linux-kernel - Re: [PATCH 2/2] x86/resctrl: Fix memory bandwidth counter width for Hygon

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Message-ID: <9ec04c8a-c42d-4395-a8b0-c2569ce97272@open-hieco.net>
Date: Sun, 7 Dec 2025 00:19:57 +0800
From: Xiaochen Shen <shenxiaochen@...n-hieco.net>
To: Reinette Chatre <reinette.chatre@...el.com>,
 "Luck, Tony" <tony.luck@...el.com>, "bp@...en8.de" <bp@...en8.de>,
 "fenghuay@...dia.com" <fenghuay@...dia.com>
Cc: "babu.moger@....com" <babu.moger@....com>,
 "james.morse@....com" <james.morse@....com>,
 "Dave.Martin@....com" <Dave.Martin@....com>, "x86@...nel.org"
 <x86@...nel.org>, "linux-kernel@...r.kernel.org"
 <linux-kernel@...r.kernel.org>, shenxiaochen@...n-hieco.net
Subject: Re: [PATCH 2/2] x86/resctrl: Fix memory bandwidth counter width for
 Hygon

Hi Reinette,

On 12/6/2025 5:57 AM, Reinette Chatre wrote:
>> We have observed a test case where an incorrect counter width leads to random unexpected memory bandwidth readings:
>> https://github.com/shenxiaochen/my_documents/blob/main/memory_bandwidth_counter_width_and_overflow_issue_steps_to_reproduce.txt
> Could this perhaps be related to issue fixed by:
> 15292f1b4c55 ("x86/resctrl: Fix miscount of bandwidth event when reactivating previously unavailable RMID")?

Thank you for the information.
But I don't think this issue is related to commit 15292f1b4c55, which was already part of the code base when I discovered the problem.


Best regards,
Xiaochen Shen