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

From: Gavin Shan
Date: Tue May 31 2022 - 22:45:33 EST


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@xxxxxxx>
---
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@xxxxxxxxxx>


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