2020-12-10 14:30:36

by Gautham R Shenoy

Subject: [PATCH v3 3/5] powerpc/smp: Rename init_thread_group_l1_cache_map() to make it generic

From: "Gautham R. Shenoy" <[email protected]>

init_thread_group_l1_cache_map() initializes the per-cpu cpumask
thread_group_l1_cache_map with the core-siblings which share L1 cache
with the CPU. Make this function generic to the cache-property (L1 or
L2) and update a suitable mask. This is a preparatory patch for the
next patch where we will introduce discovery of thread-groups that
share L2-cache.

No functional change.

Signed-off-by: Gautham R. Shenoy <[email protected]>
---
arch/powerpc/kernel/smp.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index f3290d5..9078b5b5 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -866,15 +866,18 @@ static struct thread_groups *__init get_thread_groups(int cpu,
return tg;
}

-static int init_thread_group_l1_cache_map(int cpu)
+static int __init init_thread_group_cache_map(int cpu, int cache_property)

{
int first_thread = cpu_first_thread_sibling(cpu);
int i, cpu_group_start = -1, err = 0;
struct thread_groups *tg = NULL;
+ cpumask_var_t *mask;

- tg = get_thread_groups(cpu, THREAD_GROUP_SHARE_L1,
- &err);
+ if (cache_property != THREAD_GROUP_SHARE_L1)
+ return -EINVAL;
+
+ tg = get_thread_groups(cpu, cache_property, &err);
if (!tg)
return err;

@@ -885,8 +888,8 @@ static int init_thread_group_l1_cache_map(int cpu)
return -ENODATA;
}

- zalloc_cpumask_var_node(&per_cpu(thread_group_l1_cache_map, cpu),
- GFP_KERNEL, cpu_to_node(cpu));
+ mask = &per_cpu(thread_group_l1_cache_map, cpu);
+ zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cpu));

for (i = first_thread; i < first_thread + threads_per_core; i++) {
int i_group_start = get_cpu_thread_group_start(i, tg);
@@ -897,7 +900,7 @@ static int init_thread_group_l1_cache_map(int cpu)
}

if (i_group_start == cpu_group_start)
- cpumask_set_cpu(i, per_cpu(thread_group_l1_cache_map, cpu));
+ cpumask_set_cpu(i, *mask);
}

return 0;
@@ -976,7 +979,7 @@ static int init_big_cores(void)
int cpu;

for_each_possible_cpu(cpu) {
- int err = init_thread_group_l1_cache_map(cpu);
+ int err = init_thread_group_cache_map(cpu, THREAD_GROUP_SHARE_L1);

if (err)
return err;
--
1.9.4

2020-12-15 08:46:48

by Srikar Dronamraju

Subject: Re: [PATCH v3 3/5] powerpc/smp: Rename init_thread_group_l1_cache_map() to make it generic

* Gautham R. Shenoy <[email protected]> [2020-12-10 16:08:57]:

> From: "Gautham R. Shenoy" <[email protected]>
>
> init_thread_group_l1_cache_map() initializes the per-cpu cpumask
> thread_group_l1_cache_map with the core-siblings which share L1 cache
> with the CPU. Make this function generic to the cache-property (L1 or
> L2) and update a suitable mask. This is a preparatory patch for the
> next patch where we will introduce discovery of thread-groups that
> share L2-cache.
>
> No functional change.
>

Looks good to me.

Reviewed-by: Srikar Dronamraju <[email protected]>

> Signed-off-by: Gautham R. Shenoy <[email protected]>
--
Thanks and Regards
Srikar Dronamraju