On Sat, Aug 12, 2023 at 1:52 AM Yang Jihong <yangjihong1@huawei.com> wrote:
>
> work_push_atom() supports nesting. Currently, all supported kworks are not
> nested. A `overwrite` parameter is added to overwrite the original atom in
> the list.
>
> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
> ---
> tools/perf/builtin-kwork.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/builtin-kwork.c b/tools/perf/builtin-kwork.c
> index 42ea59a957ae..f620911a26a2 100644
> --- a/tools/perf/builtin-kwork.c
> +++ b/tools/perf/builtin-kwork.c
> @@ -392,9 +392,10 @@ static int work_push_atom(struct perf_kwork *kwork,
> struct evsel *evsel,
> struct perf_sample *sample,
> struct machine *machine,
> - struct kwork_work **ret_work)
> + struct kwork_work **ret_work,
> + bool overwrite)
kerneldoc would be useful. Pushing something seems self-evident but
what does overwrite mean without reading the code?
> {
> - struct kwork_atom *atom, *dst_atom;
> + struct kwork_atom *atom, *dst_atom, *last_atom;
> struct kwork_work *work, key;
>
> BUG_ON(class->work_init == NULL);
> @@ -427,6 +428,17 @@ static int work_push_atom(struct perf_kwork *kwork,
> if (ret_work != NULL)
> *ret_work = work;
>
> + if (overwrite) {
> + last_atom = list_last_entry_or_null(&work->atom_list[src_type],
> + struct kwork_atom, list);
> + if (last_atom) {
> + atom_del(last_atom);
> +
> + kwork->nr_skipped_events[src_type]++;
> + kwork->nr_skipped_events[KWORK_TRACE_MAX]++;
> + }
> + }
> +
> list_add_tail(&atom->list, &work->atom_list[src_type]);
>
> return 0;
> @@ -502,7 +514,7 @@ static int report_entry_event(struct perf_kwork *kwork,
> {
> return work_push_atom(kwork, class, KWORK_TRACE_ENTRY,
> KWORK_TRACE_MAX, evsel, sample,
> - machine, NULL);
> + machine, NULL, true);
nit: for constant arguments it can be useful to add parameter names
which can enable checks like clang-tidy's bugprone argument:
https://clang.llvm.org/extra/clang-tidy/checks/bugprone/argument-comment.html
This would make this:
return work_push_atom(kwork, class, KWORK_TRACE_ENTRY,
KWORK_TRACE_MAX, evsel, sample,
machine, /*ret_work=*/NULL, /*overwite=*/true);
Thanks,
Ian
> }
>
> static int report_exit_event(struct perf_kwork *kwork,
> @@ -557,7 +569,7 @@ static int latency_raise_event(struct perf_kwork *kwork,
> {
> return work_push_atom(kwork, class, KWORK_TRACE_RAISE,
> KWORK_TRACE_MAX, evsel, sample,
> - machine, NULL);
> + machine, NULL, true);
> }
>
> static int latency_entry_event(struct perf_kwork *kwork,
> @@ -716,7 +728,7 @@ static int timehist_raise_event(struct perf_kwork *kwork,
> {
> return work_push_atom(kwork, class, KWORK_TRACE_RAISE,
> KWORK_TRACE_MAX, evsel, sample,
> - machine, NULL);
> + machine, NULL, true);
> }
>
> static int timehist_entry_event(struct perf_kwork *kwork,
> @@ -730,7 +742,7 @@ static int timehist_entry_event(struct perf_kwork *kwork,
>
> ret = work_push_atom(kwork, class, KWORK_TRACE_ENTRY,
> KWORK_TRACE_RAISE, evsel, sample,
> - machine, &work);
> + machine, &work, true);
> if (ret)
> return ret;
>
> --
> 2.30.GIT
>