On Mon, Jul 26, 2021 at 10:37:57PM +0530, Pratik R. Sampat wrote:
> In the numa=off kernel command-line configuration init_chip_info() loops
> around the number of chips and attempts to copy the cpumask of that node
> which is NULL for all iterations after the first chip.
>
> Hence, store the cpu mask for each chip instead of derving cpumask from
> node while populating the "chips" struct array and copy that to the
> chips[i].mask
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 053819e0bf84 ("cpufreq: powernv: Handle throttling due to Pmax capping at chip level")
> Signed-off-by: Pratik R. Sampat <psampat@xxxxxxxxxxxxx>
> Reported-by: Shirisha Ganta <shirisha.ganta1@xxxxxxx>
> ---
> drivers/cpufreq/powernv-cpufreq.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 005600cef273..8ec10d9aed8f 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -1046,12 +1046,20 @@ static int init_chip_info(void)
> unsigned int *chip;
> unsigned int cpu, i;
> unsigned int prev_chip_id = UINT_MAX;
> + cpumask_t *chip_cpu_mask;
> int ret = 0;
>
> chip = kcalloc(num_possible_cpus(), sizeof(*chip), GFP_KERNEL);
> if (!chip)
> return -ENOMEM;
>
> + /* Allocate a chip cpu mask large enough to fit mask for all chips */
> + chip_cpu_mask = kcalloc(32, sizeof(cpumask_t), GFP_KERNEL);
I suppose by 32 you mean the maximum number of chips possible. You
could use a #define for that.
Otherwise, the patch looks good to me.
Reviewed-by: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>
> + if (!chip_cpu_mask) {
> + ret = -ENOMEM;
> + goto free_and_return;
> + }
> +
> for_each_possible_cpu(cpu) {
> unsigned int id = cpu_to_chip_id(cpu);
>
> @@ -1059,22 +1067,25 @@ static int init_chip_info(void)
> prev_chip_id = id;
> chip[nr_chips++] = id;
> }
> + cpumask_set_cpu(cpu, &chip_cpu_mask[nr_chips-1]);
> }
>
> chips = kcalloc(nr_chips, sizeof(struct chip), GFP_KERNEL);
> if (!chips) {
> ret = -ENOMEM;
> - goto free_and_return;
> + goto out_chip_cpu_mask;
> }
>
> for (i = 0; i < nr_chips; i++) {
> chips[i].id = chip[i];
> - cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i]));
> + cpumask_copy(&chips[i].mask, &chip_cpu_mask[i]);
> INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn);
> for_each_cpu(cpu, &chips[i].mask)
> per_cpu(chip_info, cpu) = &chips[i];
> }
>
> +out_chip_cpu_mask:
> + kfree(chip_cpu_mask);
> free_and_return:
> kfree(chip);
> return ret;
> --
> 2.31.1
>
