# \[PATCH 0/3\] libperf: Add support for scaling counters obtained from the read() system call during multiplexing

- From: Shunsuke Nakamura \<hidden\>
- Date: 2021-08-20 09:46:39 
- List: linux-perf-users
- Page: https://ratatoskr.run/linux-perf-users/2021/08/1483729
- Thread: https://ratatoskr.run/linux-perf-users/2021/08/1483729/t.md

```text
This patch series supports counter scaling when perf_evsel__read() obtains a counter
using the read() system call during multiplexing.

The first patch adds scaling of counters obtained from the read() system call
during multiplexing.

The second patch fixes verbose printing.

The third patch adds a test for the first patch.
This patch is based on Vince's rdpmc_multiplexing.c [1]


[1] https://github.com/deater/perf_event_tests/blob/master/tests/rdpmc/rdpmc_multiplexing.c


Shunsuke Nakamura (3):
  libperf: Add processing to scale the counters obtained during the read
    () system call when multiplexing
  libperf tests: Fix verbose printing
  libperf tests: Add test_stat_multiplexing test

 tools/lib/perf/evsel.c                  |   4 +
 tools/lib/perf/include/internal/tests.h |   2 +
 tools/lib/perf/tests/test-evlist.c      | 138 ++++++++++++++++++++++++
 3 files changed, 144 insertions(+)

-- 
2.25.1

```