diff options
Diffstat (limited to 'Documentation/admin-guide/perf/imx-ddr.rst')
| -rw-r--r-- | Documentation/admin-guide/perf/imx-ddr.rst | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/Documentation/admin-guide/perf/imx-ddr.rst b/Documentation/admin-guide/perf/imx-ddr.rst index 517a205abad6..90056e4e8859 100644 --- a/Documentation/admin-guide/perf/imx-ddr.rst +++ b/Documentation/admin-guide/perf/imx-ddr.rst @@ -17,7 +17,8 @@ The "format" directory describes format of the config (event ID) and config1 (AXI filtering) fields of the perf_event_attr structure, see /sys/bus/event_source/ devices/imx8_ddr0/format/. The "events" directory describes the events types hardware supported that can be used with perf tool, see /sys/bus/event_source/ -devices/imx8_ddr0/events/. +devices/imx8_ddr0/events/. The "caps" directory describes filter features implemented +in DDR PMU, see /sys/bus/events_source/devices/imx8_ddr0/caps/. e.g.:: perf stat -a -e imx8_ddr0/cycles/ cmd perf stat -a -e imx8_ddr0/read/,imx8_ddr0/write/ cmd @@ -25,9 +26,12 @@ devices/imx8_ddr0/events/. AXI filtering is only used by CSV modes 0x41 (axid-read) and 0x42 (axid-write) to count reading or writing matches filter setting. Filter setting is various from different DRAM controller implementations, which is distinguished by quirks -in the driver. +in the driver. You also can dump info from userspace, filter in "caps" directory +indicates whether PMU supports AXI ID filter or not; enhanced_filter indicates +whether PMU supports enhanced AXI ID filter or not. Value 0 for un-supported, and +value 1 for supported. -* With DDR_CAP_AXI_ID_FILTER quirk. +* With DDR_CAP_AXI_ID_FILTER quirk(filter: 1, enhanced_filter: 0). Filter is defined with two configuration parts: --AXI_ID defines AxID matching value. --AXI_MASKING defines which bits of AxID are meaningful for the matching. @@ -50,3 +54,8 @@ in the driver. axi_id to monitor a specific id, rather than having to specify axi_mask. e.g.:: perf stat -a -e imx8_ddr0/axid-read,axi_id=0x12/ cmd, which will monitor ARID=0x12 + +* With DDR_CAP_AXI_ID_FILTER_ENHANCED quirk(filter: 1, enhanced_filter: 1). + This is an extension to the DDR_CAP_AXI_ID_FILTER quirk which permits + counting the number of bytes (as opposed to the number of bursts) from DDR + read and write transactions concurrently with another set of data counters. |