Documentation/ABI/testing/debugfs-driver-qat_telemetry
Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/debugfs-driver-qat_telemetry
File Facts
- System
- Linux kernel
- Corpus path
Documentation/ABI/testing/debugfs-driver-qat_telemetry- Extension
[no extension]- Size
- 10258 bytes
- Lines
- 260
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: Documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
What: /sys/kernel/debug/qat_<device>_<BDF>/telemetry/control
Date: March 2024
KernelVersion: 6.8
Contact: qat-linux@intel.com
Description: (RW) Enables/disables the reporting of telemetry metrics.
Allowed values to write:
========================
* 0: disable telemetry
* 1: enable telemetry
* 2, 3, 4: enable telemetry and calculate minimum, maximum
and average for each counter over 2, 3 or 4 samples
Returned values:
================
* 1-4: telemetry is enabled and running
* 0: telemetry is disabled
Example.
Writing '3' to this file starts the collection of
telemetry metrics. Samples are collected every second and
stored in a circular buffer of size 3. These values are then
used to calculate the minimum, maximum and average for each
counter. After enabling, counters can be retrieved through
the ``device_data`` file::
echo 3 > /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/control
Writing '0' to this file stops the collection of telemetry
metrics::
echo 0 > /sys/kernel/debug/qat_4xxx_0000:6b:00.0/telemetry/control
This attribute is only available for qat_4xxx and qat_6xxx devices.
What: /sys/kernel/debug/qat_<device>_<BDF>/telemetry/device_data
Date: March 2024
KernelVersion: 6.8
Contact: qat-linux@intel.com
Description: (RO) Reports device telemetry counters.
Reads report metrics about performance and utilization of
a QAT device:
======================= ========================================
Field Description
======================= ========================================
sample_cnt number of acquisitions of telemetry data
from the device. Reads are performed
every 1000 ms.
pci_trans_cnt number of PCIe partial transactions
max_rd_lat maximum logged read latency [ns] (could
be any read operation)
rd_lat_acc_avg average read latency [ns]
max_gp_lat max get to put latency [ns] (only takes
samples for AE0)
gp_lat_acc_avg average get to put latency [ns]
bw_in PCIe, write bandwidth [Mbps]
bw_out PCIe, read bandwidth [Mbps]
re_acc_avg average ring empty time [ns]
at_page_req_lat_avg Address Translator(AT), average page
request latency [ns]
at_trans_lat_avg AT, average page translation latency [ns]
at_max_tlb_used AT, maximum uTLB used
util_cpr<N> utilization of Compression slice N [%]
exec_cpr<N> execution count of Compression slice N
util_xlt<N> utilization of Translator slice N [%]
exec_xlt<N> execution count of Translator slice N
util_dcpr<N> utilization of Decompression slice N [%]
exec_dcpr<N> execution count of Decompression slice N
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.