On Mon, Feb 14, 2022 at 2:31 PM Alyssa Rosenzweig alyssa.rosenzweig@collabora.com wrote:
MT8192 requires 5 power domains. Rather than bump MAX_PM_DOMAINS and waste memory on every supported Panfrost chip, instead dynamically allocate pm_domain_devs and pm_domain_links. This adds some flexibility; it seems inevitable a new MediaTek device will require more than 5 domains.
On non-MediaTek devices, this saves a small amount of memory.
How much? You measured it?
It's not that simple. kmalloc has finite allocation sizes (see /proc/slabinfo). So unless panfrost_device shrinks or grows to the next smaller or larger size, the memory used doesn't change. And each devm_kmalloc adds its own overhead as well.
I'd do the oneliner changing it to 5 and be done with it. That being said, we have plenty of examples of doing this both ways, so whatever makes people happy.
Rob