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Message-ID: <fc437191-0fb6-92fc-c5c6-5387c254e065@intel.com>
Date:   Tue, 3 Oct 2023 14:23:09 -0700
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Subject: Re: [PATCH v6 22/24] x86/resctrl: Add cpu offline callback for
 resctrl work
Content-Language: en-US
To:     James Morse <james.morse@arm.com>, <x86@kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     Fenghua Yu <fenghua.yu@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        H Peter Anvin <hpa@zytor.com>,
        Babu Moger <Babu.Moger@amd.com>,
        <shameerali.kolothum.thodi@huawei.com>,
        D Scott Phillips OS <scott@os.amperecomputing.com>,
        <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 <quic_jiles@quicinc.com>,
        Xin Hao <xhao@linux.alibaba.com>, <peternewman@google.com>,
        <dfustini@baylibre.com>, <amitsinght@marvell.com>
References: <20230914172138.11977-1-james.morse@arm.com>
 <20230914172138.11977-23-james.morse@arm.com>
From:   Reinette Chatre <reinette.chatre@intel.com>
In-Reply-To: <20230914172138.11977-23-james.morse@arm.com>
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Hi James,

On 9/14/2023 10:21 AM, James Morse wrote:
> The resctrl architecture specific code may need to free a domain when
> a CPU goes offline, it also needs to reset the CPUs PQR_ASSOC register.
> Amongst other things, the resctrl filesystem code needs to clear this
> CPU from the cpu_mask of any control and monitor groups.
> 
> Currently this is all done in core.c and called from
> resctrl_offline_cpu(), making the split between architecture and
> filesystem code unclear.
> 
> Move the filesystem work to remove the CPU from the control and monitor
> groups into a filesystem helper called resctrl_offline_cpu(), and rename
> the one in core.c resctrl_arch_offline_cpu().
> 
> The rdtgroup_mutex is unlocked and locked again in the call in
> preparation for changing the locking rules for the architecture
> code.

This last paragraph may cause some confusion since this refactoring
is not changing any current locking. I'll defer to you if you prefer
to keep it.

> 
> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
> Tested-By: Peter Newman <peternewman@google.com>
> Signed-off-by: James Morse <james.morse@arm.com>
> ---

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette