RISC-V Design · All levels
Performance Tuning and Signoff: Expanded Case Study
Expanded Case Study for Performance Tuning and Signoff.
Expanded case study
Expanded Case Study for Performance Tuning and Signoff is anchored on P95 and P99 workload latency, sustained throughput per subsystem, and power-performance target closure against signoff criteria.. Convert observations into mechanism-backed decisions with explicit ownership.
Use this page to rehearse complete review flow: symptom intake, mechanism split, evidence request, owner assignment, bounded fix, and closure decision.
Root-cause tree
diagram
ROOT CAUSE TREE - Performance Tuning and Signoff
P95 and P99 workload latency, sustained throughput per subsystem, and power-performance target closure against signoff criteria. regressed
|
reproducible on fixed seed?
/ \
no yes
| |
env/tool drift first failing domain?
/ | \
decode execute memory/MMU
| | |
control map bypass/FU TLB/walk/perm
|
privilege/CSR side effects checked?
Stop at first confirmed mechanism, then assign explicit owner + fix proof.Evidence matrix
diagram
RISC-V EVIDENCE MATRIX - Performance Tuning and Signoff
+--------------------------+--------------------------------+--------------------------------+---------------------------+
| Evidence | Tells you | Does not prove | Next action |
+--------------------------+--------------------------------+--------------------------------+---------------------------+
| perf counter timeline | where regression appears | exact mechanism causality | correlate with trace |
| decode/control dump | control intent per instruction | pipeline side-effect ordering | inspect retire semantics |
| trap + CSR logs | privilege/fault behavior | performance bottleneck alone | pair with CPI buckets |
| MMU/TLB walk trace | translation behavior | full system QoS impact | test mixed workloads |
| post-fix trend graph | movement after fix | long-term stability | run stress matrix |
+--------------------------+--------------------------------+--------------------------------+---------------------------+