[PATCH] D107800: [CSSPGO][llvm-profgen] Cut off probe stack from the bottom to reduce memory usage

[Lei Wang via Phabricator via llvm-commits]

wlei created this revision.
Herald added subscribers: hoy, wenlei, lxfind.
wlei requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D107800

Files:
  llvm/tools/llvm-profgen/PerfReader.cpp


Index: llvm/tools/llvm-profgen/PerfReader.cpp
===================================================================
--- llvm/tools/llvm-profgen/PerfReader.cpp
+++ llvm/tools/llvm-profgen/PerfReader.cpp
@@ -18,6 +18,11 @@
                                         cl::ZeroOrMore,
                                         cl::desc("Print unwinder output"));
 
+static cl::opt<int> CSProfProbeStackDepth(
+    "csprof-probe-stack-depth", cl::init(-1), cl::ZeroOrMore,
+    cl::desc("Cut off probe stack from the bottom and keep it up to a given "
+             "depth. No cut is made if the input is -1."));
+
 extern cl::opt<bool> ShowDisassemblyOnly;
 extern cl::opt<bool> ShowSourceLocations;
 
@@ -104,11 +109,18 @@
 std::shared_ptr<ProbeBasedCtxKey> ProbeStack::getContextKey() {
   std::shared_ptr<ProbeBasedCtxKey> ProbeBasedKey =
       std::make_shared<ProbeBasedCtxKey>();
+  auto &P = ProbeBasedKey->Probes;
   for (auto CallProbe : Stack) {
-    ProbeBasedKey->Probes.emplace_back(CallProbe);
+    P.emplace_back(CallProbe);
+  }
+  CSProfileGenerator::compressRecursionContext<const MCDecodedPseudoProbe *>(P);
+  if (CSProfProbeStackDepth >= 0 &&
+      static_cast<size_t>(CSProfProbeStackDepth) < P.size()) {
+    std::copy(P.begin() + P.size() - static_cast<size_t>(CSProfProbeStackDepth),
+              P.end(), P.begin());
+    P.resize(CSProfProbeStackDepth);
   }
-  CSProfileGenerator::compressRecursionContext<const MCDecodedPseudoProbe *>(
-      ProbeBasedKey->Probes);
+
   ProbeBasedKey->genHashCode();
   return ProbeBasedKey;
 }


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D107800.365348.patch
Type: text/x-patch
Size: 1553 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210810/85f33a88/attachment.bin>