On 09.11.2021 03:11, Stefano Stabellini wrote: > On Mon, 8 Nov 2021, Jan Beulich wrote: >> On 05.11.2021 16:33, Stefano Stabellini wrote: >>> My main concern is performance and resource utilization. With v3 of the >>> patch get_parent_handle will get called for every module to be loaded. >>> With dom0less, it could easily get called 10 times or more. Taking a >>> look at get_parent_handle, the Xen side doesn't seem small and I have >>> no idea how the EDK2 side looks. I am just worried that it would >>> actually have an impact on boot times (also depending on the bootloader >>> implementation). >> >> The biggest part of the function deals with determining the "residual" of >> the file name. That part looks to be of no interest at all to >> allocate_module_file() (whether that's actually correct I can't tell). I >> don't see why this couldn't be made conditional (e.g. by passing in NULL >> for "leaf"). > > I understand the idea of passing NULL instead of "leaf", but I tried > having a look and I can't tell what we would be able to skip in > get_parent_handle.
My bad - I did overlook that dir_handle gets updated even past the initial loop. > Should we have a global variable to keep the dir_handle open during > dom0less module loading? If that's contained within Arm-specific code, I (obviously) don't mind. Otherwise I remain to be convinced. Jan
