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diff --git a/mozglue/baseprofiler/public/ProfilerBufferSize.h b/mozglue/baseprofiler/public/ProfilerBufferSize.h
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+++ b/mozglue/baseprofiler/public/ProfilerBufferSize.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef ProfilerBufferSize_h
+#define ProfilerBufferSize_h
+
+#include "mozilla/ProfileBufferChunkManager.h"
+
+// We need to decide how many chunks of what size we want to fit in the given
+// total maximum capacity for this process, in the (likely) context of
+// multiple processes doing the same choice and having an inter-process
+// mechanism to control the overall memory limit.
+
+// The buffer size is provided as a number of "entries", this is their size in
+// bytes.
+constexpr static uint32_t scBytesPerEntry = 8;
+
+// Minimum chunk size allowed, enough for at least one stack.
+constexpr static uint32_t scMinimumChunkSize =
+    2 * mozilla::ProfileBufferChunkManager::scExpectedMaximumStackSize;
+
+// Ideally we want at least 2 unreleased chunks to work with (1 current and 1
+// next), and 2 released chunks (so that one can be recycled when old, leaving
+// one with some data).
+constexpr static uint32_t scMinimumNumberOfChunks = 4;
+
+// And we want to limit chunks to a maximum size, which is a compromise
+// between:
+// - A big size, which helps with reducing the rate of allocations and IPCs.
+// - A small size, which helps with equalizing the duration of recorded data
+//   (as the inter-process controller will discard the oldest chunks in all
+//   Firefox processes).
+constexpr static uint32_t scMaximumChunkSize = 1024 * 1024;
+
+// Limit to 128MiB as a lower buffer size usually isn't enough.
+constexpr static uint32_t scMinimumBufferSize = 128u * 1024u * 1024u;
+// Note: Keep in sync with GeckoThread.maybeStartGeckoProfiler:
+// https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoThread.java
+constexpr static uint32_t scMinimumBufferEntries =
+    scMinimumBufferSize / scBytesPerEntry;
+
+// Limit to 2GiB.
+constexpr static uint32_t scMaximumBufferSize = 2u * 1024u * 1024u * 1024u;
+constexpr static uint32_t scMaximumBufferEntries =
+    scMaximumBufferSize / scBytesPerEntry;
+
+constexpr static uint32_t ClampToAllowedEntries(uint32_t aEntries) {
+  if (aEntries <= scMinimumBufferEntries) {
+    return scMinimumBufferEntries;
+  }
+  if (aEntries >= scMaximumBufferEntries) {
+    return scMaximumBufferEntries;
+  }
+  return aEntries;
+}
+
+#endif  // ProfilerBufferSize_h