Re: [PATCH bpf-next] bpf: Cache the last valid build_id.

[Hao Luo]

On Wed, Feb 23, 2022 at 3:16 PM Greg Thelen <gthelen@xxxxxxxxxx> wrote:
>
> Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:
>
> >
> > as a further optimization, shouldn't we first check if ips[i] is
> > within prev_vma and avoid rbtree walk altogether? Would this work:
> >
> > if (prev_vma && range_in_vma(prev_vma, ips[i])) {
> >    /* reuse build_id */
> > }
> > vma = find_vma(current->mm, ips[i]);
> >
> >
> > ?
>
> Yes, that's a nice addition. Good idea.

Yes, great point!

I noticed range_in_vma() already has a check on the null-ness of
prev_vma. I am going to send a v2.