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Date: Thu, 6 Jun 2024 14:43:08 +0200
From: Borislav Petkov <bp@alien8.de>
To: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org, Fenghua Yu <fenghua.yu@intel.com>,
	Reinette Chatre <reinette.chatre@intel.com>,
	Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>,
	Peter Newman <peternewman@google.com>,
	James Morse <james.morse@arm.com>, Babu Moger <babu.moger@amd.com>,
	Drew Fustini <dfustini@baylibre.com>,
	Dave Martin <Dave.Martin@arm.com>, linux-kernel@vger.kernel.org,
	patches@lists.linux.dev
Subject: Re: [PATCH v2 3/3] x86/resctrl: Replace open code cacheinfo search
 in rdtgroup_cbm_to_size()
Message-ID: <20240606124308.GCZmGu3Aj3_spSd0WS@fat_crate.local>
References: <20240605161427.312994-1-tony.luck@intel.com>
 <20240605161427.312994-4-tony.luck@intel.com>
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In-Reply-To: <20240605161427.312994-4-tony.luck@intel.com>

On Wed, Jun 05, 2024 at 09:14:27AM -0700, Tony Luck wrote:
> Use get_cpu_cacheinfo_level() instead of open coded search.
> 
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
> ---
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c | 14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 02f213f1c51c..cb68a121dabb 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1450,18 +1450,14 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
>  unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
>  				  struct rdt_domain *d, unsigned long cbm)
>  {
> -	struct cpu_cacheinfo *ci;
>  	unsigned int size = 0;
> -	int num_b, i;
> +	struct cacheinfo *ci;
> +	int num_b;
>  
>  	num_b = bitmap_weight(&cbm, r->cache.cbm_len);
> -	ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
> -	for (i = 0; i < ci->num_leaves; i++) {
> -		if (ci->info_list[i].level == r->cache_level) {
> -			size = ci->info_list[i].size / r->cache.cbm_len * num_b;
> -			break;
> -		}
> -	}
> +	ci = get_cpu_cacheinfo_level(cpumask_any(&d->cpu_mask), r->cache_level);
> +	if (ci)
> +		size = ci->size / r->cache.cbm_len * num_b;
>  
>  	return size;
>  }
> -- 

Those last two patches can be a single one which replaces open-coded
cacheinfo search in resctrl.

Or is there any particular reason for them to be separate?

Because it is a single logical change...

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette