| Date | Wed, 11 Dec 2013 16:38:40 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v0 23/71] perf evlist: Add perf_evlist__to_front() |
| |
Em Wed, Dec 11, 2013 at 02:36:35PM +0200, Alexander Shishkin escreveu: > From: Adrian Hunter <adrian.hunter@intel.com>
> Add a function to move a selected event to the front of the list.
> This is needed because it is not possible to use the > PERF_EVENT_IOC_SET_OUTPUT IOCTL from an Instruction Tracing event to a > non-Instruction Tracing event. Thus the Instruction Tracing event > must come first.
The description doesn't matches what the code is doing, as it is moving a _group_, not an event.
Also I wonder if you can't do this more effiently by finding where it starts, ends and then doing some more splice like operatins instead of moving member by member to a temp list. Setting the (next, prev) fields of the various sublists to the right places.
There is even list_cut_position() already in list.h, used with list_move() and list_splice() I think you can do it more efficiently, I think.
- Arnaldo
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/util/evlist.c | 17 +++++++++++++++++ > tools/perf/util/evlist.h | 3 +++ > 2 files changed, 20 insertions(+) > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > index f9dbf5f..93683bc 100644 > --- a/tools/perf/util/evlist.c > +++ b/tools/perf/util/evlist.c > @@ -1216,3 +1216,20 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused, > > return 0; > } > + > +void perf_evlist__to_front(struct perf_evlist *evlist, > + struct perf_evsel *move_evsel) > +{ > + struct perf_evsel *evsel, *n; > + LIST_HEAD(move); > + > + if (move_evsel == perf_evlist__first(evlist)) > + return; > + > + list_for_each_entry_safe(evsel, n, &evlist->entries, node) { > + if (evsel->leader == move_evsel->leader) > + list_move_tail(&evsel->node, &move); > + } > + > + list_splice(&move, &evlist->entries); > +} > diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h > index 8a04aae..9f64ede 100644 > --- a/tools/perf/util/evlist.h > +++ b/tools/perf/util/evlist.h > @@ -194,5 +194,8 @@ static inline void perf_mmap__write_tail(struct perf_mmap *md, > } > > bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str); > +void perf_evlist__to_front(struct perf_evlist *evlist, > + struct perf_evsel *move_evsel); > + > > #endif /* __PERF_EVLIST_H */ > -- > 1.8.5.1
|