[v4,4/4] docs: perf: Update metric usage for Alibaba's T-Head PMU driver
Commit Message
Alibaba's T-Head ali_drw PMU supports DDR bandwidth metrics. Update
its usage in the documentation.
Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com>
Acked-by: Ian Rogers <irogers@google.com>
---
Documentation/admin-guide/perf/alibaba_pmu.rst | 5 +++++
1 file changed, 5 insertions(+)
Comments
On 20/06/2023 08:12, Jing Zhang wrote:
> Alibaba's T-Head ali_drw PMU supports DDR bandwidth metrics. Update
> its usage in the documentation.
>
> Signed-off-by: Jing Zhang<renyu.zj@linux.alibaba.com>
> Acked-by: Ian Rogers<irogers@google.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
@@ -88,6 +88,11 @@ data bandwidth::
-e ali_drw_27080/hif_rmw/ \
-e ali_drw_27080/cycle/ -- sleep 10
+Example usage of counting all memory read/write bandwidth by metric::
+
+ perf stat -M ddr_read_bandwidth.all -- sleep 10
+ perf stat -M ddr_write_bandwidth.all -- sleep 10
+
The average DRAM bandwidth can be calculated as follows:
- Read Bandwidth = perf_hif_rd * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle