Enable wider slabs experiment.

When the experiment is enabled, we use wider 512K slabs and double the capacities of size classes in per-cpu cache. PiperOrigin-RevId: 581366463 Change-Id: I7dd1ee8974f81bc5805825a3c52f8776eca0136e
google · Nov 10, 2023 · 6d03c07 · 6d03c07
1 parent e07f7b3
commit 6d03c07
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Showing 3 changed files with 10 additions and 1 deletion.
diff --git a/tcmalloc/cpu_cache.h b/tcmalloc/cpu_cache.h
@@ -171,7 +171,8 @@ class StaticForwarder {
     // increases shift by 1 by itself, so we can not increase it further.
     //
     // TODO(b/271598304):  Complete this experiment.
-    return IsExperimentActive(Experiment::TEST_ONLY_TCMALLOC_512K_SLAB) &&
+    return (IsExperimentActive(Experiment::TEST_ONLY_TCMALLOC_512K_SLAB) ||
+            IsExperimentActive(Experiment::TCMALLOC_WIDER_SLABS)) &&
            !numa_topology().numa_aware();
   }
 

diff --git a/tcmalloc/experiment_config.h b/tcmalloc/experiment_config.h
@@ -25,6 +25,7 @@ enum class Experiment : int {
   TEST_ONLY_TCMALLOC_SHARDED_TRANSFER_CACHE,
   TEST_ONLY_TCMALLOC_FILLER_CHUNKS_PER_ALLOC,
   TCMALLOC_SHORT_LONG_TERM_SUBRELEASE,
+  TCMALLOC_WIDER_SLABS,
   TEST_ONLY_TCMALLOC_512K_SLAB,
   TEST_ONLY_TCMALLOC_USE_ALL_BUCKETS_FOR_FEW_OBJECT_SPANS_IN_CFL,
   TEST_ONLY_TCMALLOC_USE_EXTENDED_SIZE_CLASS_FOR_COLD,
@@ -42,6 +43,7 @@ inline constexpr ExperimentConfig experiments[] = {
     {Experiment::TEST_ONLY_TCMALLOC_SHARDED_TRANSFER_CACHE, "TEST_ONLY_TCMALLOC_SHARDED_TRANSFER_CACHE"},
     {Experiment::TEST_ONLY_TCMALLOC_FILLER_CHUNKS_PER_ALLOC, "TEST_ONLY_TCMALLOC_FILLER_CHUNKS_PER_ALLOC"},
     {Experiment::TCMALLOC_SHORT_LONG_TERM_SUBRELEASE, "TCMALLOC_SHORT_LONG_TERM_SUBRELEASE"},
+    {Experiment::TCMALLOC_WIDER_SLABS, "TCMALLOC_WIDER_SLABS"},
     {Experiment::TEST_ONLY_TCMALLOC_512K_SLAB, "TEST_ONLY_TCMALLOC_512K_SLAB"},
     {Experiment::TEST_ONLY_TCMALLOC_USE_ALL_BUCKETS_FOR_FEW_OBJECT_SPANS_IN_CFL, "TEST_ONLY_TCMALLOC_USE_ALL_BUCKETS_FOR_FEW_OBJECT_SPANS_IN_CFL"},
     {Experiment::TEST_ONLY_TCMALLOC_USE_EXTENDED_SIZE_CLASS_FOR_COLD, "TEST_ONLY_TCMALLOC_USE_EXTENDED_SIZE_CLASS_FOR_COLD"},

diff --git a/tcmalloc/variants.bzl b/tcmalloc/variants.bzl
@@ -120,6 +120,12 @@ test_variants = [
         "deps": ["//tcmalloc:common_8k_pages"],
         "env": {"BORG_EXPERIMENTS": "TEST_ONLY_TCMALLOC_FILLER_CHUNKS_PER_ALLOC"},
     },
+    {
+        "name": "wider_slabs",
+        "malloc": "//tcmalloc",
+        "deps": ["//tcmalloc:common_8k_pages"],
+        "env": {"BORG_EXPERIMENTS": "TCMALLOC_WIDER_SLABS"},
+    },
     {
         "name": "512k_slab",
         "malloc": "//tcmalloc",