Messages in this thread | | | Date | Mon, 18 Nov 2019 15:48:07 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH 2/2][v2] x86/resctrl: Add task resctrl information display |
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On Sat, Nov 16, 2019 at 11:01:12PM +0800, Ryan Chen wrote: > Right, we can return 'blank' to user and let the user to parse the information.
There is nothing to parse - the task doesn't belong to any groups. That's it.
> And there is a similar behavior in cgroup that, for kernel thread that > does not belong > to any cgroup, /proc/{pid}/cgroup just show 'blank' without returning an error.
By 'blank' I assume you mean the empty string '' ?
> Yes, only when PROC_FS is set, /proc/{pid}/resctrl > can be displayed. However, CPU_RESCTRL might not > depend on proc fs, it is possible that the CPU_RESCTRL > is enabled but without PROC_FS set. If I understand correctly, > CPU_RESCTRL is the 'root' config for X86_CPU_RESCTRL, > after reading this thread: > https://lists.gt.net/linux/kernel/3211659
I'm not sure I know what you mean here. There's no CPU_RESCTRL option - you've added it in the previous patch:
[ ~/kernel/linux> git grep -E CONFIG_CPU_RESCTRL [ ~/kernel/linux> git grep -E "\WCPU_RESCTRL" [ ~/kernel/linux>
And if you want to use that option in proc/, then it needs to depend on PROC_FS, like the the example I gave you with CONFIG_PROC_PID_ARCH_STATUS.
Or do you mean something else?
> If this is the case, shall we add the new file at kernel/resctrl/resctrl.c? > And the generic proc_resctrl_show() could be put into this file. In the future > the generic code for resctrl could be added/moved to kernel/resctrl/resctrl.c
Not worth it for a single function. Leave it in arch/x86/kernel/cpu/resctrl/rdtgroup.c where you had it.
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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