linux-kernel - Re: [RFC PATCH 03/19] fs/resctrl: Add new interface max

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Message-ID: <b7f04a29-0693-4df9-b0dd-c7c047c1f9fe@intel.com>
Date: Fri, 6 Feb 2026 15:58:35 -0800
From: Reinette Chatre <reinette.chatre@...el.com>
To: Babu Moger <babu.moger@....com>, <corbet@....net>, <tony.luck@...el.com>,
	<Dave.Martin@....com>, <james.morse@....com>, <tglx@...nel.org>,
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Subject: Re: [RFC PATCH 03/19] fs/resctrl: Add new interface max_bandwidth

Hi Babu,

On 1/21/26 1:12 PM, Babu Moger wrote:
> While min_bandwidth is exposed for each resource under
> /sys/fs/resctrl, the maximum supported bandwidth is not currently shown.
> 
> Add max_bandwidth to report the maximum bandwidth permitted for a resource.
> This helps users understand the limits of the associated resource control
> group.
> 
> Signed-off-by: Babu Moger <babu.moger@....com>
> ---

With resctrl fs being used by several architectures we should take care that
interface changes take all planned usages into account. 

As shared at LPC [1] and email [2] we are already trying to create an interface
that works for everybody and it already contains a way to expose the maximum
bandwidth to user space. You attended that LPC session and [2] directed to you
received no response. This submission with a different interface is unexpected.

Reinette

[1] https://lpc.events/event/19/contributions/2093/attachments/1958/4172/resctrl%20Microconference%20LPC%202025%20Tokyo.pdf
[2] https://lore.kernel.org/lkml/fb1e2686-237b-4536-acd6-15159abafcba@intel.com/