[Crash-utility] Re: [PATCH 0/2] RISCV64: optimize symbol handling for large kernel symbol tables

This patch series optimizes symbol handling in crash utility for RISCV64 architecture, particularly beneficial when debugging kernels with large symbol tables (900K+ symbols). Background: On a 32-core RISCV64 physical machine running Linux 6.12.13, the kernel symbol table contains over 900,000 entries (wc -l /proc/kallsyms). When using crash utility to analyze vmcore or live system, significant time is spent in symbol-related operations, specifically: 1. Symbol name hash lookups - the original simple hash function causes high collision rates with large symbol tables 2. Processing of linker-generated mapping symbols (.L*, L0*, $*) which are unnecessary for debugging but consume processing time Patch 1: Optimize symname_hash with larger table and FNV-1a hash - Increases SYMNAME_HASH from 512 to 16384 (32x) to reduce collisions - Replaces simple hash with FNV-1a algorithm for better distribution - Removes strlen() call by computing hash in single pass This reduces average hash bucket chain length significantly, improving symbol lookup performance at the cost of ~248KB additional memory. Patch 2: Add mapping symbol filter in riscv64_verify_symbol - Filters out linker mapping symbols (.L*, L0*, $*) that should not be in the symbol list - Also optimizes riscv64_verify_symbol() by consolidating name validity checks Together these patches improve crash utility startup and symbol lookup performance on RISCV64 systems with large kernel symbol tables. Rui Qi (2): symbols: optimize symname_hash with larger table and FNV-1a hash RISCV64: add mapping symbol filter in riscv64_verify_symbol defs.h | 2 +- riscv64.c | 14 +++++++++++--- symbols.c | 20 ++++++++++++++------ 3 files changed, 27 insertions(+), 9 deletions(-) -- 2.43.0 -- Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki