[lkml]   [2022]   [May]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH bpf-next v1 2/5] cgroup: bpf: add cgroup_rstat_updated() and cgroup_rstat_flush() kfuncs
On Fri, May 20, 2022 at 03:06:07PM +0530, Kumar Kartikeya Dwivedi wrote:
> With static noinline, the compiler will optimize away the function. With global
> noinline, it can still optimize away the call site, but will keep the function
> definition, so attach works. Therefore __weak is needed to ensure call is still
> emitted. With GCC __attribute__((noipa)) might have been more appropritate, but
> LLVM doesn't support it, so __weak is the next best thing supported by both with
> the same side effect.

Ah, okay, so it's to prevent compiler from optimizing away call to a noop
function by telling it that we don't know what the function might eventually
be. Thanks for the explanation. Yosry, can you please add a comment
explaining what's going on?



 \ /
  Last update: 2022-05-20 13:17    [W:0.102 / U:1.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site