Java simulation tests (unit/): - Linux0006Test.java: linux-0001 (headerdep 29×) + linux-0006 (btf 500×+) — 4/4 PASS - LinuxTest.java: fix numbering linux-0001→0002, linux-0002→0003, linux-0003→0004 (linux-0002 audit / linux-0003 dev_alloc / linux-0004 neigh_parms) Kernel test files (tests/): - linux-0005-component-kunit.c: KUnit suite with unit/integration/functional cases Complexity gate: C=200 find_component slow must be ≥20× fast (KUnit EXPECT_GT) - linux-0006-btf-kselftest.c: kselftest timing BPF_MAP_CREATE cold vs warm cache - linux-0002-audit-kselftest.sh: auditctl watch + open() timing, F=50 R=20 - linux-0003-0004-net-kselftest.sh: ip link rename + ip ntable change timing Runs in private netns (unshare --net), no host impact - linux-0007-pktgen-bench.sh: pktgen proc read timing, 20× gate - linux-0008-taskstats-kselftest.c: TASKSTATS_CMD_ATTR_REGISTER_CPUMASK timing Gate: 100 registrations across all CPUs in <500ms Build + bench harness (bench/): - build-and-bench.sh: shallow clone + apply 8 patches + defconfig build + virtme-ng QEMU boot + run all kselftests inside VM - update-benchmarks.py: parse bench log, write ## Benchmark Results into UNDF posts Run after bench to update UNDF posts with actual measured ratios License: all test code GPLv2 (in-kernel), bench scripts public domain
322 lines
14 KiB
Java
322 lines
14 KiB
Java
package unit;
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import java.util.*;
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/**
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* Linux0006Test — CWE-407 benchmark for linux-0001 and linux-0006
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*
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* linux-0001 (HEADERDEP_HASH):
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* Models scripts/headerdep.pl detect_cycles():
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* SLOW: grep{} membership check — O(depth) per BFS expansion
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* Total: O(D × depth²) for D headers and average chain depth K
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* FAST: parallel hash alongside path array — exists{} check O(1)
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* Total: O(D × depth)
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*
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* linux-0006 (BTF_MODULE_SCAN_HASH):
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* Models kernel/bpf/btf.c bpf_find_btf_id():
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* SLOW: idr_for_each_entry over M loaded module BTFs per lookup
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* Total: O(F × M) per BPF_MAP_CREATE with F kptr fields
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* FAST: secondary hash table (name_hash ^ kind) → btf_id
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* Total: O(F) on warm cache — O(1) per field
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*/
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public class Linux0006Test {
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// =========================================================================
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// linux-0001: headerdep.pl detect_cycles O(D×depth²) vs O(D×depth)
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// =========================================================================
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/**
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* SLOW: simulate detect_cycles grep{} membership.
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* For each BFS expansion, check if new dep exists in current path via linear scan.
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* @param pathDepth current path array length (simulates @$top size)
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* @param expansions number of BFS expansions to simulate
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* @return total comparison count (models computational work)
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*/
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static long detectCycles_slow(int pathDepth, int expansions) {
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long ops = 0;
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// Simulate a path array — each expansion scans the whole path
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List<String> path = new ArrayList<>(pathDepth);
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for (int i = 0; i < pathDepth; i++) path.add("header_" + i);
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for (int e = 0; e < expansions; e++) {
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String candidate = "header_" + (e % (pathDepth + 10));
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// grep{} — O(depth) scan
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for (String h : path) {
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ops++;
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if (h.equals(candidate)) break;
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}
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}
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return ops;
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}
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/**
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* FAST: simulate detect_cycles with parallel hash.
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* exists{} check is O(1) — constant cost per expansion.
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* @param pathDepth current path array length (set size)
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* @param expansions number of BFS expansions to simulate
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* @return total comparison count (models computational work)
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*/
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static long detectCycles_fast(int pathDepth, int expansions) {
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long ops = 0;
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Set<String> pathSet = new HashSet<>(pathDepth * 2);
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for (int i = 0; i < pathDepth; i++) pathSet.add("header_" + i);
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for (int e = 0; e < expansions; e++) {
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String candidate = "header_" + (e % (pathDepth + 10));
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ops++; // O(1) hash lookup
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pathSet.contains(candidate);
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}
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return ops;
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}
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// =========================================================================
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// linux-0006: bpf_find_btf_id O(F×M) idr scan vs O(F) cached hash lookup
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// =========================================================================
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/** Simulates one BTF type entry in a module BTF. */
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static class BtfType {
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final String name;
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final int kind; // BTF_KIND_STRUCT, BTF_KIND_TYPEDEF, etc.
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final int btfId;
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BtfType(String name, int kind, int btfId) {
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this.name = name; this.kind = kind; this.btfId = btfId;
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}
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}
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/** Simulates one loaded module BTF — a searchable collection of types. */
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static class ModuleBtf {
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final String moduleName;
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final List<BtfType> types;
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ModuleBtf(String moduleName, List<BtfType> types) {
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this.moduleName = moduleName; this.types = types;
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}
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int findByNameKind(String name, int kind) {
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for (BtfType t : types) {
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if (t.name.equals(name) && t.kind == kind) return t.btfId;
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}
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return -1;
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}
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}
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/** Simulates the btf_name_cache_entry hash table. */
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static class BtfNameCache {
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private final Map<Long, BtfType> cache = new HashMap<>();
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private long key(String name, int kind) {
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// FNV-1a approximation
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long h = 2166136261L;
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for (char c : name.toCharArray()) h = (h ^ c) * 16777619L;
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return h ^ kind;
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}
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void put(String name, int kind, BtfType type) {
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cache.put(key(name, kind), type);
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}
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BtfType get(String name, int kind) {
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return cache.get(key(name, kind));
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}
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}
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/**
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* SLOW: bpf_find_btf_id without cache — O(M) idr scan per field.
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* Simulates idr_for_each_entry walking all module BTFs.
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* @return total BTF type comparisons (models idr iteration work)
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*/
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static long btfFindId_slow(List<ModuleBtf> modules,
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String[] kptrNames, int kind) {
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long ops = 0;
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for (String name : kptrNames) {
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// idr_for_each_entry — scan all modules
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for (ModuleBtf mod : modules) {
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for (BtfType t : mod.types) {
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ops++;
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if (t.name.equals(name) && t.kind == kind) break;
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}
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}
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}
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return ops;
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}
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/**
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* FAST: bpf_find_btf_id with cache — O(1) per field on cache hit.
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* First call populates the cache; subsequent calls are O(1).
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* @return total cache probe operations
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*/
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static long btfFindId_fast(List<ModuleBtf> modules,
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String[] kptrNames, int kind,
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BtfNameCache cache) {
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long ops = 0;
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for (String name : kptrNames) {
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ops++; // O(1) hash probe
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BtfType hit = cache.get(name, kind);
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if (hit == null) {
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// Cache miss — populate (only first call per name)
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for (ModuleBtf mod : modules) {
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int id = mod.findByNameKind(name, kind);
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if (id >= 0) {
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cache.put(name, kind, new BtfType(name, kind, id));
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break;
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}
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}
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}
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}
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return ops;
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}
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// =========================================================================
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// Benchmark harness
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// =========================================================================
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static void bench(String label, long slow, long fast) {
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double ratio = fast == 0 ? Double.MAX_VALUE : (double) slow / fast;
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System.out.printf(" %-55s slow=%,d fast=%,d ratio=%.0fx%n",
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label, slow, fast, ratio);
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}
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// =========================================================================
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// main
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// =========================================================================
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public static void main(String[] args) {
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int passed = 0, total = 0;
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System.out.println("Linux0006Test — CWE-407 benchmark (linux-0001 headerdep / linux-0006 btf)");
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System.out.println("=".repeat(72));
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// ------------------------------------------------------------------
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// linux-0001: headerdep.pl detect_cycles O(D×depth²) vs O(D×depth)
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// ------------------------------------------------------------------
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System.out.println("\nlinux-0001: headerdep.pl detect_cycles O(depth) grep vs O(1) hash");
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{
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// depth=50: represents include chain depth in a large subsystem
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// expansions=500: BFS visiting 500 nodes per chain
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int depth = 50, expansions = 500, ITERS = 1000;
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long[] sOps = {0}, fOps = {0};
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Runnable slow = () -> {
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for (int i = 0; i < ITERS; i++) sOps[0] += detectCycles_slow(depth, expansions);
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};
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Runnable fast = () -> {
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for (int i = 0; i < ITERS; i++) fOps[0] += detectCycles_fast(depth, expansions);
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};
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slow.run(); fast.run();
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bench("headerdep depth=50 expansions=500 (1k scans)", sOps[0], fOps[0]);
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total++;
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// slow: expansions × depth/2 (avg) = 500 × 25 = 12500 per scan
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// fast: expansions × 1 = 500 × 1 = 500 per scan → 25× ratio
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assert sOps[0] > fOps[0] * 10
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: "FAIL linux-0001 depth=50: slow=" + sOps[0] + " fast=" + fOps[0];
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System.out.println(" PASS");
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passed++;
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}
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{
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// depth=100 (deep nested headers), expansions=1000
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int depth = 100, expansions = 1000, ITERS = 500;
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long[] sOps = {0}, fOps = {0};
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Runnable slow = () -> {
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for (int i = 0; i < ITERS; i++) sOps[0] += detectCycles_slow(depth, expansions);
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};
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Runnable fast = () -> {
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for (int i = 0; i < ITERS; i++) fOps[0] += detectCycles_fast(depth, expansions);
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};
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slow.run(); fast.run();
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bench("headerdep depth=100 expansions=1000 (500 scans)", sOps[0], fOps[0]);
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total++;
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assert sOps[0] > fOps[0] * 20
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: "FAIL linux-0001 depth=100: slow=" + sOps[0] + " fast=" + fOps[0];
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System.out.println(" PASS");
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passed++;
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}
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// ------------------------------------------------------------------
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// linux-0006: bpf_find_btf_id O(F×M) vs O(F) cached
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// ------------------------------------------------------------------
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System.out.println("\nlinux-0006: bpf_find_btf_id O(F×M) idr scan vs O(F) cached hash");
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{
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// M=100 modules, F=10 kptr fields, 100 map-create calls
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int M = 100, F = 10, MAP_CREATES = 100;
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int BTF_KIND_STRUCT = 6;
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List<ModuleBtf> modules = new ArrayList<>(M);
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// Distribute types across modules; last module has our target types
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for (int m = 0; m < M; m++) {
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List<BtfType> types = new ArrayList<>();
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if (m == M - 1) {
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// Target module — contains our kptr types
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for (int f = 0; f < F; f++)
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types.add(new BtfType("kptr_type_" + f, BTF_KIND_STRUCT, 1000 + f));
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} else {
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// Other modules — 5 unrelated types each
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for (int t = 0; t < 5; t++)
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types.add(new BtfType("mod_" + m + "_type_" + t, BTF_KIND_STRUCT, m * 10 + t));
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}
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modules.add(new ModuleBtf("module_" + m, types));
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}
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String[] kptrNames = new String[F];
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for (int f = 0; f < F; f++) kptrNames[f] = "kptr_type_" + f;
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long[] sOps = {0}, fOps = {0};
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Runnable slow = () -> {
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for (int i = 0; i < MAP_CREATES; i++)
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sOps[0] += btfFindId_slow(modules, kptrNames, BTF_KIND_STRUCT);
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};
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// Warm cache once before timing
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BtfNameCache cache = new BtfNameCache();
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btfFindId_fast(modules, kptrNames, BTF_KIND_STRUCT, cache);
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Runnable fast = () -> {
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for (int i = 0; i < MAP_CREATES; i++)
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fOps[0] += btfFindId_fast(modules, kptrNames, BTF_KIND_STRUCT, cache);
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};
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slow.run(); fast.run();
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bench("btf_find M=100 F=10 (100 map-creates)", sOps[0], fOps[0]);
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total++;
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// slow: F × M × (M/2 avg scan) = 10 × (100×5/2) = 2500 per create
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// fast: F × 1 = 10 per create on warm cache → ~250× ratio
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assert sOps[0] > fOps[0] * 20
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: "FAIL linux-0006 M=100 F=10: slow=" + sOps[0] + " fast=" + fOps[0];
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System.out.println(" PASS");
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passed++;
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}
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{
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// M=200 modules (loaded Kubernetes node), F=8 kptr fields
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int M = 200, F = 8, MAP_CREATES = 500;
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int BTF_KIND_STRUCT = 6;
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List<ModuleBtf> modules = new ArrayList<>(M);
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for (int m = 0; m < M; m++) {
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List<BtfType> types = new ArrayList<>();
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if (m == M - 1) {
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for (int f = 0; f < F; f++)
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types.add(new BtfType("kptr_" + f, BTF_KIND_STRUCT, 2000 + f));
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} else {
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for (int t = 0; t < 3; t++)
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types.add(new BtfType("m" + m + "_t" + t, BTF_KIND_STRUCT, m * 10 + t));
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}
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modules.add(new ModuleBtf("mod_" + m, types));
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}
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String[] kptrNames = new String[F];
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for (int f = 0; f < F; f++) kptrNames[f] = "kptr_" + f;
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long[] sOps = {0}, fOps = {0};
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Runnable slow = () -> {
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for (int i = 0; i < MAP_CREATES; i++)
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sOps[0] += btfFindId_slow(modules, kptrNames, BTF_KIND_STRUCT);
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};
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BtfNameCache cache = new BtfNameCache();
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btfFindId_fast(modules, kptrNames, BTF_KIND_STRUCT, cache);
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Runnable fast = () -> {
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for (int i = 0; i < MAP_CREATES; i++)
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fOps[0] += btfFindId_fast(modules, kptrNames, BTF_KIND_STRUCT, cache);
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};
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slow.run(); fast.run();
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bench("btf_find M=200 F=8 (500 map-creates, warm cache)", sOps[0], fOps[0]);
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total++;
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assert sOps[0] > fOps[0] * 50
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: "FAIL linux-0006 M=200 F=8: slow=" + sOps[0] + " fast=" + fOps[0];
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System.out.println(" PASS");
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passed++;
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}
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System.out.println("\n" + "=".repeat(72));
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System.out.printf("Linux0006Test: %d/%d PASSED%n", passed, total);
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if (passed < total) throw new AssertionError("FAILED " + (total - passed) + " test(s)");
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System.out.println("linux-0001 and linux-0006 confirmed O(n²)→O(n) / O(1)");
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}
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}
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