An auxiliary evlist is created by perf_evlist__new_aux() using an existing evlist as its parent. An auxiliary evlist can have its own 'struct perf_mmap', but can't have any other data. User should use its parent instead when accessing other data.
Auxiliary evlists are containers of 'struct perf_mmap'. It is introduced to allow its parent evlist to map different events into separated mmaps. The following commit creates an auxiliary evlist for overwritable events, because overwritable events need a read only and backwards ring buffer, which is different from normal events. To achieve this goal, this patch carefully changes 'evlist' to 'evlist->parent' in all functions in the path of 'perf_evlist__mmap_ex', except 'evlist->mmap' related operations, to make sure all evlist modifications (like pollfd and event id hash tables) goes to original evlist. A 'evlist->parent' pointer is added to 'struct perf_evlist' and points to the evlist itself for normal evlists. Signed-off-by: Wang Nan <wangn...@huawei.com> Cc: He Kuang <heku...@huawei.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Masami Hiramatsu <mhira...@kernel.org> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Link: http://lkml.kernel.org/r/1464056944-166978-2-git-send-email-wangn...@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/evlist.c | 31 +++++++++++++++++++++---------- tools/perf/util/evlist.h | 3 +++ 2 files changed, 24 insertions(+), 10 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 1b918aa..e8fcb22 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -45,6 +45,7 @@ void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus, fdarray__init(&evlist->pollfd, 64); evlist->workload.pid = -1; evlist->backward = false; + evlist->parent = evlist; } struct perf_evlist *perf_evlist__new(void) @@ -1012,7 +1013,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx, struct perf_evsel *evsel; int revent; - evlist__for_each(evlist, evsel) { + evlist__for_each(evlist->parent, evsel) { int fd; if (evsel->overwrite != (evlist->overwrite && evlist->backward)) @@ -1044,16 +1045,16 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx, * Therefore don't add it for polling. */ if (!evsel->system_wide && - __perf_evlist__add_pollfd(evlist, fd, idx, revent) < 0) { + __perf_evlist__add_pollfd(evlist->parent, fd, idx, revent) < 0) { perf_evlist__mmap_put(evlist, idx); return -1; } if (evsel->attr.read_format & PERF_FORMAT_ID) { - if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread, + if (perf_evlist__id_add_fd(evlist->parent, evsel, cpu, thread, fd) < 0) return -1; - perf_evlist__set_sid_idx(evlist, evsel, idx, cpu, + perf_evlist__set_sid_idx(evlist->parent, evsel, idx, cpu, thread); } } @@ -1094,13 +1095,13 @@ static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, struct mmap_params *mp) { int thread; - int nr_threads = thread_map__nr(evlist->threads); + int nr_threads = thread_map__nr(evlist->parent->threads); pr_debug2("perf event ring buffer mmapped per thread\n"); for (thread = 0; thread < nr_threads; thread++) { int output = -1; - auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, thread, + auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist->parent, thread, false); if (perf_evlist__mmap_per_evsel(evlist, thread, mp, 0, thread, @@ -1239,8 +1240,8 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, bool auxtrace_overwrite) { struct perf_evsel *evsel; - const struct cpu_map *cpus = evlist->cpus; - const struct thread_map *threads = evlist->threads; + const struct cpu_map *cpus = evlist->parent->cpus; + const struct thread_map *threads = evlist->parent->threads; struct mmap_params mp = { .prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), }; @@ -1248,7 +1249,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0) return -ENOMEM; - if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0) + if (evlist->parent->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist->parent) < 0) return -ENOMEM; evlist->overwrite = overwrite; @@ -1259,7 +1260,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len, auxtrace_pages, auxtrace_overwrite); - evlist__for_each(evlist, evsel) { + evlist__for_each(evlist->parent, evsel) { if ((evsel->attr.read_format & PERF_FORMAT_ID) && evsel->sample_id == NULL && perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0) @@ -1916,3 +1917,13 @@ perf_evlist__find_evsel_by_str(struct perf_evlist *evlist, return NULL; } + +struct perf_evlist *perf_evlist__new_aux(struct perf_evlist *parent) +{ + struct perf_evlist *evlist = zalloc(sizeof(*evlist)); + + if (evlist != NULL) + perf_evlist__init(evlist, parent->cpus, parent->threads); + evlist->parent = parent->parent; + return evlist; +} diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 68cb136..41e65ac 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -60,6 +60,7 @@ struct perf_evlist { struct perf_evsel *selected; struct events_stats stats; struct perf_env *env; + struct perf_evlist *parent; }; struct perf_evsel_str_handler { @@ -70,6 +71,8 @@ struct perf_evsel_str_handler { struct perf_evlist *perf_evlist__new(void); struct perf_evlist *perf_evlist__new_default(void); struct perf_evlist *perf_evlist__new_dummy(void); +struct perf_evlist *perf_evlist__new_aux(struct perf_evlist *); + void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus, struct thread_map *threads); void perf_evlist__exit(struct perf_evlist *evlist); -- 1.8.3.4
