Re: [PATCH v7 8/8] perf record: Unmap overwrite evlist when event terminate

[Wangnan (F)]

On 2016/6/17 4:59, Arnaldo Carvalho de Melo wrote:

Em Wed, Jun 15, 2016 at 02:23:35AM +0000, Wang Nan escreveu:

When see POLLERR or POLLHUP, unmap ring buffer from both the main
evlist and overwrite evlist.

When you use an auxiliary evlist this makes evlist->parent be different
than evlist, right? So can't we just hide this from tools and do it all
in perf_evlist__filter_pollfd?

So we need to find all children from parent. Currently we can only track
parent from children. This is not enough. Although currently we can pass
rec->overwrite_evlist to the filter so perf_evlist__filter_pollfd knows
it should release mmaps from both evlists, if in future we have more than
one aux_evlists it doesn't work.

Thank you.

This way we will not need to expose perf_evlist__mmap_put(), etc.

I haven't tried to _actually_ do this, just asking from browsing the
patchkit and with the goal of hiding the internals of this thing inside
evlist.c as much as possible.

- Arnaldo

Signed-off-by: Wang Nan <wangn...@huawei.com>
Cc: He Kuang <heku...@huawei.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.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
---
  tools/perf/builtin-record.c | 30 +++++++++++++++++++++---------
  tools/perf/util/evlist.c    |  3 +--
  tools/perf/util/evlist.h    |  2 +-
  3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index b9094f0..ca6376c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -914,6 +914,26 @@ out:
        return err;
  }

+static void record__munmap_filtered(struct fdarray *fda, int fd, void *arg)

+{
+       struct record *rec = (struct record *)arg;
+
+       perf_evlist__mmap_put(rec->evlist, fda->priv[fd].idx);
+       if (rec->overwrite_evlist)
+               perf_evlist__mmap_put(rec->overwrite_evlist, fda->priv[fd].idx);
+}
+
+static int record__filter_pollfd(struct record *rec)
+{
+       /*
+        * Although we may have auxiliray evlist, there is
+        * only one pollfd, so we don't need to filter pollfd
+        * for auxiliray evlist.
+        */
+       return fdarray__filter(&rec->evlist->pollfd, POLLERR | POLLHUP,
+                              record__munmap_filtered, rec);
+}
+
  static int __cmd_record(struct record *rec, int argc, const char **argv)
  {
        int err;
@@ -1150,15 +1170,7 @@ static int __cmd_record(struct record *rec, int argc, 
const char **argv)
                                err = 0;
                        waking++;

- /*

-                        * Although we may have auxiliray evlist, there is
-                        * only one pollfd, so we don't need to filter pollfd
-                        * for auxiliray evlist.
-                        *
-                        * TODO: if an event is terminated (POLLERR | POLLHUP),
-                        * unmap mmaps for auxiliray evlist too.
-                        */
-                       if (perf_evlist__filter_pollfd(rec->evlist, POLLERR | 
POLLHUP) == 0)
+                       if (record__filter_pollfd(rec) == 0)
                                draining = true;
                }

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c

index e8fcb22..d43ee81 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -27,7 +27,6 @@
  #include <linux/log2.h>
  #include <linux/err.h>

-static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);

  static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx);

#define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))

@@ -863,7 +862,7 @@ static void perf_evlist__mmap_get(struct perf_evlist 
*evlist, int idx)
        atomic_inc(&evlist->mmap[idx].refcnt);
  }

-static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)

+void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)
  {
        struct perf_mmap *md = &evlist->mmap[idx];

diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h

index 41e65ac..ba5e006 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -141,7 +141,7 @@ union perf_event *perf_evlist__mmap_read_backward(struct 
perf_evlist *evlist,
  void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx);

void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx);

-
+void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);
  int perf_evlist__pause(struct perf_evlist *evlist);
  int perf_evlist__resume(struct perf_evlist *evlist);
  int perf_evlist__open(struct perf_evlist *evlist);
--
1.8.3.4