On Sat, Aug 12, 2023 at 1:52 AM Yang Jihong <yangjihong1@xxxxxxxxxx> 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@xxxxxxxxxx>
---
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?
Thanks for your advice, will add parameter names later.
{
- 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);