Messages in this thread |  | | From | Yosry Ahmed <> | Date | Fri, 20 May 2022 02:13:03 -0700 | Subject | Re: [PATCH bpf-next v1 2/5] cgroup: bpf: add cgroup_rstat_updated() and cgroup_rstat_flush() kfuncs |
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On Fri, May 20, 2022 at 12:24 AM Tejun Heo <tj@kernel.org> wrote: > > On Fri, May 20, 2022 at 01:21:30AM +0000, Yosry Ahmed wrote: > > Add cgroup_rstat_updated() and cgroup_rstat_flush() kfuncs to bpf > > tracing programs. bpf programs that make use of rstat can use these > > functions to inform rstat when they update stats for a cgroup, and when > > they need to flush the stats. > > > > Signed-off-by: Yosry Ahmed <yosryahmed@google.com> > > Do patch 1 and 2 need to be separate? Also, can you explain and comment why > it's __weak?
I will squash them in the next version.
As for the declaration, I took the __weak annotation from Alexei's reply to the previous version. I thought it had something to do with how fentry progs attach to functions with BTF and all. When I try the same code with a static noinline declaration instead, fentry attachment fails to find the BTF type ID of bpf_rstat_flush. When I try it with just noinline (without __weak), the fentry program attaches, but is never invoked. I tried looking at the attach code but I couldn't figure out why this happens.
In retrospect, I should have given this more thought. It would be great if Alexei could shed some light on this.
> > Thanks.
> > -- > tejun
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