83bb8624f6
Summary - Fix SEGV root cause in Tiny random_mixed: TINY_REMOTE_SENTINEL leaked from Remote queue into freelist/TLS SLL. - Clear/guard sentinel at the single boundary where Remote merges to freelist. - Add minimal defense-in-depth in freelist_pop and TLS SLL pop. - Silence verbose prints behind debug gates to reduce noise in release runs. - Pool TLS: integrate Remote Queue drain at refill boundary to avoid unnecessary backend carve/OS calls when possible. - DX: strengthen build.sh with help/list/verify and add docs/BUILDING_QUICKSTART.md. Details - core/superslab/superslab_inline.h: guard head/node against TINY_REMOTE_SENTINEL; sanitize node[0] when splicing local chain; only print diagnostics when debug guard is enabled. - core/slab_handle.h: freelist_pop breaks on sentinel head (fail-fast under strict). - core/tiny_alloc_fast_inline.h: TLS SLL pop breaks on sentinel head (rare branch). - core/tiny_superslab_free.inc.h: sentinel scan log behind debug guard. - core/pool_refill.c: try pool_remote_pop_chain() before backend carve in pool_refill_and_alloc(). - core/tiny_adaptive_sizing.c: default adaptive logs off; enable via HAKMEM_ADAPTIVE_LOG=1. - build.sh: add help/list/verify; EXTRA_MAKEFLAGS passthrough; echo pinned flags. - docs/BUILDING_QUICKSTART.md: add one‑pager for targets/flags/env/perf/strace. Verification (high level) - Tiny random_mixed 10k 256/1024: SEGV resolved; runs complete. - Pool TLS 1T/4T perf: HAKMEM >= system (≈ +0.7% 1T, ≈ +2.9% 4T); syscall counts ~10–13. Known issues (to address next) - Tiny random_mixed perf is weak vs system: - 1T/500k/256: cycles/op ≈ 240 vs ~47 (≈5× slower), IPC ≈0.92, branch‑miss ≈11%. - 1T/500k/1024: cycles/op ≈ 149 vs ~53 (≈2.8× slower), IPC ≈0.82, branch‑miss ≈10.5%. - Hypothesis: frequent SuperSlab path for class7 (fast_cap=0), branchy refill/adopt, and hot-path divergence. - Proposed next steps: - Introduce fast_cap>0 for class7 (bounded TLS SLL) and a simpler batch refill. - Add env‑gated Remote Side OFF for 1T A/B (reduce side-table and guards). - Revisit likely/unlikely and unify adopt boundary sequencing (drain→bind→acquire) for Tiny.
32 lines
1.1 KiB
Markdown
32 lines
1.1 KiB
Markdown
# BUILDING Quickstart
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One‑liner (recommended)
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- `./build.sh <target>`
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- Pins: `POOL_TLS_PHASE1=1 HEADER_CLASSIDX=1 AGGRESSIVE_INLINE=1 PREWARM_TLS=1 POOL_TLS_PREWARM=1`
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- Help/targets: `./build.sh help`, `./build.sh list`
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- Verify freshness: `./build.sh verify <binary>`
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Common targets
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- `bench_random_mixed_hakmem` (Tiny 1T mixed)
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- `bench_pool_tls_hakmem` (Pool TLS 8–52KB)
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- `bench_mid_large_mt_hakmem` (Mid‑Large MT 8–32KB)
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- `larson_hakmem` (Larson)
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- System baselines: `bench_*_system`
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Pool TLS Arena ENV (A/B)
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- `export HAKMEM_POOL_TLS_ARENA_MB_INIT=2` # default 1
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- `export HAKMEM_POOL_TLS_ARENA_MB_MAX=16` # default 8
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- `export HAKMEM_POOL_TLS_ARENA_GROWTH_LEVELS=4` # default 3
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Runtime safety/verbosity (optional)
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- `EXTRA_MAKEFLAGS="HAKMEM_TINY_SAFE_FREE=1" ./build.sh <target>`
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- `EXTRA_MAKEFLAGS="HAKMEM_DEBUG_VERBOSE=1" ./build.sh <target>`
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Perf & strace
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- `perf stat -e cycles,instructions,branches,branch-misses,cache-misses -r 3 -- ./<bin> ...`
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- `strace -e trace=mmap,madvise,munmap -c ./<bin> ...`
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Troubleshooting
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- `make print-flags` to inspect flags
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- `./verify_build.sh <bin>` to check binary freshness
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