Re: [PATCH 1/2] perf lock contention: Fix struct rq lock access

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Apr 27, 2023 at 05:32:08PM -0700, Ian Rogers escreveu:
> On Thu, Apr 27, 2023 at 4:48 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > The BPF CO-RE's ignore suffix rule requires three underscores.
> > Otherwise it'd fail like below:
> >
> >   $ sudo perf lock contention -ab
> >   libbpf: prog 'collect_lock_syms': BPF program load failed: Invalid argument
> >   libbpf: prog 'collect_lock_syms': -- BEGIN PROG LOAD LOG --
> >   reg type unsupported for arg#0 function collect_lock_syms#380
> >   ; int BPF_PROG(collect_lock_syms)
> >   0: (b7) r6 = 0                        ; R6_w=0
> >   1: (b7) r7 = 0                        ; R7_w=0
> >   2: (b7) r9 = 1                        ; R9_w=1
> >   3: <invalid CO-RE relocation>
> >   failed to resolve CO-RE relocation <byte_off> [381] struct rq__new.__lock (0:0 @ offset 0)
> >
> > Fixes: 0c1228486bef ("perf lock contention: Support pre-5.14 kernels")
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> 
> Acked-by: Ian Rogers <irogers@google.com>

Thanks, applied the series.

- Arnaldo

 
> Thanks,
> Ian
> 
> > ---
> >  tools/perf/util/bpf_skel/lock_contention.bpf.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
> > index 8911e2a077d8..30c193078bdb 100644
> > --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
> > +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
> > @@ -418,11 +418,11 @@ int contention_end(u64 *ctx)
> >
> >  extern struct rq runqueues __ksym;
> >
> > -struct rq__old {
> > +struct rq___old {
> >         raw_spinlock_t lock;
> >  } __attribute__((preserve_access_index));
> >
> > -struct rq__new {
> > +struct rq___new {
> >         raw_spinlock_t __lock;
> >  } __attribute__((preserve_access_index));
> >
> > @@ -434,8 +434,8 @@ int BPF_PROG(collect_lock_syms)
> >
> >         for (int i = 0; i < MAX_CPUS; i++) {
> >                 struct rq *rq = bpf_per_cpu_ptr(&runqueues, i);
> > -               struct rq__new *rq_new = (void *)rq;
> > -               struct rq__old *rq_old = (void *)rq;
> > +               struct rq___new *rq_new = (void *)rq;
> > +               struct rq___old *rq_old = (void *)rq;
> >
> >                 if (rq == NULL)
> >                         break;
> > --
> > 2.40.1.495.gc816e09b53d-goog
> >

-- 

- Arnaldo