-6d1c-236f-e32461b4c398@intel.com>
Cc:     Ryan Chen <yu.chen.surf@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Fenghua Yu <fenghua.yu@intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        John Stultz <john.stultz@linaro.org>, sboyd@kernel.org,
        Tony Luck <tony.luck@intel.com>, tj@kernel.org,
        the arch/x86 maintainers <x86@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
In-Reply-To: <37341135-a0db-6d1c-236f-e32461b4c398@intel.com>
To:     Reinette Chatre <reinette.chatre@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


> On Dec 10, 2019, at 1:44 PM, Reinette Chatre <reinette.chatre@intel.com> w=
rote:
>=20
>=20
> "A system that supports resource monitoring may have multiple resources
> while not all of these resources are capable of monitoring. Monitoring
> related state is initialized only for resources that are capable of
> monitoring and correspondingly this state should subsequently only be
> removed from these resources that are capable of monitoring.
>=20
> domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
> is true where it will initialize d->mbm_over. However,
> domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
> checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
> all resources, even those that never initialized d->mbm_over because
> they are not capable of monitoring. Hence, it triggers a debugobjects
> warning when offlining CPUs because those timer debugobjects are never
> initialized.
>=20
> ODEBUG:..."

Looks better to me. Do you want me to send a v2 for it or you could update i=
t for merging?=