[PATCH 06/37] perf tools: Introduce perf_evlist__mmap_multi()

From: Namhyung Kim
Date: Wed Dec 24 2014 - 02:23:31 EST


The perf_evlist__mmap_multi function creates data mmaps and optionally
tracking mmaps for events. It'll be used for perf record to save
tracking events in a separate files. Checking dummy tracking event in
perf_evlist__mmap() alone is not enough as users can specify the dummy
event at first (like in keep tracking testcase) without the multi-file
option.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 3 ++-
tools/perf/util/evlist.c | 11 +++++++----
tools/perf/util/evlist.h | 10 ++++++++--
3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 129fab35fdc5..8c91f25b81f6 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -169,7 +169,8 @@ static int record__open(struct record *rec)
goto out;
}

- if (perf_evlist__mmap(evlist, opts->mmap_pages, false) < 0) {
+ if (perf_evlist__mmap_multi(evlist, opts->mmap_pages, false,
+ opts->multi_file) < 0) {
if (errno == EPERM) {
pr_err("Permission error mapping pages.\n"
"Consider increasing "
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index d99343b988fe..010188939104 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -841,6 +841,7 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool track_mmap)

struct mmap_params {
int prot;
+ bool track;
size_t len;
};

@@ -889,7 +890,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,

fd = FD(evsel, cpu, thread);

- if (perf_evsel__is_dummy_tracking(evsel)) {
+ if (mp->track && perf_evsel__is_dummy_tracking(evsel)) {
struct mmap_params track_mp = {
.prot = mp->prot,
.len = TRACK_MMAP_SIZE,
@@ -1068,10 +1069,11 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
}

/**
- * perf_evlist__mmap - Create mmaps to receive events.
+ * perf_evlist__mmap_multi - Create mmaps to receive events.
* @evlist: list of events
* @pages: map length in pages
* @overwrite: overwrite older events?
+ * @use_track_mmap: use another mmaps to track meta events
*
* If @overwrite is %false the user needs to signal event consumption using
* perf_mmap__write_tail(). Using perf_evlist__mmap_read() does this
@@ -1079,14 +1081,15 @@ int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
*
* Return: %0 on success, negative error code otherwise.
*/
-int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
- bool overwrite)
+int perf_evlist__mmap_multi(struct perf_evlist *evlist, unsigned int pages,
+ bool overwrite, bool use_track_mmap)
{
struct perf_evsel *evsel;
const struct cpu_map *cpus = evlist->cpus;
const struct thread_map *threads = evlist->threads;
struct mmap_params mp = {
.prot = PROT_READ | (overwrite ? 0 : PROT_WRITE),
+ .track = use_track_mmap,
};

if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist, use_track_mmap) < 0)
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index b7f54b8577f7..65c1aea6a3a4 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -127,10 +127,16 @@ int perf_evlist__parse_mmap_pages(const struct option *opt,
const char *str,
int unset);

-int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
- bool overwrite);
+int perf_evlist__mmap_multi(struct perf_evlist *evlist, unsigned int pages,
+ bool overwrite, bool use_track_mmap);
void perf_evlist__munmap(struct perf_evlist *evlist);

+static inline int perf_evlist__mmap(struct perf_evlist *evlist,
+ unsigned int pages, bool overwrite)
+{
+ return perf_evlist__mmap_multi(evlist, pages, overwrite, false);
+}
+
void perf_evlist__disable(struct perf_evlist *evlist);
void perf_evlist__enable(struct perf_evlist *evlist);

--
2.1.3

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