On Fri, Jun 06, 2025 at 03:26:13PM +0100, Igor Korotin wrote: > On Fri, Jun 6, 2025 at 2:50 PM Danilo Krummrich <dakr@xxxxxxxxxx> wrote: > > However, I don't understand why we need this and the subsequent > > is_acpi_device_node() and is_of_node() checks. > > The idea is to avoid unnecessary table lookups when both OF and ACPI > match tables are present. If we already know the fwnode type, these > simple pointer comparisons (is_acpi_device_node() / is_of_node()) let > us skip the irrelevant match function. > > Those checks are cheap (just pointer comparisons), while > acpi_match_device() and of_match_device() iterate over tables. > > So yeah, it’s a bit ugly, but it can save some CPU cycles during enumeration. You have loads of CPU cycles during enumeration, keep things simple first, only attempt to optimize things later on if it is actually measureable. thanks, greg k-h
