linux-kernel - Re: [PATCH v8 07/25] x86/resctrl: Introduce the interface to display monitor mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZwcG2e90vXHlIVan@agluck-desk3.sc.intel.com>
Date: Wed, 9 Oct 2024 15:42:33 -0700
From: Tony Luck <tony.luck@...el.com>
To: Babu Moger <babu.moger@....com>
Cc: corbet@....net, fenghua.yu@...el.com, reinette.chatre@...el.com,
	tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
	dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
	paulmck@...nel.org, rdunlap@...radead.org, tj@...nel.org,
	peterz@...radead.org, yanjiewtw@...il.com, kim.phillips@....com,
	lukas.bulwahn@...il.com, seanjc@...gle.com, jmattson@...gle.com,
	leitao@...ian.org, jpoimboe@...nel.org, rick.p.edgecombe@...el.com,
	kirill.shutemov@...ux.intel.com, jithu.joseph@...el.com,
	kai.huang@...el.com, kan.liang@...ux.intel.com,
	daniel.sneddon@...ux.intel.com, pbonzini@...hat.com,
	sandipan.das@....com, ilpo.jarvinen@...ux.intel.com,
	peternewman@...gle.com, maciej.wieczor-retman@...el.com,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	eranian@...gle.com, james.morse@....com
Subject: Re: [PATCH v8 07/25] x86/resctrl: Introduce the interface to display
 monitor mode

On Wed, Oct 09, 2024 at 12:39:32PM -0500, Babu Moger wrote:
> +"mbm_assign_mode":
> +	Reports the list of monitoring modes supported. The enclosed brackets
> +	indicate which mode is enabled.
> +	::
> +
> +	  cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
> +	  [mbm_cntr_assign]
> +	  default
> +
> +	"mbm_cntr_assign":
> +
> +	In mbm_cntr_assign mode user-space is able to specify which control
> +	or monitor groups in resctrl should have a counter assigned using the
> +	'mbm_assign_control' file. The number of counters available is described
> +	in the 'num_mbm_cntrs' file. Changing the mode may cause all counters on
> +	a resource to reset.
> +
> +	The mode is useful on platforms which support more control and monitor
> +	groups than hardware counters, meaning 'unassigned' control or monitor
> +	groups will report 'Unavailable' or count the traffic in an unpredictable
> +	way.
> +
> +	AMD Platforms with ABMC (Assignable Bandwidth Monitoring Counters) feature
> +	enable this mode by default so that counters remain assigned even when the
> +	corresponding RMID is not in use by any processor.
> +
> +	"default":
> +
> +	By default resctrl assumes each control and monitor group has a hardware
> +	counter. Hardware that does not support 'mbm_cntr_assign' mode will still
> +	allow more control or monitor groups than 'num_rmids' to be created. In

Should that be s/num_rmids/num_mbm_cntrs/ ?

-Tony