linux-kernel - RE: [PATCH 4/4] selftests/resctrl: Adjust SNC support messages

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]

Date: Thu, 7 Mar 2024 21:14:35 +0000
From: "Luck, Tony" <tony.luck@...el.com>
To: "Chatre, Reinette" <reinette.chatre@...el.com>, "Wieczor-Retman, Maciej"
	<maciej.wieczor-retman@...el.com>
CC: "Yu, Fenghua" <fenghua.yu@...el.com>, Shuah Khan <shuah@...nel.org>,
	"james.morse@....com" <james.morse@....com>, "ilpo.jarvinen@...ux.intel.com"
	<ilpo.jarvinen@...ux.intel.com>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "linux-kselftest@...r.kernel.org"
	<linux-kselftest@...r.kernel.org>
Subject: RE: [PATCH 4/4] selftests/resctrl: Adjust SNC support messages

> Thinking about it even differently. The goal is to give information
> to userspace so we need to think about what would help user space?
> For example, what if there is a file in info that shows 
> which CPUs are associated with each domain?

Reinette,

Interesting idea. That would save users from having to chase through
/sys/devices/system/cpu/cpu*/cache/index?/* to figure out what the domain
numbers in schemata files and the mon_data/mon_L3_XX values mean.

May be extra useful for ARM which seems to have big random-looking numbers
for domains that came out of ACPI tables.

For SNC it would get the user directly to what they probably care about
(which CPUs are in which domain).

So something like this for an SNC 2 system:

$ cat /sys/fs/resctrl/info/L3/cpus
0: 0-35,72-107
1: 36-71,108-143

$ cat /sys/fs/resctrl/info/L3_MON/cpus
0: 0-17,72-89
1: 18-35,90-107
2: 36-53,108-125
3: 54-71,126-143

[maybe there is a better name than "cpus" for this file?]

-Tony