On 2/27/24 15:30, Eduard Zingerman wrote:
On Tue, 2024-02-27 at 15:16 -0800, Kui-Feng Lee wrote:
[...]
So, it appears that with shadow types users would have more or less
convenient way to disable / enable related BPF programs
(the references to programs are available, but reference counting
would have to be implemented by user using some additional data
structure, if needed).
I don't see a way to reconcile shadow types with this autoload/autocreate toggling
=> my last two patches would have to be dropped.
How about to update autoload according to the value of autocreate of
maps before loading the programs? For example, update autoload in
bpf_map__init_kern_struct_ops()?
This can be done, but it would have to be a separate pass:
first scanning all maps and setting up reference counters for programs,
then scanning all programs and disabling those unused.
I can do that in v2, thank you for the suggestion.
Still, this overlaps a bit with shadow types.
Do you have an idea if such auto-toggling would be helpful from libbpf
users point of view?
For me, it is useful. For minor adjustments, shadow types is easier and
simpler; for example, change a flag or a function. But, the features
presented here are useful when a user want to switch between several
very different configurations. They may not want to change a large
number of fields.
