linux-kernel - Re: [sos-linux-ext-patches] [PATCH v2 1/6] sched/stats: Print domain name in /proc/schedstat

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: <12995871-3186-4265-b1f5-520252b9757f@amd.com>
Date: Fri, 22 Nov 2024 14:25:22 +0530
From: "Sapkal, Swapnil" <swapnil.sapkal@....com>
To: <peterz@...radead.org>, <mingo@...hat.com>, <acme@...nel.org>,
	<namhyung@...nel.org>, <irogers@...gle.com>, <james.clark@....com>
CC: <ravi.bangoria@....com>, <yu.c.chen@...el.com>, <mark.rutland@....com>,
	<alexander.shishkin@...ux.intel.com>, <jolsa@...nel.org>,
	<rostedt@...dmis.org>, <vincent.guittot@...aro.org>,
	<adrian.hunter@...el.com>, <kan.liang@...ux.intel.com>,
	<gautham.shenoy@....com>, <kprateek.nayak@....com>, <juri.lelli@...hat.com>,
	<yangjihong@...edance.com>, <void@...ifault.com>, <tj@...nel.org>,
	<vineethr@...ux.ibm.com>, <linux-kernel@...r.kernel.org>,
	<linux-perf-users@...r.kernel.org>, <santosh.shukla@....com>,
	<ananth.narayan@....com>, <sandipan.das@....com>, James Clark
	<james.clark@...aro.org>
Subject: Re: [sos-linux-ext-patches] [PATCH v2 1/6] sched/stats: Print domain
 name in /proc/schedstat

On 11/22/2024 2:14 PM, Swapnil Sapkal wrote:
> From: K Prateek Nayak <kprateek.nayak@....com>
> 
> Currently, there does not exist a straightforward way to extract the
> names of the sched domains and match them to the per-cpu domain entry in
> /proc/schedstat other than looking at the debugfs files which are only
> visible after enabling "verbose" debug after commit 34320745dfc9
> ("sched/debug: Put sched/domains files under the verbose flag")
> 
> Since tools like `perf sched schedstat` require displaying per-domain
> information in user friendly manner, display the names of sched domain,
> alongside their level in /proc/schedstat if CONFIG_SCHED_DEBUG is enabled.
> 
> Domain names also makes the /proc/schedstat data unambiguous when some
> of the cpus are offline. For example, on a 128 cpus AMD Zen3 machine
> where CPU0 and CPU64 are SMT siblings and CPU64 is offline:
> 
> Before:
>      cpu0 ...
>      domain0 ...
>      domain1 ...
>      cpu1 ...
>      domain0 ...
>      domain1 ...
>      domain2 ...
> 
> After:
>      cpu0 ...
>      domain0:MC ...
>      domain1:PKG ...
>      cpu1 ...
>      domain0:SMT ...
>      domain1:MC ...
>      domain2:PKG ...
> 
> schedstat version has not been updated since this change merely adds
> additional information to the domain name field and does not add a new
> field altogether.
> 
> Signed-off-by: K Prateek Nayak <kprateek.nayak@....com>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@....com>
> Tested-by: James Clark <james.clark@...aro.org>

Signed-off-by: Swapnil Sapkal <swapnil.sapkal@....com>