On Mon, Sep 16 2024 at 15:20, Costa Shulyupin wrote:
> +/*
> + * housekeeping_update - change housekeeping.cpumasks[type] and propagate the
> + * change.
> + */
> +static int housekeeping_update(enum hk_type type, const struct cpumask *update)
> +{
> + struct {
> + struct cpumask changed;
> + struct cpumask enable;
> + struct cpumask disable;
> + } *masks;
> +
> + masks = kmalloc(sizeof(*masks), GFP_KERNEL);
> + if (!masks)
> + return -ENOMEM;
> +
> + lockdep_assert_cpus_held();
> + cpumask_xor(&masks->changed, housekeeping_cpumask(type), update);
> + cpumask_and(&masks->enable, &masks->changed, update);
> + cpumask_andnot(&masks->disable, &masks->changed, update);
> + cpumask_copy(housekeeping.cpumasks[type], update);
> + WRITE_ONCE(housekeeping.flags, housekeeping.flags | BIT(type));
So this sets the bit for the type
> + if (!static_branch_unlikely(&housekeeping_overridden))
> + static_key_enable_cpuslocked(&housekeeping_overridden.key);
What's the point of doing this on every iteration?
> + kfree(masks);
> +
> + return 0;
> +}
> +
> static int __init housekeeping_setup(char *str, unsigned long flags)
> {
> cpumask_var_t non_housekeeping_mask, housekeeping_staging;
> @@ -327,8 +357,11 @@ int housekeeping_exlude_isolcpus(const struct cpumask *isolcpus, unsigned long f
> /*
> * Reset housekeeping to bootup default
> */
> +
> + for_each_clear_bit(type, &boot_hk_flags, HK_TYPE_MAX)
> + housekeeping_update(type, cpu_possible_mask);
Even for those which are clear
> for_each_set_bit(type, &boot_hk_flags, HK_TYPE_MAX)
> - cpumask_copy(housekeeping.cpumasks[type], boot_hk_cpumask);
> + housekeeping_update(type, boot_hk_cpumask);
>
> WRITE_ONCE(housekeeping.flags, boot_hk_flags);
Just to overwrite them with boot_hk_flags afterwards. That does not make
any sense at all.
Thanks,
tglx
