From: Junhao He <hejunhao3@huawei.com>
One of the "port" and "bdf" target filter interface must be set, and
the related events should preferably used in the same group.
Update the usage in the documentation.
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
---
.../admin-guide/perf/hisi-pcie-pmu.rst | 31 ++++++++++++++-----
1 file changed, 23 insertions(+), 8 deletions(-)
@@ -37,9 +37,20 @@ Example usage of perf::
hisi_pcie0_core0/rx_mwr_cnt/ [kernel PMU event]
------------------------------------------
- $# perf stat -e hisi_pcie0_core0/rx_mwr_latency/
- $# perf stat -e hisi_pcie0_core0/rx_mwr_cnt/
- $# perf stat -g -e hisi_pcie0_core0/rx_mwr_latency/ -e hisi_pcie0_core0/rx_mwr_cnt/
+ $# perf stat -e hisi_pcie0_core0/rx_mwr_latency,port=0xffff/
+ $# perf stat -e hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/
+
+The related events usually used to calculate the bandwidth, latency or others.
+They need to start and end counting at the same time, therefore related events
+are best used in the same event group to get the expected value. There are two
+ways to know if they are related events:
+a) By event name, such as the latency events "xxx_latency, xxx_cnt" or
+ bandwidth events "xxx_flux, xxx_time".
+b) By event type, such as "event=0xXXXX, event=0x1XXXX".
+
+Example usage of perf group::
+
+ $# perf stat -e "{hisi_pcie0_core0/rx_mwr_latency,port=0xffff/,hisi_pcie0_core0/rx_mwr_cnt,port=0xffff/}"
The current driver does not support sampling. So "perf record" is unsupported.
Also attach to a task is unsupported for PCIe PMU.
@@ -51,8 +62,12 @@ Filter options
PMU could only monitor the performance of traffic downstream target Root
Ports or downstream target Endpoint. PCIe PMU driver support "port" and
- "bdf" interfaces for users, and these two interfaces aren't supported at the
- same time.
+ "bdf" interfaces for users.
+ Please notice that, one of these two interfaces must be set, and can not
+ be supported at the same time. If they are both set, only "port" filter is
+ valid.
+ If "port" filter not being set or is set explicitly to zero (default), the
+ "bdf" filter will be in effect, because "bdf=0" meaning 0000:000:00.0.
- port
@@ -95,7 +110,7 @@ Filter options
Example usage of perf::
- $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,trig_len=0x4,trig_mode=1/ sleep 5
+ $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,trig_len=0x4,trig_mode=1/ sleep 5
3. Threshold filter
@@ -109,7 +124,7 @@ Filter options
Example usage of perf::
- $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,thr_len=0x4,thr_mode=1/ sleep 5
+ $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,thr_len=0x4,thr_mode=1/ sleep 5
4. TLP Length filter
@@ -127,4 +142,4 @@ Filter options
Example usage of perf::
- $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,len_mode=0x1/ sleep 5
+ $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,port=0xffff,len_mode=0x1/ sleep 5