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[MemProf] Add ability to export or highlight only a portion of graph #128255

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merged 1 commit into from
Feb 22, 2025
Merged

[MemProf] Add ability to export or highlight only a portion of graph #128255

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145 changes: 132 additions & 13 deletions llvm/lib/Transforms/IPO/MemProfContextDisambiguation.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -100,6 +100,34 @@ static cl::opt<bool> ExportToDot("memprof-export-to-dot", cl::init(false),
cl::Hidden,
cl::desc("Export graph to dot files."));

// How much of the graph to export to dot.
enum DotScope {
All, // The full CCG graph.
Alloc, // Only contexts for the specified allocation.
Context, // Only the specified context.
};

static cl::opt<DotScope> DotGraphScope(
"memprof-dot-scope", cl::desc("Scope of graph to export to dot"),
cl::Hidden, cl::init(DotScope::All),
cl::values(
clEnumValN(DotScope::All, "all", "Export full callsite graph"),
clEnumValN(DotScope::Alloc, "alloc",
"Export only nodes with contexts feeding given "
"-memprof-dot-alloc-id"),
clEnumValN(DotScope::Context, "context",
"Export only nodes with given -memprof-dot-context-id")));

static cl::opt<unsigned>
AllocIdForDot("memprof-dot-alloc-id", cl::init(0), cl::Hidden,
cl::desc("Id of alloc to export if -memprof-dot-scope=alloc "
"or to highlight if -memprof-dot-scope=all"));

static cl::opt<unsigned> ContextIdForDot(
"memprof-dot-context-id", cl::init(0), cl::Hidden,
cl::desc("Id of context to export if -memprof-dot-scope=context or to "
"highlight otherwise"));

static cl::opt<bool>
DumpCCG("memprof-dump-ccg", cl::init(false), cl::Hidden,
cl::desc("Dump CallingContextGraph to stdout after each stage."));
Expand Down Expand Up @@ -548,6 +576,10 @@ class CallsiteContextGraph {
/// Map from callsite node to the enclosing caller function.
std::map<const ContextNode *, const FuncTy *> NodeToCallingFunc;

// When exporting to dot, and an allocation id is specified, contains the
// context ids on that allocation.
DenseSet<uint32_t> DotAllocContextIds;

private:
using EdgeIter = typename std::vector<std::shared_ptr<ContextEdge>>::iterator;

Expand Down Expand Up @@ -1324,6 +1356,8 @@ CallsiteContextGraph<DerivedCCG, FuncTy, CallTy>::duplicateContextIds(
assert(ContextIdToAllocationType.count(OldId));
// The new context has the same allocation type as original.
ContextIdToAllocationType[LastContextId] = ContextIdToAllocationType[OldId];
if (DotAllocContextIds.contains(OldId))
DotAllocContextIds.insert(LastContextId);
}
return NewContextIds;
}
Expand Down Expand Up @@ -2084,6 +2118,10 @@ ModuleCallsiteContextGraph::ModuleCallsiteContextGraph(
AllocNode, StackContext, CallsiteContext,
getMIBAllocType(MIBMD), ContextSizeInfo);
}
// If exporting the graph to dot and an allocation id of interest was
// specified, record all the context ids for this allocation node.
if (ExportToDot && AllocNode->OrigStackOrAllocId == AllocIdForDot)
DotAllocContextIds = AllocNode->getContextIds();
assert(AllocNode->AllocTypes != (uint8_t)AllocationType::None);
// Memprof and callsite metadata on memory allocations no longer
// needed.
Expand Down Expand Up @@ -2176,6 +2214,10 @@ IndexCallsiteContextGraph::IndexCallsiteContextGraph(
ContextSizeInfo);
I++;
}
// If exporting the graph to dot and an allocation id of interest was
// specified, record all the context ids for this allocation node.
if (ExportToDot && AllocNode->OrigStackOrAllocId == AllocIdForDot)
DotAllocContextIds = AllocNode->getContextIds();
assert(AllocNode->AllocTypes != (uint8_t)AllocationType::None);
// Initialize version 0 on the summary alloc node to the current alloc
// type, unless it has both types in which case make it default, so
Expand Down Expand Up @@ -3021,7 +3063,16 @@ struct GraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *> {
template <typename DerivedCCG, typename FuncTy, typename CallTy>
struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
: public DefaultDOTGraphTraits {
DOTGraphTraits(bool IsSimple = false) : DefaultDOTGraphTraits(IsSimple) {}
DOTGraphTraits(bool IsSimple = false) : DefaultDOTGraphTraits(IsSimple) {
// If the user requested the full graph to be exported, but provided an
// allocation id, or if the user gave a context id and requested more than
// just a specific context to be exported, note that highlighting is
// enabled.
DoHighlight =
(AllocIdForDot.getNumOccurrences() && DotGraphScope == DotScope::All) ||
(ContextIdForDot.getNumOccurrences() &&
DotGraphScope != DotScope::Context);
}

using GraphType = const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *;
using GTraits = GraphTraits<GraphType>;
Expand Down Expand Up @@ -3049,12 +3100,29 @@ struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
return LabelString;
}

static std::string getNodeAttributes(NodeRef Node, GraphType) {
static std::string getNodeAttributes(NodeRef Node, GraphType G) {
auto ContextIds = Node->getContextIds();
// If highlighting enabled, see if this node contains any of the context ids
// of interest. If so, it will use a different color and a larger fontsize
// (which makes the node larger as well).
bool Highlight = false;
if (DoHighlight) {
assert(ContextIdForDot.getNumOccurrences() ||
AllocIdForDot.getNumOccurrences());
if (ContextIdForDot.getNumOccurrences())
Highlight = ContextIds.contains(ContextIdForDot);
else
Highlight = set_intersects(ContextIds, G->DotAllocContextIds);
}
std::string AttributeString = (Twine("tooltip=\"") + getNodeId(Node) + " " +
getContextIds(Node->getContextIds()) + "\"")
getContextIds(ContextIds) + "\"")
.str();
// Default fontsize is 14
if (Highlight)
AttributeString += ",fontsize=\"30\"";
AttributeString +=
(Twine(",fillcolor=\"") + getColor(Node->AllocTypes) + "\"").str();
(Twine(",fillcolor=\"") + getColor(Node->AllocTypes, Highlight) + "\"")
.str();
if (Node->CloneOf) {
AttributeString += ",color=\"blue\"";
AttributeString += ",style=\"filled,bold,dashed\"";
Expand All @@ -3064,9 +3132,22 @@ struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
}

static std::string getEdgeAttributes(NodeRef, ChildIteratorType ChildIter,
GraphType) {
GraphType G) {
auto &Edge = *(ChildIter.getCurrent());
auto Color = getColor(Edge->AllocTypes);
// If highlighting enabled, see if this edge contains any of the context ids
// of interest. If so, it will use a different color and a heavier arrow
// size and weight (the larger weight makes the highlighted path
// straighter).
bool Highlight = false;
if (DoHighlight) {
assert(ContextIdForDot.getNumOccurrences() ||
AllocIdForDot.getNumOccurrences());
if (ContextIdForDot.getNumOccurrences())
Highlight = Edge->ContextIds.contains(ContextIdForDot);
else
Highlight = set_intersects(Edge->ContextIds, G->DotAllocContextIds);
}
auto Color = getColor(Edge->AllocTypes, Highlight);
std::string AttributeString =
(Twine("tooltip=\"") + getContextIds(Edge->ContextIds) + "\"" +
// fillcolor is the arrow head and color is the line
Expand All @@ -3075,13 +3156,24 @@ struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
.str();
if (Edge->IsBackedge)
AttributeString += ",style=\"dotted\"";
// Default penwidth and weight are both 1.
if (Highlight)
AttributeString += ",penwidth=\"2.0\",weight=\"2\"";
return AttributeString;
}

// Since the NodeOwners list includes nodes that are no longer connected to
// the graph, skip them here.
static bool isNodeHidden(NodeRef Node, GraphType) {
return Node->isRemoved();
static bool isNodeHidden(NodeRef Node, GraphType G) {
if (Node->isRemoved())
return true;
// If a scope smaller than the full graph was requested, see if this node
// contains any of the context ids of interest.
if (DotGraphScope == DotScope::Alloc)
return !set_intersects(Node->getContextIds(), G->DotAllocContextIds);
if (DotGraphScope == DotScope::Context)
return !Node->getContextIds().contains(ContextIdForDot);
return false;
}

private:
Expand All @@ -3098,16 +3190,20 @@ struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
return IdString;
}

static std::string getColor(uint8_t AllocTypes) {
static std::string getColor(uint8_t AllocTypes, bool Highlight) {
// If DoHighlight is not enabled, we want to use the highlight colors for
// NotCold and Cold, and the non-highlight color for NotCold+Cold. This is
// both compatible with the color scheme before highlighting was supported,
// and for the NotCold+Cold color the non-highlight color is a bit more
// readable.
if (AllocTypes == (uint8_t)AllocationType::NotCold)
// Color "brown1" actually looks like a lighter red.
return "brown1";
return !DoHighlight || Highlight ? "brown1" : "lightpink";
if (AllocTypes == (uint8_t)AllocationType::Cold)
return "cyan";
return !DoHighlight || Highlight ? "cyan" : "lightskyblue";
if (AllocTypes ==
((uint8_t)AllocationType::NotCold | (uint8_t)AllocationType::Cold))
// Lighter purple.
return "mediumorchid1";
return Highlight ? "magenta" : "mediumorchid1";
return "gray";
}

Expand All @@ -3117,8 +3213,17 @@ struct DOTGraphTraits<const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>
std::string Result = SStream.str();
return Result;
}

// True if we should highlight a specific context or allocation's contexts in
// the emitted graph.
static bool DoHighlight;
};

template <typename DerivedCCG, typename FuncTy, typename CallTy>
bool DOTGraphTraits<
const CallsiteContextGraph<DerivedCCG, FuncTy, CallTy> *>::DoHighlight =
false;

template <typename DerivedCCG, typename FuncTy, typename CallTy>
void CallsiteContextGraph<DerivedCCG, FuncTy, CallTy>::exportToDot(
std::string Label) const {
Expand Down Expand Up @@ -5181,6 +5286,20 @@ bool MemProfContextDisambiguation::processModule(
MemProfContextDisambiguation::MemProfContextDisambiguation(
const ModuleSummaryIndex *Summary, bool isSamplePGO)
: ImportSummary(Summary), isSamplePGO(isSamplePGO) {
// Check the dot graph printing options once here, to make sure we have valid
// and expected combinations.
if (DotGraphScope == DotScope::Alloc && !AllocIdForDot.getNumOccurrences())
llvm::report_fatal_error(
"-memprof-dot-scope=alloc requires -memprof-dot-alloc-id");
if (DotGraphScope == DotScope::Context &&
!ContextIdForDot.getNumOccurrences())
llvm::report_fatal_error(
"-memprof-dot-scope=context requires -memprof-dot-context-id");
if (DotGraphScope == DotScope::All && AllocIdForDot.getNumOccurrences() &&
ContextIdForDot.getNumOccurrences())
llvm::report_fatal_error(
"-memprof-dot-scope=all can't have both -memprof-dot-alloc-id and "
"-memprof-dot-context-id");
if (ImportSummary) {
// The MemProfImportSummary should only be used for testing ThinLTO
// distributed backend handling via opt, in which case we don't have a
Expand Down
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