linux-kernel - Re: [RFC v2 PATCH 7/7] x86/resctrl: Add debug files when mounted with debug option

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Date:   Thu, 16 Feb 2023 17:50:17 -0800
From:   Fenghua Yu <fenghua.yu@...el.com>
To:     Babu Moger <babu.moger@....com>, <reinette.chatre@...el.com>
CC:     <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
        <dave.hansen@...ux.intel.com>, <x86@...nel.org>, <hpa@...or.com>,
        <corbet@....net>, <linux-kernel@...r.kernel.org>,
        <linux-doc@...r.kernel.org>, <eranian@...gle.com>,
        <peternewman@...gle.com>
Subject: Re: [RFC v2 PATCH 7/7] x86/resctrl: Add debug files when mounted with
 debug option

Hi, Babu,

On 2/2/23 13:47, Babu Moger wrote:
> Add the debug files to the resctrl hierarchy.
> 
> Signed-off-by: Babu Moger <babu.moger@....com>
> ---
>   arch/x86/kernel/cpu/resctrl/rdtgroup.c |   27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index c35d91b04de6..b7c72b011264 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -2398,6 +2398,31 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
>   			     struct rdtgroup *prgrp,
>   			     struct kernfs_node **mon_data_kn);
>   
> +void resctrl_add_debug_file(struct kernfs_node *parent_kn,
> +			    const char *config, unsigned long fflags,
> +			    bool debug)
> +{
> +	struct rftype *rft;
> +
> +	rft = rdtgroup_get_rftype_by_name(config);
> +	if (debug && rft) {
> +		rft->fflags |= fflags;
> +		rdtgroup_add_file(parent_kn, rft);
> +	} else if (rft) {
> +		rft->fflags &= ~fflags;
> +		kernfs_remove_by_name(parent_kn, config);
> +	}
> +}
> +
> +static void resctrl_add_debug_files(bool debug)
> +{
> +	resctrl_add_debug_file(rdtgroup_default.kn, "rmid",
> +			       RFTYPE_BASE, debug);
> +	resctrl_add_debug_file(rdtgroup_default.kn, "closid",
> +			       RFTYPE_BASE_CTRL, debug);
> +	kernfs_activate(rdtgroup_default.kn);
> +}
> +
>   static int rdt_enable_ctx(struct rdt_fs_context *ctx)
>   {
>   	int ret = 0;
> @@ -2411,6 +2436,8 @@ static int rdt_enable_ctx(struct rdt_fs_context *ctx)
>   	if (!ret && ctx->enable_mba_mbps)
>   		ret = set_mba_sc(true);
>    > +	resctrl_add_debug_files(ctx->debug);

It's better to change to:
+	if (ctx->debug)
+		resctrl_add_debug_files();

Then the functions in the call chain can remove 'debug' parameter and 
can be simpler.
> +
>   	return ret;
>   }
>   
> 
> 
Thanks.

-Fenghua