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

Gavin Shan
2022-06-01T02:46:46Z

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@arm.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@redhat.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