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Message-ID: <d679a449-cd7f-b21c-2bad-e3c6aeb9a956@arm.com>
Date: Mon, 22 Jan 2024 18:06:27 +0000
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Subject: Re: [PATCH v8 19/24] x86/resctrl: Add helpers for system wide
 mon/alloc capable
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To: babu.moger@amd.com, x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Fenghua Yu <fenghua.yu@intel.com>,
 Reinette Chatre <reinette.chatre@intel.com>,
 Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
 Borislav Petkov <bp@alien8.de>, H Peter Anvin <hpa@zytor.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>
 <20231215174343.13872-20-james.morse@arm.com>
 <4283c1e1-5f3b-4e55-a40c-1a46b3d8e067@amd.com>
From: James Morse <james.morse@arm.com>
In-Reply-To: <4283c1e1-5f3b-4e55-a40c-1a46b3d8e067@amd.com>
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Hi Babu,

On 03/01/2024 19:43, Moger, Babu wrote:
> On 12/15/23 11:43, James Morse wrote:
>> resctrl reads rdt_alloc_capable or rdt_mon_capable to determine
>> whether any of the resources support the corresponding features.
>> resctrl also uses the static-keys that affect the architecture's
>> context-switch code to determine the same thing.
>>
>> This forces another architecture to have the same static-keys.
>>
>> As the static-key is enabled based on the capable flag, and none of
>> the filesystem uses of these are in the scheduler path, move the
>> capable flags behind helpers, and use these in the filesystem
>> code instead of the static-key.
>>
>> After this change, only the architecture code manages and uses
>> the static-keys to ensure __resctrl_sched_in() does not need
>> runtime checks.
>>
>> This avoids multiple architectures having to define the same
>> static-keys.
>>
>> Cases where the static-key implicitly tested if the resctrl
>> filesystem was mounted all have an explicit check added by a
>> previous patch.

> Reviewed-by: Babu Moger <babu.moger@amd.com>


Thanks!

James