linux-kernel - Re: [PATCH v3 02/16] cacheinfo: Add helper to access any cache index for a given CPU

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: <9a70f2b2-e45c-b125-1c14-d5a06097be58@redhat.com>
Date:   Wed, 1 Jun 2022 10:44:20 +0800
From:   Gavin Shan <gshan@...hat.com>
To:     Sudeep Holla <sudeep.holla@....com>, linux-kernel@...r.kernel.org
Cc:     Atish Patra <atishp@...shpatra.org>,
        Atish Patra <atishp@...osinc.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Qing Wang <wangqing@...o.com>,
        linux-arm-kernel@...ts.infradead.org,
        linux-riscv@...ts.infradead.org, Rob Herring <robh+dt@...nel.org>
Subject: Re: [PATCH v3 02/16] cacheinfo: Add helper to access any cache index
 for a given CPU

Hi Sudeep,

On 5/25/22 4:14 PM, Sudeep Holla wrote:
> The cacheinfo for a given CPU at a given index is used at quite a few
> places by fetching the base point for index 0 using the helper
> per_cpu_cacheinfo(cpu) and offseting it by the required index.
> 
> Instead, add another helper to fetch the required pointer directly and
> use it to simplify and improve readability.
> 
> Signed-off-by: Sudeep Holla <sudeep.holla@....com>
> ---
>   drivers/base/cacheinfo.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 

s/offseting/offsetting

It looks good to me with below nits fixed:

Reviewed-by: Gavin Shan <gshan@...hat.com>


> diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
> index b0bde272e2ae..c4547d8ac6f3 100644
> --- a/drivers/base/cacheinfo.c
> +++ b/drivers/base/cacheinfo.c
> @@ -25,6 +25,8 @@ static DEFINE_PER_CPU(struct cpu_cacheinfo, ci_cpu_cacheinfo);
>   #define ci_cacheinfo(cpu)	(&per_cpu(ci_cpu_cacheinfo, cpu))
>   #define cache_leaves(cpu)	(ci_cacheinfo(cpu)->num_leaves)
>   #define per_cpu_cacheinfo(cpu)	(ci_cacheinfo(cpu)->info_list)
> +#define per_cpu_cacheinfo_idx(cpu, idx)		\
> +				(per_cpu_cacheinfo(cpu) + (idx))
>   
>   struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu)
>   {
> @@ -172,7 +174,7 @@ static int cache_setup_of_node(unsigned int cpu)
>   	}
>   
>   	while (index < cache_leaves(cpu)) {
> -		this_leaf = this_cpu_ci->info_list + index;
> +		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
>   		if (this_leaf->level != 1)
>   			np = of_find_next_cache_node(np);
>   		else
> @@ -231,7 +233,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
>   	for (index = 0; index < cache_leaves(cpu); index++) {
>   		unsigned int i;
>   
> -		this_leaf = this_cpu_ci->info_list + index;
> +		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
>   		/* skip if shared_cpu_map is already populated */
>   		if (!cpumask_empty(&this_leaf->shared_cpu_map))
>   			continue;
> @@ -242,7 +244,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
>   
>   			if (i == cpu || !sib_cpu_ci->info_list)
>   				continue;/* skip if itself or no cacheinfo */
> -			sib_leaf = sib_cpu_ci->info_list + index;
> +			sib_leaf = per_cpu_cacheinfo_idx(i, index);
>   			if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
>   				cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
>   				cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
> @@ -258,12 +260,11 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
>   
>   static void cache_shared_cpu_map_remove(unsigned int cpu)
>   {
> -	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
>   	struct cacheinfo *this_leaf, *sib_leaf;
>   	unsigned int sibling, index;
>   
>   	for (index = 0; index < cache_leaves(cpu); index++) {
> -		this_leaf = this_cpu_ci->info_list + index;
> +		this_leaf = per_cpu_cacheinfo_idx(cpu, index);
>   		for_each_cpu(sibling, &this_leaf->shared_cpu_map) {
>   			struct cpu_cacheinfo *sib_cpu_ci;
> 

In cache_shared_cpu_map_remove(), the newly introduced macro
can be applied when the sibling CPU's cache info is fetched.

     sib_leaf = sib_cpu_ci->info_list + index;

     to

     sib_leaf = per_cpu_cacheinfo_idx(sibling, index);

   
> @@ -609,7 +610,6 @@ static int cache_add_dev(unsigned int cpu)
>   	int rc;
>   	struct device *ci_dev, *parent;
>   	struct cacheinfo *this_leaf;
> -	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
>   	const struct attribute_group **cache_groups;
>   
>   	rc = cpu_cache_sysfs_init(cpu);
> @@ -618,7 +618,7 @@ static int cache_add_dev(unsigned int cpu)
>   
>   	parent = per_cpu_cache_dev(cpu);
>   	for (i = 0; i < cache_leaves(cpu); i++) {
> -		this_leaf = this_cpu_ci->info_list + i;
> +		this_leaf = per_cpu_cacheinfo_idx(cpu, i);
>   		if (this_leaf->disable_sysfs)
>   			continue;
>   		if (this_leaf->type == CACHE_TYPE_NOCACHE)
> 

Thanks,
Gavin