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Message-ID: <802e84b7-ff12-19df-cb72-6cf307c7d67a@arm.com>
Date: Mon, 22 Jan 2024 18:05:26 +0000
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Subject: Re: [PATCH v8 05/24] x86/resctrl: Track the closid with the rmid
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To: Reinette Chatre <reinette.chatre@intel.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,
 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: <20231215174343.13872-1-james.morse@arm.com>
 <20231215174343.13872-6-james.morse@arm.com>
 <e54dedf6-158f-4553-b309-e4c61d69587a@intel.com>
From: James Morse <james.morse@arm.com>
In-Reply-To: <e54dedf6-158f-4553-b309-e4c61d69587a@intel.com>
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Hi Reinette,

On 16/12/2023 04:58, Reinette Chatre wrote:
> On 12/15/2023 9:43 AM, James Morse wrote:
>> x86's RMID are independent of the CLOSID. An RMID can be allocated,
>> used and freed without considering the CLOSID.
>>
>> MPAM's equivalent feature is PMG, which is not an independent number,
>> it extends the CLOSID/PARTID space. For MPAM, only PMG-bits worth of
>> 'RMID' can be allocated for a single CLOSID.
>> i.e. if there is 1 bit of PMG space, then each CLOSID can have two
>> monitor groups.
>>
>> To allow resctrl to disambiguate RMID values for different CLOSID,
>> everything in resctrl that keeps an RMID value needs to know the CLOSID
>> too. This will always be ignored on x86.
> 
> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>


Thanks!

James