[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <b4765250-eb0f-4306-bb4d-45f45f1a0a04@intel.com>
Date: Tue, 13 Aug 2024 21:02:28 -0700
From: Reinette Chatre <reinette.chatre@...el.com>
To: James Morse <james.morse@....com>, <x86@...nel.org>,
<linux-kernel@...r.kernel.org>
CC: Fenghua Yu <fenghua.yu@...el.com>, Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, H Peter Anvin
<hpa@...or.com>, Babu Moger <Babu.Moger@....com>,
<shameerali.kolothum.thodi@...wei.com>, D Scott Phillips OS
<scott@...amperecomputing.com>, <carl@...amperecomputing.com>,
<lcherian@...vell.com>, <bobo.shaobowang@...wei.com>,
<tan.shaopeng@...itsu.com>, <baolin.wang@...ux.alibaba.com>, Jamie Iles
<quic_jiles@...cinc.com>, Xin Hao <xhao@...ux.alibaba.com>,
<peternewman@...gle.com>, <dfustini@...libre.com>, <amitsinght@...vell.com>,
David Hildenbrand <david@...hat.com>, Rex Nie <rex.nie@...uarmicro.com>,
"Dave Martin" <dave.martin@....com>
Subject: Re: [PATCH v4 23/39] x86/resctrl: Allow an architecture to disable
pseudo lock
Hi James,
On 8/2/24 10:28 AM, James Morse wrote:
> Pseudo-lock relies on knowledge of the micro-architecture to disable
> prefetchers etc.
>
> On arm64 these controls are typically secure only, meaning linux can't
> access them. Arm's cache-lockdown feature works in a very different
> way. Resctrl's pseudo-lock isn't going to be used on arm64 platforms.
>
> Add a Kconfig symbol that can be selected by the architecture. This
> enables or disables building of the pseudo_lock.c file, and replaces
> the functions with stubs. An additional IS_ENABLED() check is needed
> in rdtgroup_mode_write() so that attempting to enable pseudo-lock
> reports an "Unknown or unsupported mode" to user-space via the
> last_cmd file.
"last_cmd file" -> "last_cmd_status file"
Reinette
Powered by blists - more mailing lists