when you change the prototype to 'const void *' does it help compiler
to unroll it?

On Tue, Dec 13, 2016 at 12:06 PM, Mauricio Vasquez via iovisor-dev
<[email protected]> wrote:
> Hello,
>
> We are having some doubts about the use of the const qualifier for the key
> argument in functions to access eBPF maps, both, from user space and within
> eBPF programs.
>
> According to our understanding the key is not modified when used to access
> the maps, however we  noticed that in the bpf_*_elem functions [1] and in
> the array_map_*_elem functions [2] the const qualifier is not used. Is there
> any particular reason for avoid using it?
>
> An additional question: how is the prototype of the map.lookup function
> provided by bcc generated?
>
> We are asking it because we think that the lack of the const qualifier is
> causing some problems in the loop unrolling procedure [3].
>
> Thank you very much,
>
> Mauricio
>
> [1]
> https://github.com/torvalds/linux/blob/master/samples/bpf/libbpf.h#L9-L11
>
> [2] https://github.com/torvalds/linux/blob/master/kernel/bpf/arraymap.c#L110
>
> [3]
> https://lists.iovisor.org/pipermail/iovisor-dev/2016-December/000539.html
>
>
>
>
> _______________________________________________
> iovisor-dev mailing list
> [email protected]
> https://lists.iovisor.org/mailman/listinfo/iovisor-dev
>
_______________________________________________
iovisor-dev mailing list
[email protected]
https://lists.iovisor.org/mailman/listinfo/iovisor-dev

Reply via email to