linux-kernel - Re: [PATCH v6 42/42] x86/resctrl: Add python script to move resctrl code to /fs/resctrl

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: <baa225e6-65bd-49ec-baf9-166ae4f2926c@intel.com>
Date: Wed, 19 Feb 2025 22:10:25 -0800
From: Reinette Chatre <reinette.chatre@...el.com>
To: James Morse <james.morse@....com>, <x86@...nel.org>,
	<linux-kernel@...r.kernel.org>
CC: 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>, Koba Ko <kobak@...dia.com>, Shanker
 Donthineni <sdonthineni@...dia.com>, Shaopeng Tan
	<tan.shaopeng@...fujitsu.com>, "Tony Luck" <tony.luck@...el.com>
Subject: Re: [PATCH v6 42/42] x86/resctrl: Add python script to move resctrl
 code to /fs/resctrl

Hi James,

On 2/7/25 10:18 AM, James Morse wrote:
> To support more than one architecture resctrl needs to move from arch/x86
> to live under fs. Moving all the code breaks any series on the mailing
> list, so needs scheduling carefully.
> 
> Maintaining the patch that moves all this code has proved labour intensive.
> It's also near-impossible to review that no inadvertent changes have
> crept in.
> 
> To solve these problems, temporarily add a hacky python program that
> lists all the functions that should move, and those that should stay.
> 
> No attempt to parse C code is made, this thing tries to name 'blocks'
> based on hueristics about the kernel coding style. It's fragile, but

(heuristics)

> good enough for its single use here.
> 
> This only exists to show I have nothing up my sleeve.
> I don't suggested this gets merged.
> 
> The patch this script generaets has the following corner cases:
(generates)

> * The original files are regenerated, which will add newlines that are
>   not present in the original file.
> * An trace-point header file the only contains boiler-plate is created
>   in the arch and filesystem code. The parser doesn't know how to remove
>   the includes for these - but its easy to 'keep' the file contents on
>   the correct side. A follow-up patch will remove these files and their
>   includes.

Related to the tracepoints I also noticed that there are some leftover
tracing defines in files that no longer make use of tracing.
For example, arch/x86/kernel/cpu/resctrl/monitor.c contains:
#define CREATE_TRACE_POINTS
#include monitor_trace.h

and fs/resctrl/pseudo_lock.c contains:
#define CREATE_TRACE_POINTS
#include "pseudo_lock_trace.h"

I assumed this will also be removed in this follow-up patch?

> * asm/cpu_device_id.h and a relative path for 'X86_CONFIG()' are kept
>   in the filesystem code to ensure x86 builds. A follow-up patch will
>   remove these.
> * This script doesn't know how to move the documentation, and update the
>   links in comments. A follow-up patch does this.

One unexpected thing I noticed is that fs/resctr/internal.h contains:
#ifndef _ASM_X86_RESCTRL_INTERNAL_H
#define _ASM_X86_RESCTRL_INTERNAL_H
...
#endif /* _ASM_X86_RESCTRL_INTERNAL_H */

Reinette