NVME-SNDK-SET-LAT(1) NVMe Manual NVME-SNDK-SET-LAT(1)

nvme-sndk-set-latency-monitor-feature - Set NVMe sndk latency monitor feature options

nvme sndk set-latency-monitor-feature <device>
                        [--active_bucket_timer_threshold=<NUM> | -t <NUM>]
                        [--active_threshold_a=<NUM> | -a <NUM>]
                        [--active_threshold_b=<NUM> | -b <NUM>]
                        [--active_threshold_c=<NUM> | -c <NUM>]
                        [--active_threshold_d=<NUM> | -d <NUM>]
                        [--active_latency_config=<NUM> | -f <NUM>]
                        [--active_latency_minimum_window=<NUM> | -w <NUM>]
                        [--debug_log_trigger_enable=<NUM> | -r <NUM>]
                        [--discard_debug_log=<NUM> | -l <NUM>]
                        [--latency_monitor_feature_enable=<NUM> | -e <NUM>]

For the NVMe device given, this command set the latency monitor feature options (if supported by the device).

The <device> parameter is mandatory NVMe character device (ex: /dev/nvme0).

Setting results can be checked with get-latency-monitor-log command.

On success it returns 0, error code otherwise.

-t <NUM>, --active_bucket_timer_threshold=<NUM>

The value that loads the Active Bucket Timer Threshold; default value is 07E0h.

-a <NUM>, --active_threshold_a=<NUM>

The value that loads into the Active Threshold A; default value is 05h.

-b <NUM>, --active_threshold_b=<NUM>

The value that loads into the Active Threshold B; default value is 13h.

-c <NUM>, --active_threshold_c=<NUM>

The value that loads into the Active Threshold C; default value is 1Eh.

-d <NUM>, --active_threshold_d=<NUM>

The value that loads into the Active Threshold D; default value is 2Eh.

-f <NUM>, --active_latency_config=<NUM>

The value that loads into the Active Latency Configuration. This configures how both the Active Latency Stamp, and the Active Measured Latency Fields are updated on a per I/O command (Read, Write, Deallocate) counter basis; default value is 0FFFh.

-w <NUM>, --active_latency_minimum_window=<NUM>

The value that loads into the Active Latency Minimum Window; default value is 0Ah.

-r <NUM>, --debug_log_trigger_enable=<NUM>

The value that loads into the Debug Log Trigger Enable; When set to 1b the first time the bucket/counter combination is incremented a debug log is triggered. When cleared to 0b a debug log will not be triggered when the bucket/counter combination is incremented.

-l <NUM>, --discard_debug_log=<NUM>

Discard Debug Log. When cleared to 00h the debug log, if it exists, will not be cleared. When set to 01h the debug log will be discarded so another log can be triggered. All the fields in the Set Features Data structure are valid. When set to 02h the debug log will be discarded so another log can be triggered. None of the other fields of the Set Features Data structure are valid.

-e <NUM>, --latency_monitor_feature_enable=<NUM>

Latency Monitor Feature Enable; When set to 01h the Latency Monitor Feature is enabled. When cleared to 00h the Latency Monitor Feature is disabled.

•Set NVMe sndk latency monitor feature options enabled with default value values: 
# nvme sndk set-latency-monitor-feature /dev/nvme0 -e 1
•Set NVMe sndk latency monitor feature options disabled with default value values: 
# nvme sndk set-latency-monitor-feature /dev/nvme0 -e 0
•Set NVMe sndk latency monitor feature options enabled with specific values: 
# nvme sndk set-latency-monitor-feature /dev/nvme0 --active_bucket_timer_threshold=1 \
            --active_threshold_a=0x0 \
            --active_threshold_b=0x1 \
            --active_threshold_c=0x2 \
            --active_threshold_d=0x3 \
            --active_latency_config=0xfff \
            --active_latency_minimum_window=0 \
            --debug_log_trigger_enable=0 \
            --discard_debug_log=0 \
            --latency_monitor_feature_enable=0x1

Part of the nvme-user suite.

05/01/2025 NVMe