RISC-V Design · All levels
Page Fault Handling, Trap Flow, and Recovery Paths: Theory Deep Dive
Theory Deep Dive for Page Fault Handling, Trap Flow, and Recovery Paths.
Theory deep dive
Theory Deep Dive for Page Fault Handling, Trap Flow, and Recovery Paths is anchored on Fault service latency (median/P99), restart success rate, and throughput impact during demand paging and copy-on-write stress.. Convert observations into mechanism-backed decisions with explicit ownership.
Theory matters when it predicts engineering outcomes. Tie abstract ISA and microarchitecture concepts to measurable behavior in trace and counter data.
Pipeline model
diagram
RISC-V PIPELINE DIAGRAM - Page Fault Handling, Trap Flow, and Recovery Paths
PC -> IF -> ID -> EX -> MEM -> WB
| | | | |
i-cache decode ALU/BR LSU regfile write
\ |
+-> branch resolve + redirect
Hot paths:
- branch + load-use dependencies in ID/EX
- memory latency stretching MEM stage
- writeback arbitration for integer/vector units
Focus: keep control hazards predictablePrivilege model
diagram
PRIVILEGE MODE STACK - Page Fault Handling, Trap Flow, and Recovery Paths
+------------------------------+
| Machine mode (M) |
| firmware, PMP, trap root |
+---------------+--------------+
|
delegated traps
v
+------------------------------+
| Supervisor mode (S) |
| kernel, page tables, drivers |
+---------------+--------------+
|
ecall / syscall
v
+------------------------------+
| User mode (U) |
| applications, libraries |
+------------------------------+
Key rule: each upward transition records cause + PC in trap CSRs.