]>
Commit | Line | Data |
---|---|---|
5bcae85e SL |
1 | //===-- cache_frag.cpp ----------------------------------------------------===// |
2 | // | |
3 | // The LLVM Compiler Infrastructure | |
4 | // | |
5 | // This file is distributed under the University of Illinois Open Source | |
6 | // License. See LICENSE.TXT for details. | |
7 | // | |
8 | //===----------------------------------------------------------------------===// | |
9 | // | |
10 | // This file is a part of EfficiencySanitizer, a family of performance tuners. | |
11 | // | |
12 | // This file contains cache fragmentation-specific code. | |
13 | //===----------------------------------------------------------------------===// | |
14 | ||
15 | #include "esan.h" | |
16 | #include "esan_flags.h" | |
17 | #include "sanitizer_common/sanitizer_addrhashmap.h" | |
18 | #include "sanitizer_common/sanitizer_common.h" | |
19 | #include "sanitizer_common/sanitizer_placement_new.h" | |
20 | #include <string.h> | |
21 | ||
22 | namespace __esan { | |
23 | ||
24 | //===-- Struct field access counter runtime -------------------------------===// | |
25 | ||
26 | // This should be kept consistent with LLVM's EfficiencySanitizer StructInfo. | |
27 | struct StructInfo { | |
28 | const char *StructName; | |
29 | u32 Size; | |
30 | u32 NumFields; | |
31 | u32 *FieldOffset; // auxiliary struct field info. | |
32 | u32 *FieldSize; // auxiliary struct field info. | |
33 | const char **FieldTypeName; // auxiliary struct field info. | |
34 | u64 *FieldCounters; | |
35 | u64 *ArrayCounter; | |
36 | bool hasAuxFieldInfo() { return FieldOffset != nullptr; } | |
37 | }; | |
38 | ||
39 | // This should be kept consistent with LLVM's EfficiencySanitizer CacheFragInfo. | |
40 | // The tool-specific information per compilation unit (module). | |
41 | struct CacheFragInfo { | |
42 | const char *UnitName; | |
43 | u32 NumStructs; | |
44 | StructInfo *Structs; | |
45 | }; | |
46 | ||
47 | struct StructCounter { | |
48 | StructInfo *Struct; | |
49 | u64 Count; // The total access count of the struct. | |
50 | u64 Ratio; // Difference ratio for the struct layout access. | |
51 | }; | |
52 | ||
53 | // We use StructHashMap to keep track of an unique copy of StructCounter. | |
54 | typedef AddrHashMap<StructCounter, 31051> StructHashMap; | |
55 | struct Context { | |
56 | StructHashMap StructMap; | |
57 | u32 NumStructs; | |
58 | u64 TotalCount; // The total access count of all structs. | |
59 | }; | |
60 | static Context *Ctx; | |
61 | ||
62 | static void reportStructSummary() { | |
63 | // FIXME: provide a better struct field access summary report. | |
64 | Report("%s: total struct field access count = %llu\n", SanitizerToolName, | |
65 | Ctx->TotalCount); | |
66 | } | |
67 | ||
68 | // FIXME: we are still exploring proper ways to evaluate the difference between | |
69 | // struct field counts. Currently, we use a simple formula to calculate the | |
70 | // difference ratio: V1/V2. | |
71 | static inline u64 computeDifferenceRatio(u64 Val1, u64 Val2) { | |
72 | if (Val2 > Val1) { | |
73 | Swap(Val1, Val2); | |
74 | } | |
75 | if (Val2 == 0) | |
76 | Val2 = 1; | |
77 | return (Val1 / Val2); | |
78 | } | |
79 | ||
80 | static void reportStructCounter(StructHashMap::Handle &Handle) { | |
81 | const u32 TypePrintLimit = 512; | |
82 | const char *type, *start, *end; | |
83 | StructInfo *Struct = Handle->Struct; | |
84 | // Union field address calculation is done via bitcast instead of GEP, | |
85 | // so the count for union is always 0. | |
86 | // We skip the union report to avoid confusion. | |
87 | if (strncmp(Struct->StructName, "union.", 6) == 0) | |
88 | return; | |
89 | // Remove the '.' after class/struct during print. | |
90 | if (strncmp(Struct->StructName, "class.", 6) == 0) { | |
91 | type = "class"; | |
92 | start = &Struct->StructName[6]; | |
93 | } else { | |
94 | type = "struct"; | |
95 | start = &Struct->StructName[7]; | |
96 | } | |
7cac9316 XL |
97 | // Remove the suffixes with '$' during print. |
98 | end = strchr(start, '$'); | |
5bcae85e SL |
99 | CHECK(end != nullptr); |
100 | Report(" %s %.*s\n", type, end - start, start); | |
101 | Report(" size = %u, count = %llu, ratio = %llu, array access = %llu\n", | |
102 | Struct->Size, Handle->Count, Handle->Ratio, *Struct->ArrayCounter); | |
103 | if (Struct->hasAuxFieldInfo()) { | |
104 | for (u32 i = 0; i < Struct->NumFields; ++i) { | |
105 | Report(" #%2u: offset = %u,\t size = %u," | |
106 | "\t count = %llu,\t type = %.*s\n", | |
107 | i, Struct->FieldOffset[i], Struct->FieldSize[i], | |
108 | Struct->FieldCounters[i], TypePrintLimit, Struct->FieldTypeName[i]); | |
109 | } | |
110 | } else { | |
111 | for (u32 i = 0; i < Struct->NumFields; ++i) { | |
112 | Report(" #%2u: count = %llu\n", i, Struct->FieldCounters[i]); | |
113 | } | |
114 | } | |
115 | } | |
116 | ||
117 | static void computeStructRatio(StructHashMap::Handle &Handle) { | |
118 | Handle->Ratio = 0; | |
119 | Handle->Count = Handle->Struct->FieldCounters[0]; | |
120 | for (u32 i = 1; i < Handle->Struct->NumFields; ++i) { | |
121 | Handle->Count += Handle->Struct->FieldCounters[i]; | |
122 | Handle->Ratio += computeDifferenceRatio( | |
123 | Handle->Struct->FieldCounters[i - 1], Handle->Struct->FieldCounters[i]); | |
124 | } | |
125 | Ctx->TotalCount += Handle->Count; | |
126 | if (Handle->Ratio >= (u64)getFlags()->report_threshold || | |
127 | (Verbosity() >= 1 && Handle->Count > 0)) | |
128 | reportStructCounter(Handle); | |
129 | } | |
130 | ||
131 | static void registerStructInfo(CacheFragInfo *CacheFrag) { | |
132 | for (u32 i = 0; i < CacheFrag->NumStructs; ++i) { | |
133 | StructInfo *Struct = &CacheFrag->Structs[i]; | |
134 | StructHashMap::Handle H(&Ctx->StructMap, (uptr)Struct->FieldCounters); | |
135 | if (H.created()) { | |
136 | VPrintf(2, " Register %s: %u fields\n", Struct->StructName, | |
137 | Struct->NumFields); | |
138 | H->Struct = Struct; | |
139 | ++Ctx->NumStructs; | |
140 | } else { | |
141 | VPrintf(2, " Duplicated %s: %u fields\n", Struct->StructName, | |
142 | Struct->NumFields); | |
143 | } | |
144 | } | |
145 | } | |
146 | ||
147 | static void unregisterStructInfo(CacheFragInfo *CacheFrag) { | |
148 | // FIXME: if the library is unloaded before finalizeCacheFrag, we should | |
149 | // collect the result for later report. | |
150 | for (u32 i = 0; i < CacheFrag->NumStructs; ++i) { | |
151 | StructInfo *Struct = &CacheFrag->Structs[i]; | |
152 | StructHashMap::Handle H(&Ctx->StructMap, (uptr)Struct->FieldCounters, true); | |
153 | if (H.exists()) { | |
154 | VPrintf(2, " Unregister %s: %u fields\n", Struct->StructName, | |
155 | Struct->NumFields); | |
156 | // FIXME: we should move this call to finalizeCacheFrag once we can | |
157 | // iterate over the hash map there. | |
158 | computeStructRatio(H); | |
159 | --Ctx->NumStructs; | |
160 | } else { | |
161 | VPrintf(2, " Duplicated %s: %u fields\n", Struct->StructName, | |
162 | Struct->NumFields); | |
163 | } | |
164 | } | |
165 | static bool Reported = false; | |
166 | if (Ctx->NumStructs == 0 && !Reported) { | |
167 | Reported = true; | |
168 | reportStructSummary(); | |
169 | } | |
170 | } | |
171 | ||
172 | //===-- Init/exit functions -----------------------------------------------===// | |
173 | ||
174 | void processCacheFragCompilationUnitInit(void *Ptr) { | |
175 | CacheFragInfo *CacheFrag = (CacheFragInfo *)Ptr; | |
176 | VPrintf(2, "in esan::%s: %s with %u class(es)/struct(s)\n", __FUNCTION__, | |
177 | CacheFrag->UnitName, CacheFrag->NumStructs); | |
178 | registerStructInfo(CacheFrag); | |
179 | } | |
180 | ||
181 | void processCacheFragCompilationUnitExit(void *Ptr) { | |
182 | CacheFragInfo *CacheFrag = (CacheFragInfo *)Ptr; | |
183 | VPrintf(2, "in esan::%s: %s with %u class(es)/struct(s)\n", __FUNCTION__, | |
184 | CacheFrag->UnitName, CacheFrag->NumStructs); | |
185 | unregisterStructInfo(CacheFrag); | |
186 | } | |
187 | ||
188 | void initializeCacheFrag() { | |
189 | VPrintf(2, "in esan::%s\n", __FUNCTION__); | |
190 | // We use placement new to initialize Ctx before C++ static initializaion. | |
191 | // We make CtxMem 8-byte aligned for atomic operations in AddrHashMap. | |
192 | static u64 CtxMem[sizeof(Context) / sizeof(u64) + 1]; | |
193 | Ctx = new (CtxMem) Context(); | |
194 | Ctx->NumStructs = 0; | |
195 | } | |
196 | ||
197 | int finalizeCacheFrag() { | |
198 | VPrintf(2, "in esan::%s\n", __FUNCTION__); | |
199 | return 0; | |
200 | } | |
201 | ||
202 | void reportCacheFrag() { | |
203 | VPrintf(2, "in esan::%s\n", __FUNCTION__); | |
204 | // FIXME: Not yet implemented. We need to iterate over all of the | |
205 | // compilation unit data. | |
206 | } | |
207 | ||
208 | } // namespace __esan |