diff mbox series

[RESEND,v2,1/3] docs: perf: Add description for Alibaba's T-Head PMU driver

Message ID 20220715151310.90091-2-xueshuai@linux.alibaba.com (mailing list archive)
State New, archived
Headers show
Series [RESEND,v2,1/3] docs: perf: Add description for Alibaba's T-Head PMU driver | expand

Commit Message

Shuai Xue July 15, 2022, 3:13 p.m. UTC
Alibaba's T-Head SoC implements uncore PMU for performance and functional
debugging to facilitate system maintenance. Document it to provide guidance
on how to use it.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
---
 .../admin-guide/perf/alibaba_pmu.rst          | 100 ++++++++++++++++++
 Documentation/admin-guide/perf/index.rst      |   1 +
 2 files changed, 101 insertions(+)
 create mode 100644 Documentation/admin-guide/perf/alibaba_pmu.rst

Comments

Jonathan Cameron July 19, 2022, 12:35 p.m. UTC | #1
On Fri, 15 Jul 2022 23:13:08 +0800
Shuai Xue <xueshuai@linux.alibaba.com> wrote:

> Alibaba's T-Head SoC implements uncore PMU for performance and functional
> debugging to facilitate system maintenance. Document it to provide guidance
> on how to use it.
> 
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
I'm far from an expert on this, but looks good to me.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  .../admin-guide/perf/alibaba_pmu.rst          | 100 ++++++++++++++++++
>  Documentation/admin-guide/perf/index.rst      |   1 +
>  2 files changed, 101 insertions(+)
>  create mode 100644 Documentation/admin-guide/perf/alibaba_pmu.rst
> 
> diff --git a/Documentation/admin-guide/perf/alibaba_pmu.rst b/Documentation/admin-guide/perf/alibaba_pmu.rst
> new file mode 100644
> index 000000000000..11de998bb480
> --- /dev/null
> +++ b/Documentation/admin-guide/perf/alibaba_pmu.rst
> @@ -0,0 +1,100 @@
> +=============================================================
> +Alibaba's T-Head SoC Uncore Performance Monitoring Unit (PMU)
> +=============================================================
> +
> +The Yitian 710, custom-built by Alibaba Group's chip development business,
> +T-Head, implements uncore PMU for performance and functional debugging to
> +facilitate system maintenance.
> +
> +DDR Sub-System Driveway (DRW) PMU Driver
> +=========================================
> +
> +Yitian 710 employs eight DDR5/4 channels, four on each die. Each DDR5 channel
> +is independent of others to service system memory requests. And one DDR5
> +channel is split into two independent sub-channels. The DDR Sub-System Driveway
> +implements separate PMUs for each sub-channel to monitor various performance
> +metrics.
> +
> +The Driveway PMU devices are named as ali_drw_<sys_base_addr> with perf.
> +For example, ali_drw_21000 and ali_drw_21080 are two PMU devices for two
> +sub-channels of the same channel in die 0. And the PMU device of die 1 is
> +prefixed with ali_drw_400XXXXX, e.g. ali_drw_40021000.
> +
> +Each sub-channel has 36 PMU counters in total, which is classified into
> +four groups:
> +
> +- Group 0: PMU Cycle Counter. This group has one pair of counters
> +  pmu_cycle_cnt_low and pmu_cycle_cnt_high, that is used as the cycle count
> +  based on DDRC core clock.
> +
> +- Group 1: PMU Bandwidth Counters. This group has 8 counters that are used
> +  to count the total access number of either the eight bank groups in a
> +  selected rank, or four ranks separately in the first 4 counters. The base
> +  transfer unit is 64B.
> +
> +- Group 2: PMU Retry Counters. This group has 10 counters, that intend to
> +  count the total retry number of each type of uncorrectable error.
> +
> +- Group 3: PMU Common Counters. This group has 16 counters, that are used
> +  to count the common events.
> +
> +For now, the Driveway PMU driver only uses counters in group 0 and group 3.
> +
> +The DDR Controller (DDRCTL) and DDR PHY combine to create a complete solution
> +for connecting an SoC application bus to DDR memory devices. The DDRCTL
> +receives transactions Host Interface (HIF) which is custom-defined by Synopsys.
> +These transactions are queued internally and scheduled for access while
> +satisfying the SDRAM protocol timing requirements, transaction priorities, and
> +dependencies between the transactions. The DDRCTL in turn issues commands on
> +the DDR PHY Interface (DFI) to the PHY module, which launches and captures data
> +to and from the SDRAM. The driveway PMUs have hardware logic to gather
> +statistics and performance logging signals on HIF, DFI, etc.
> +
> +By counting the READ, WRITE and RMW commands sent to the DDRC through the HIF
> +interface, we could calculate the bandwidth. Example usage of counting memory
> +data bandwidth::
> +
> +  perf stat \
> +    -e ali_drw_21000/hif_wr/ \
> +    -e ali_drw_21000/hif_rd/ \
> +    -e ali_drw_21000/hif_rmw/ \
> +    -e ali_drw_21000/cycle/ \
> +    -e ali_drw_21080/hif_wr/ \
> +    -e ali_drw_21080/hif_rd/ \
> +    -e ali_drw_21080/hif_rmw/ \
> +    -e ali_drw_21080/cycle/ \
> +    -e ali_drw_23000/hif_wr/ \
> +    -e ali_drw_23000/hif_rd/ \
> +    -e ali_drw_23000/hif_rmw/ \
> +    -e ali_drw_23000/cycle/ \
> +    -e ali_drw_23080/hif_wr/ \
> +    -e ali_drw_23080/hif_rd/ \
> +    -e ali_drw_23080/hif_rmw/ \
> +    -e ali_drw_23080/cycle/ \
> +    -e ali_drw_25000/hif_wr/ \
> +    -e ali_drw_25000/hif_rd/ \
> +    -e ali_drw_25000/hif_rmw/ \
> +    -e ali_drw_25000/cycle/ \
> +    -e ali_drw_25080/hif_wr/ \
> +    -e ali_drw_25080/hif_rd/ \
> +    -e ali_drw_25080/hif_rmw/ \
> +    -e ali_drw_25080/cycle/ \
> +    -e ali_drw_27000/hif_wr/ \
> +    -e ali_drw_27000/hif_rd/ \
> +    -e ali_drw_27000/hif_rmw/ \
> +    -e ali_drw_27000/cycle/ \
> +    -e ali_drw_27080/hif_wr/ \
> +    -e ali_drw_27080/hif_rd/ \
> +    -e ali_drw_27080/hif_rmw/ \
> +    -e ali_drw_27080/cycle/ -- sleep 10
> +
> +The average DRAM bandwidth can be calculated as follows:
> +
> +- Read Bandwidth =  perf_hif_rd * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
> +- Write Bandwidth = (perf_hif_wr + perf_hif_rmw) * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
> +
> +Here, DDRC_WIDTH = 64 bytes.
> +
> +The current driver does not support sampling. So "perf record" is
> +unsupported.  Also attach to a task is unsupported as the events are all
> +uncore.
> diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
> index 69b23f087c05..823db08863db 100644
> --- a/Documentation/admin-guide/perf/index.rst
> +++ b/Documentation/admin-guide/perf/index.rst
> @@ -17,3 +17,4 @@ Performance monitor support
>     xgene-pmu
>     arm_dsu_pmu
>     thunderx2-pmu
> +   alibaba_pmu
Shuai Xue July 20, 2022, 1:41 a.m. UTC | #2
在 2022/7/19 PM8:35, Jonathan Cameron 写道:
> On Fri, 15 Jul 2022 23:13:08 +0800
> Shuai Xue <xueshuai@linux.alibaba.com> wrote:
> 
>> Alibaba's T-Head SoC implements uncore PMU for performance and functional
>> debugging to facilitate system maintenance. Document it to provide guidance
>> on how to use it.
>>
>> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
> I'm far from an expert on this, but looks good to me.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Thanks for the review.

Cheers,
Shuai


>> ---
>>  .../admin-guide/perf/alibaba_pmu.rst          | 100 ++++++++++++++++++
>>  Documentation/admin-guide/perf/index.rst      |   1 +
>>  2 files changed, 101 insertions(+)
>>  create mode 100644 Documentation/admin-guide/perf/alibaba_pmu.rst
>>
>> diff --git a/Documentation/admin-guide/perf/alibaba_pmu.rst b/Documentation/admin-guide/perf/alibaba_pmu.rst
>> new file mode 100644
>> index 000000000000..11de998bb480
>> --- /dev/null
>> +++ b/Documentation/admin-guide/perf/alibaba_pmu.rst
>> @@ -0,0 +1,100 @@
>> +=============================================================
>> +Alibaba's T-Head SoC Uncore Performance Monitoring Unit (PMU)
>> +=============================================================
>> +
>> +The Yitian 710, custom-built by Alibaba Group's chip development business,
>> +T-Head, implements uncore PMU for performance and functional debugging to
>> +facilitate system maintenance.
>> +
>> +DDR Sub-System Driveway (DRW) PMU Driver
>> +=========================================
>> +
>> +Yitian 710 employs eight DDR5/4 channels, four on each die. Each DDR5 channel
>> +is independent of others to service system memory requests. And one DDR5
>> +channel is split into two independent sub-channels. The DDR Sub-System Driveway
>> +implements separate PMUs for each sub-channel to monitor various performance
>> +metrics.
>> +
>> +The Driveway PMU devices are named as ali_drw_<sys_base_addr> with perf.
>> +For example, ali_drw_21000 and ali_drw_21080 are two PMU devices for two
>> +sub-channels of the same channel in die 0. And the PMU device of die 1 is
>> +prefixed with ali_drw_400XXXXX, e.g. ali_drw_40021000.
>> +
>> +Each sub-channel has 36 PMU counters in total, which is classified into
>> +four groups:
>> +
>> +- Group 0: PMU Cycle Counter. This group has one pair of counters
>> +  pmu_cycle_cnt_low and pmu_cycle_cnt_high, that is used as the cycle count
>> +  based on DDRC core clock.
>> +
>> +- Group 1: PMU Bandwidth Counters. This group has 8 counters that are used
>> +  to count the total access number of either the eight bank groups in a
>> +  selected rank, or four ranks separately in the first 4 counters. The base
>> +  transfer unit is 64B.
>> +
>> +- Group 2: PMU Retry Counters. This group has 10 counters, that intend to
>> +  count the total retry number of each type of uncorrectable error.
>> +
>> +- Group 3: PMU Common Counters. This group has 16 counters, that are used
>> +  to count the common events.
>> +
>> +For now, the Driveway PMU driver only uses counters in group 0 and group 3.
>> +
>> +The DDR Controller (DDRCTL) and DDR PHY combine to create a complete solution
>> +for connecting an SoC application bus to DDR memory devices. The DDRCTL
>> +receives transactions Host Interface (HIF) which is custom-defined by Synopsys.
>> +These transactions are queued internally and scheduled for access while
>> +satisfying the SDRAM protocol timing requirements, transaction priorities, and
>> +dependencies between the transactions. The DDRCTL in turn issues commands on
>> +the DDR PHY Interface (DFI) to the PHY module, which launches and captures data
>> +to and from the SDRAM. The driveway PMUs have hardware logic to gather
>> +statistics and performance logging signals on HIF, DFI, etc.
>> +
>> +By counting the READ, WRITE and RMW commands sent to the DDRC through the HIF
>> +interface, we could calculate the bandwidth. Example usage of counting memory
>> +data bandwidth::
>> +
>> +  perf stat \
>> +    -e ali_drw_21000/hif_wr/ \
>> +    -e ali_drw_21000/hif_rd/ \
>> +    -e ali_drw_21000/hif_rmw/ \
>> +    -e ali_drw_21000/cycle/ \
>> +    -e ali_drw_21080/hif_wr/ \
>> +    -e ali_drw_21080/hif_rd/ \
>> +    -e ali_drw_21080/hif_rmw/ \
>> +    -e ali_drw_21080/cycle/ \
>> +    -e ali_drw_23000/hif_wr/ \
>> +    -e ali_drw_23000/hif_rd/ \
>> +    -e ali_drw_23000/hif_rmw/ \
>> +    -e ali_drw_23000/cycle/ \
>> +    -e ali_drw_23080/hif_wr/ \
>> +    -e ali_drw_23080/hif_rd/ \
>> +    -e ali_drw_23080/hif_rmw/ \
>> +    -e ali_drw_23080/cycle/ \
>> +    -e ali_drw_25000/hif_wr/ \
>> +    -e ali_drw_25000/hif_rd/ \
>> +    -e ali_drw_25000/hif_rmw/ \
>> +    -e ali_drw_25000/cycle/ \
>> +    -e ali_drw_25080/hif_wr/ \
>> +    -e ali_drw_25080/hif_rd/ \
>> +    -e ali_drw_25080/hif_rmw/ \
>> +    -e ali_drw_25080/cycle/ \
>> +    -e ali_drw_27000/hif_wr/ \
>> +    -e ali_drw_27000/hif_rd/ \
>> +    -e ali_drw_27000/hif_rmw/ \
>> +    -e ali_drw_27000/cycle/ \
>> +    -e ali_drw_27080/hif_wr/ \
>> +    -e ali_drw_27080/hif_rd/ \
>> +    -e ali_drw_27080/hif_rmw/ \
>> +    -e ali_drw_27080/cycle/ -- sleep 10
>> +
>> +The average DRAM bandwidth can be calculated as follows:
>> +
>> +- Read Bandwidth =  perf_hif_rd * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
>> +- Write Bandwidth = (perf_hif_wr + perf_hif_rmw) * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
>> +
>> +Here, DDRC_WIDTH = 64 bytes.
>> +
>> +The current driver does not support sampling. So "perf record" is
>> +unsupported.  Also attach to a task is unsupported as the events are all
>> +uncore.
>> diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
>> index 69b23f087c05..823db08863db 100644
>> --- a/Documentation/admin-guide/perf/index.rst
>> +++ b/Documentation/admin-guide/perf/index.rst
>> @@ -17,3 +17,4 @@ Performance monitor support
>>     xgene-pmu
>>     arm_dsu_pmu
>>     thunderx2-pmu
>> +   alibaba_pmu
diff mbox series

Patch

diff --git a/Documentation/admin-guide/perf/alibaba_pmu.rst b/Documentation/admin-guide/perf/alibaba_pmu.rst
new file mode 100644
index 000000000000..11de998bb480
--- /dev/null
+++ b/Documentation/admin-guide/perf/alibaba_pmu.rst
@@ -0,0 +1,100 @@ 
+=============================================================
+Alibaba's T-Head SoC Uncore Performance Monitoring Unit (PMU)
+=============================================================
+
+The Yitian 710, custom-built by Alibaba Group's chip development business,
+T-Head, implements uncore PMU for performance and functional debugging to
+facilitate system maintenance.
+
+DDR Sub-System Driveway (DRW) PMU Driver
+=========================================
+
+Yitian 710 employs eight DDR5/4 channels, four on each die. Each DDR5 channel
+is independent of others to service system memory requests. And one DDR5
+channel is split into two independent sub-channels. The DDR Sub-System Driveway
+implements separate PMUs for each sub-channel to monitor various performance
+metrics.
+
+The Driveway PMU devices are named as ali_drw_<sys_base_addr> with perf.
+For example, ali_drw_21000 and ali_drw_21080 are two PMU devices for two
+sub-channels of the same channel in die 0. And the PMU device of die 1 is
+prefixed with ali_drw_400XXXXX, e.g. ali_drw_40021000.
+
+Each sub-channel has 36 PMU counters in total, which is classified into
+four groups:
+
+- Group 0: PMU Cycle Counter. This group has one pair of counters
+  pmu_cycle_cnt_low and pmu_cycle_cnt_high, that is used as the cycle count
+  based on DDRC core clock.
+
+- Group 1: PMU Bandwidth Counters. This group has 8 counters that are used
+  to count the total access number of either the eight bank groups in a
+  selected rank, or four ranks separately in the first 4 counters. The base
+  transfer unit is 64B.
+
+- Group 2: PMU Retry Counters. This group has 10 counters, that intend to
+  count the total retry number of each type of uncorrectable error.
+
+- Group 3: PMU Common Counters. This group has 16 counters, that are used
+  to count the common events.
+
+For now, the Driveway PMU driver only uses counters in group 0 and group 3.
+
+The DDR Controller (DDRCTL) and DDR PHY combine to create a complete solution
+for connecting an SoC application bus to DDR memory devices. The DDRCTL
+receives transactions Host Interface (HIF) which is custom-defined by Synopsys.
+These transactions are queued internally and scheduled for access while
+satisfying the SDRAM protocol timing requirements, transaction priorities, and
+dependencies between the transactions. The DDRCTL in turn issues commands on
+the DDR PHY Interface (DFI) to the PHY module, which launches and captures data
+to and from the SDRAM. The driveway PMUs have hardware logic to gather
+statistics and performance logging signals on HIF, DFI, etc.
+
+By counting the READ, WRITE and RMW commands sent to the DDRC through the HIF
+interface, we could calculate the bandwidth. Example usage of counting memory
+data bandwidth::
+
+  perf stat \
+    -e ali_drw_21000/hif_wr/ \
+    -e ali_drw_21000/hif_rd/ \
+    -e ali_drw_21000/hif_rmw/ \
+    -e ali_drw_21000/cycle/ \
+    -e ali_drw_21080/hif_wr/ \
+    -e ali_drw_21080/hif_rd/ \
+    -e ali_drw_21080/hif_rmw/ \
+    -e ali_drw_21080/cycle/ \
+    -e ali_drw_23000/hif_wr/ \
+    -e ali_drw_23000/hif_rd/ \
+    -e ali_drw_23000/hif_rmw/ \
+    -e ali_drw_23000/cycle/ \
+    -e ali_drw_23080/hif_wr/ \
+    -e ali_drw_23080/hif_rd/ \
+    -e ali_drw_23080/hif_rmw/ \
+    -e ali_drw_23080/cycle/ \
+    -e ali_drw_25000/hif_wr/ \
+    -e ali_drw_25000/hif_rd/ \
+    -e ali_drw_25000/hif_rmw/ \
+    -e ali_drw_25000/cycle/ \
+    -e ali_drw_25080/hif_wr/ \
+    -e ali_drw_25080/hif_rd/ \
+    -e ali_drw_25080/hif_rmw/ \
+    -e ali_drw_25080/cycle/ \
+    -e ali_drw_27000/hif_wr/ \
+    -e ali_drw_27000/hif_rd/ \
+    -e ali_drw_27000/hif_rmw/ \
+    -e ali_drw_27000/cycle/ \
+    -e ali_drw_27080/hif_wr/ \
+    -e ali_drw_27080/hif_rd/ \
+    -e ali_drw_27080/hif_rmw/ \
+    -e ali_drw_27080/cycle/ -- sleep 10
+
+The average DRAM bandwidth can be calculated as follows:
+
+- Read Bandwidth =  perf_hif_rd * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
+- Write Bandwidth = (perf_hif_wr + perf_hif_rmw) * DDRC_WIDTH * DDRC_Freq / DDRC_Cycle
+
+Here, DDRC_WIDTH = 64 bytes.
+
+The current driver does not support sampling. So "perf record" is
+unsupported.  Also attach to a task is unsupported as the events are all
+uncore.
diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
index 69b23f087c05..823db08863db 100644
--- a/Documentation/admin-guide/perf/index.rst
+++ b/Documentation/admin-guide/perf/index.rst
@@ -17,3 +17,4 @@  Performance monitor support
    xgene-pmu
    arm_dsu_pmu
    thunderx2-pmu
+   alibaba_pmu