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

Sudeep Holla
2022-06-01T12:46:59Z

On Wed, Jun 01, 2022 at 10:44:20AM +0800, Gavin Shan wrote:
> 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);
>

Right, I clearly missed to identify this. Thanks again for the review, all
other comments are now fixed locally and pushed @[1], will post them as part
of next version.

--
Regards,
Sudeep

[1] https://git.kernel.org/sudeep.holla/h/arch_topology