Over the last several months, AMD published Instruction Based Sampling extensions, or IBS, for the company's upcoming Zen 4 processor series, reports Michael Larabel of Phoronix. Now that Linux 5.19 is complete, the company has begun to switch focus to the Linux 6.0 kernel for upkeep with the following kernel series.
AMD Zen4 Instruction Based Sampling to have Linux 6.0 perf tooling activation ready upon release on the release of the company's new processor
Published on Thursday, AMD placed the updates to the perf tools into the Linux 6.0 merge window request. Michael Larabel notes the Instruction Based Sampling updates in his recent report and also discusses the features of the DataSrc extensions that were in the newest request:
With the DataSrc extensions, the source of data can be decoded among:
- Local L3 or other L1/L2 in CCX.
- A peer cache in a near CCX.
- Data returned from DRAM.
- A peer cache in a far CCX.
- DRAM address map with "long latency" bit set.
- Data returned from MMIO/Config/PCI/APIC.
- Extension Memory (S-Link, GenZ, etc. - identified by the CS target and/or address map at DF's choice).
- Peer Agent Memory.
Arnaldo Carvalho de Melo, one of the engineers working on the upcoming kernel for AMD, requested Linus. Included in the new perf tools for Linux 6.0 and AMD Zen 4 IBS are updates such as a brand new "perf lock contention sub tool, perf work tool, support hardware tracing utilizing PT on guest VMs, Intel Meteor Lake JSON file for per events, numerous hybrid system enhancements, and other further updates. The "perf work" tool allows tracing the kernel work time properties.
Frequent readers of Phoronix and our site will remember that AMD and Intel have been hard at work prepping Linux 5.19 before its release and have recently readied Linux 6.0 (formerly known as Linux 5.20). AMD Zen 4 is rumored to launch next month on September 15, 2022, which was the reported time by MSI. The release will coincide with the release of their motherboards and AMD's rumored date for Zen4 architecture. AMD's open source engineering department is still working on last-minute code for the company's audio driver along with the IBS preparations.