diff --git a/libc/NOTICE b/libc/NOTICE
index 88d022f..c52a102 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -891,6 +891,22 @@
 -------------------------------------------------------------------
 
 Copyright (C) 2024 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+-------------------------------------------------------------------
+
+Copyright (C) 2024 The Android Open Source Project
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/libc/malloc_debug/Android.bp b/libc/malloc_debug/Android.bp
index 5d61801..1864138 100644
--- a/libc/malloc_debug/Android.bp
+++ b/libc/malloc_debug/Android.bp
@@ -135,6 +135,7 @@
         "tests/log_fake.cpp",
         "tests/libc_fake.cpp",
         "tests/malloc_debug_config_tests.cpp",
+        "tests/malloc_debug_record_data_tests.cpp",
         "tests/malloc_debug_unit_tests.cpp",
     ],
 
diff --git a/libc/malloc_debug/RecordData.cpp b/libc/malloc_debug/RecordData.cpp
index f832f03..1df0b0c 100644
--- a/libc/malloc_debug/RecordData.cpp
+++ b/libc/malloc_debug/RecordData.cpp
@@ -38,7 +38,6 @@
 
 #include <mutex>
 
-#include <android-base/stringprintf.h>
 #include <memory_trace/MemoryTrace.h>
 
 #include "Config.h"
@@ -150,10 +149,20 @@
   cur_index_ = 0U;
   file_ = config.record_allocs_file();
 
+  pagemap_fd_ = TEMP_FAILURE_RETRY(open("/proc/self/pagemap", O_RDONLY | O_CLOEXEC));
+  if (pagemap_fd_ == -1) {
+    error_log("Unable to open /proc/self/pagemap: %s", strerror(errno));
+    return false;
+  }
+
   return true;
 }
 
 RecordData::~RecordData() {
+  if (pagemap_fd_ != -1) {
+    close(pagemap_fd_);
+  }
+
   pthread_key_delete(key_);
 }
 
@@ -180,3 +189,78 @@
 
   return InternalReserveEntry();
 }
+
+static inline bool IsPagePresent(uint64_t page_data) {
+  // Page Present is bit 63
+  return (page_data & (1ULL << 63)) != 0;
+}
+
+int64_t RecordData::GetPresentBytes(void* ptr, size_t alloc_size) {
+  uintptr_t addr = reinterpret_cast<uintptr_t>(ptr);
+  if (addr == 0 || alloc_size == 0) {
+    return -1;
+  }
+
+  uintptr_t page_size = getpagesize();
+  uintptr_t page_size_mask = page_size - 1;
+
+  size_t start_page = (addr & ~page_size_mask) / page_size;
+  size_t last_page = ((addr + alloc_size - 1) & ~page_size_mask) / page_size;
+
+  constexpr size_t kMaxReadPages = 1024;
+  uint64_t page_data[kMaxReadPages];
+
+  int64_t present_bytes = 0;
+  size_t cur_page = start_page;
+  while (cur_page <= last_page) {
+    size_t num_pages = last_page - cur_page + 1;
+    size_t last_page_index;
+    if (num_pages > kMaxReadPages) {
+      num_pages = kMaxReadPages;
+      last_page_index = num_pages;
+    } else {
+      // Handle the last page differently, so do not handle it in the loop.
+      last_page_index = num_pages - 1;
+    }
+    ssize_t bytes_read =
+        pread64(pagemap_fd_, page_data, num_pages * sizeof(uint64_t), cur_page * sizeof(uint64_t));
+    if (bytes_read <= 0) {
+      error_log("Failed to read page data: %s", strerror(errno));
+      return -1;
+    }
+
+    size_t page_index = 0;
+    // Handling the first page is special, handle it separately.
+    if (cur_page == start_page) {
+      if (IsPagePresent(page_data[0])) {
+        present_bytes = page_size - (addr & page_size_mask);
+        if (present_bytes >= alloc_size) {
+          // The allocation fits on a single page and that page is present.
+          return alloc_size;
+        }
+      } else if (start_page == last_page) {
+        // Only one page that isn't present.
+        return 0;
+      }
+      page_index = 1;
+    }
+
+    for (; page_index < last_page_index; page_index++) {
+      if (IsPagePresent(page_data[page_index])) {
+        present_bytes += page_size;
+      }
+    }
+
+    cur_page += last_page_index;
+
+    // Check the last page in the allocation.
+    if (cur_page == last_page) {
+      if (IsPagePresent(page_data[num_pages - 1])) {
+        present_bytes += ((addr + alloc_size - 1) & page_size_mask) + 1;
+      }
+      return present_bytes;
+    }
+  }
+
+  return present_bytes;
+}
diff --git a/libc/malloc_debug/RecordData.h b/libc/malloc_debug/RecordData.h
index ce71da1..bf5cc57 100644
--- a/libc/malloc_debug/RecordData.h
+++ b/libc/malloc_debug/RecordData.h
@@ -56,6 +56,8 @@
   const std::string& file() { return file_; }
   pthread_key_t key() { return key_; }
 
+  int64_t GetPresentBytes(void* pointer, size_t size);
+
   static void WriteEntriesOnExit();
 
  private:
@@ -74,6 +76,7 @@
   std::vector<memory_trace::Entry> entries_;
   size_t cur_index_;
   std::string file_;
+  int pagemap_fd_ = -1;
 
   BIONIC_DISALLOW_COPY_AND_ASSIGN(RecordData);
 };
diff --git a/libc/malloc_debug/malloc_debug.cpp b/libc/malloc_debug/malloc_debug.cpp
index fce6c24..7e96169 100644
--- a/libc/malloc_debug/malloc_debug.cpp
+++ b/libc/malloc_debug/malloc_debug.cpp
@@ -682,6 +682,13 @@
   if (DebugCallsDisabled() || pointer == nullptr) {
     return g_dispatch->free(pointer);
   }
+
+  size_t size;
+  if (g_debug->config().options() & RECORD_ALLOCS) {
+    // Need to get the size before disabling debug calls.
+    size = debug_malloc_usable_size(pointer);
+  }
+
   ScopedConcurrentLock lock;
   ScopedDisableDebugCalls disable;
   ScopedBacktraceSignalBlocker blocked;
@@ -690,11 +697,16 @@
     return;
   }
 
+  int64_t present_bytes = -1;
   memory_trace::Entry* entry = nullptr;
   if (g_debug->config().options() & RECORD_ALLOCS) {
     // In order to preserve the order of operations, reserve the entry before
     // performing the operation.
     entry = g_debug->record->ReserveEntry();
+
+    // Need to get the present bytes before the pointer is freed in case the
+    // memory is released during the free call.
+    present_bytes = g_debug->record->GetPresentBytes(pointer, size);
   }
 
   TimedResult result = InternalFree(pointer);
@@ -703,6 +715,7 @@
     *entry = memory_trace::Entry{.tid = gettid(),
                                  .type = memory_trace::FREE,
                                  .ptr = reinterpret_cast<uint64_t>(pointer),
+                                 .present_bytes = present_bytes,
                                  .start_ns = result.GetStartTimeNS(),
                                  .end_ns = result.GetEndTimeNS()};
   }
@@ -815,6 +828,13 @@
   if (DebugCallsDisabled()) {
     return g_dispatch->realloc(pointer, bytes);
   }
+
+  size_t old_size;
+  if (pointer != nullptr && g_debug->config().options() & RECORD_ALLOCS) {
+    // Need to get the size before disabling debug calls.
+    old_size = debug_malloc_usable_size(pointer);
+  }
+
   ScopedConcurrentLock lock;
   ScopedDisableDebugCalls disable;
   ScopedBacktraceSignalBlocker blocked;
@@ -845,6 +865,13 @@
     return nullptr;
   }
 
+  int64_t present_bytes = -1;
+  if (g_debug->config().options() & RECORD_ALLOCS) {
+    // Need to get the present bytes before the pointer is freed in case the
+    // memory is released during the free call.
+    present_bytes = g_debug->record->GetPresentBytes(pointer, old_size);
+  }
+
   if (bytes == 0) {
     TimedResult result = InternalFree(pointer);
 
@@ -854,6 +881,7 @@
                                    .ptr = 0,
                                    .size = 0,
                                    .u.old_ptr = reinterpret_cast<uint64_t>(pointer),
+                                   .present_bytes = present_bytes,
                                    .start_ns = result.GetStartTimeNS(),
                                    .end_ns = result.GetEndTimeNS()};
     }
@@ -957,6 +985,7 @@
                                  .ptr = reinterpret_cast<uint64_t>(new_pointer),
                                  .size = bytes,
                                  .u.old_ptr = reinterpret_cast<uint64_t>(pointer),
+                                 .present_bytes = present_bytes,
                                  .start_ns = result.GetStartTimeNS(),
                                  .end_ns = result.GetEndTimeNS()};
   }
diff --git a/libc/malloc_debug/tests/malloc_debug_record_data_tests.cpp b/libc/malloc_debug/tests/malloc_debug_record_data_tests.cpp
new file mode 100644
index 0000000..b94dc8f
--- /dev/null
+++ b/libc/malloc_debug/tests/malloc_debug_record_data_tests.cpp
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <gtest/gtest.h>
+
+#include "Config.h"
+#include "RecordData.h"
+
+#include "log_fake.h"
+
+class MallocDebugRecordDataTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    page_size_ = getpagesize();
+    Config config;
+    ASSERT_TRUE(config.Init("record_allocs"));
+    ASSERT_TRUE(record_.Initialize(config));
+  }
+
+  uint8_t* AllocPageAligned(size_t alloc_pages) {
+    uint8_t* ptr = reinterpret_cast<uint8_t*>(memalign(page_size_, alloc_pages * page_size_));
+    if (ptr == nullptr) {
+      return nullptr;
+    }
+    // Release all the pages so the test can make them present.
+    EXPECT_EQ(0, madvise(ptr, page_size_ * alloc_pages, MADV_DONTNEED));
+    return ptr;
+  }
+
+  size_t page_size_;
+  RecordData record_;
+};
+
+TEST_F(MallocDebugRecordDataTest, get_present_bytes_error) {
+  EXPECT_EQ(-1, record_.GetPresentBytes(nullptr, 1000));
+  EXPECT_EQ(-1, record_.GetPresentBytes(reinterpret_cast<void*>(1000), 0));
+}
+
+TEST_F(MallocDebugRecordDataTest, get_present_bytes_edge_cases) {
+  // Need two pages to check allocations crossing over the page.
+  size_t alloc_pages = 2;
+  uint8_t* ptr = AllocPageAligned(alloc_pages);
+  ASSERT_TRUE(ptr != nullptr);
+  memset(ptr, 1, alloc_pages * page_size_);
+
+  EXPECT_EQ(20, record_.GetPresentBytes(ptr, 20));
+  EXPECT_EQ(page_size_ + 20, record_.GetPresentBytes(ptr, page_size_ + 20));
+  EXPECT_EQ(17, record_.GetPresentBytes(&ptr[page_size_ - 20], 17));
+  EXPECT_EQ(32, record_.GetPresentBytes(&ptr[page_size_ - 16], 32));
+  EXPECT_EQ(page_size_, record_.GetPresentBytes(ptr, page_size_));
+  EXPECT_EQ(page_size_ * 2, record_.GetPresentBytes(ptr, page_size_ * 2));
+}
+
+TEST_F(MallocDebugRecordDataTest, get_present_bytes_first_page_not_present) {
+  uint8_t* ptr = AllocPageAligned(2);
+  ASSERT_TRUE(ptr != nullptr);
+  ptr[page_size_] = 1;
+
+  EXPECT_EQ(0, record_.GetPresentBytes(ptr, page_size_));
+  EXPECT_EQ(3996, record_.GetPresentBytes(&ptr[100], page_size_ * 2 - 200));
+}
+
+TEST_F(MallocDebugRecordDataTest, get_present_bytes_last_page_not_present) {
+  uint8_t* ptr = AllocPageAligned(2);
+  ASSERT_TRUE(ptr != nullptr);
+  ptr[0] = 1;
+
+  EXPECT_EQ(3596, record_.GetPresentBytes(&ptr[500], page_size_ * 2 - 600));
+}
+
+TEST_F(MallocDebugRecordDataTest, get_present_bytes_large) {
+  // Needs to match the kMaxReadPages from GetPresentBytes
+  constexpr size_t kMaxReadPages = 1024;
+  // Allocate large enough that it requires at least two preads.
+  size_t alloc_pages = 2 * kMaxReadPages;
+  uint8_t* ptr = AllocPageAligned(alloc_pages);
+  ASSERT_TRUE(ptr != nullptr);
+  // Make sure that there are different number of pages present in the first
+  // read than in the second read.
+  ptr[0] = 1;
+  ptr[page_size_] = 1;
+  ptr[page_size_ * 4] = 1;
+  // Should be in the second read.
+  size_t start = kMaxReadPages * page_size_;
+  ptr[start + page_size_ * 2] = 1;
+  ptr[start + page_size_ * 4] = 1;
+  ptr[start + page_size_ * 8] = 1;
+  ptr[start + page_size_ * 9] = 1;
+
+  EXPECT_EQ(page_size_ * 7, record_.GetPresentBytes(ptr, alloc_pages * page_size_));
+
+  // Make the entire allocation resident for the next few tests.
+  for (size_t i = 0; i < alloc_pages; i++) {
+    ptr[i * page_size_] = 1;
+  }
+
+  EXPECT_EQ(page_size_ * kMaxReadPages, record_.GetPresentBytes(ptr, page_size_ * kMaxReadPages));
+  EXPECT_EQ(page_size_ * (kMaxReadPages + 1),
+            record_.GetPresentBytes(ptr, page_size_ * (kMaxReadPages + 1)));
+  EXPECT_EQ(page_size_ * kMaxReadPages - 50,
+            record_.GetPresentBytes(ptr, page_size_ * kMaxReadPages - 50));
+  EXPECT_EQ(page_size_ * (kMaxReadPages + 1) - 50,
+            record_.GetPresentBytes(ptr, page_size_ * (kMaxReadPages + 1) - 50));
+}
diff --git a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
index c808dc0..b24f4ad 100644
--- a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
+++ b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
@@ -45,6 +45,7 @@
 #include <platform/bionic/macros.h>
 #include <private/bionic_malloc_dispatch.h>
 
+#include <memory_trace/MemoryTrace.h>
 #include <unwindstack/Unwinder.h>
 
 #include "Config.h"
@@ -202,6 +203,44 @@
   }
 }
 
+static void VerifyRecordEntries(const std::vector<memory_trace::Entry>& expected,
+                                std::string& actual) {
+  ASSERT_TRUE(expected.size() != 0);
+  // Convert the text to entries.
+  std::vector<memory_trace::Entry> actual_entries;
+  for (const auto& line : android::base::Split(actual, "\n")) {
+    if (line.empty()) {
+      continue;
+    }
+    memory_trace::Entry entry;
+    std::string error;
+    ASSERT_TRUE(memory_trace::FillInEntryFromString(line, entry, error)) << error;
+    actual_entries.emplace_back(entry);
+  }
+  auto expected_iter = expected.begin();
+  for (const auto& actual_entry : actual_entries) {
+    if (actual_entry.type == memory_trace::THREAD_DONE) {
+      // Skip thread done entries.
+      continue;
+    }
+    ASSERT_NE(expected_iter, expected.end())
+        << "Found extra entry " << memory_trace::CreateStringFromEntry(*expected_iter);
+    SCOPED_TRACE(testing::Message()
+                 << "\nExpected entry:\n  " << memory_trace::CreateStringFromEntry(*expected_iter)
+                 << "\nActual entry:\n  " << memory_trace::CreateStringFromEntry(actual_entry));
+    EXPECT_EQ(actual_entry.type, expected_iter->type);
+    EXPECT_EQ(actual_entry.ptr, expected_iter->ptr);
+    EXPECT_EQ(actual_entry.size, expected_iter->size);
+    EXPECT_EQ(actual_entry.u.old_ptr, expected_iter->u.old_ptr);
+    EXPECT_EQ(actual_entry.present_bytes, expected_iter->present_bytes);
+    // Verify the timestamps are non-zero.
+    EXPECT_NE(actual_entry.start_ns, 0U);
+    EXPECT_NE(actual_entry.end_ns, 0U);
+    ++expected_iter;
+  }
+  EXPECT_TRUE(expected_iter == expected.end()) << "Not all expected entries found.";
+}
+
 void VerifyAllocCalls(bool all_options) {
   size_t alloc_size = 1024;
 
@@ -2457,6 +2496,114 @@
   ASSERT_STREQ("", getFakeLogPrint().c_str());
 }
 
+TEST_F(MallocDebugTest, record_allocs_present_bytes_check) {
+  InitRecordAllocs("record_allocs record_allocs_on_exit");
+
+  // The filename created on exit always appends the pid.
+  // Modify the variable so the file is deleted at the end of the test.
+  record_filename += '.' + std::to_string(getpid());
+
+  std::vector<memory_trace::Entry> expected;
+  void* ptr = debug_malloc(100);
+  expected.push_back(memory_trace::Entry{
+      .type = memory_trace::MALLOC, .ptr = reinterpret_cast<uint64_t>(ptr), .size = 100});
+
+  // Make the entire allocation present.
+  memset(ptr, 1, 100);
+
+  int64_t real_size = debug_malloc_usable_size(ptr);
+  debug_free(ptr);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::FREE,
+                                         .ptr = reinterpret_cast<uint64_t>(ptr),
+                                         .present_bytes = real_size});
+
+  ptr = debug_malloc(4096);
+  expected.push_back(memory_trace::Entry{
+      .type = memory_trace::MALLOC, .ptr = reinterpret_cast<uint64_t>(ptr), .size = 4096});
+
+  memset(ptr, 1, 4096);
+  real_size = debug_malloc_usable_size(ptr);
+  void* new_ptr = debug_realloc(ptr, 8192);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::REALLOC,
+                                         .ptr = reinterpret_cast<uint64_t>(new_ptr),
+                                         .size = 8192,
+                                         .u.old_ptr = reinterpret_cast<uint64_t>(ptr),
+                                         .present_bytes = real_size});
+
+  memset(new_ptr, 1, 8192);
+  real_size = debug_malloc_usable_size(new_ptr);
+  debug_free(new_ptr);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::FREE,
+                                         .ptr = reinterpret_cast<uint64_t>(new_ptr),
+                                         .present_bytes = real_size});
+
+  ptr = debug_malloc(4096);
+  expected.push_back(memory_trace::Entry{
+      .type = memory_trace::MALLOC, .ptr = reinterpret_cast<uint64_t>(ptr), .size = 4096});
+  memset(ptr, 1, 4096);
+
+  // Verify a free realloc does update the present bytes.
+  real_size = debug_malloc_usable_size(ptr);
+  EXPECT_TRUE(debug_realloc(ptr, 0) == nullptr);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::REALLOC,
+                                         .ptr = 0,
+                                         .u.old_ptr = reinterpret_cast<uint64_t>(ptr),
+                                         .present_bytes = real_size});
+
+  // Call the exit function manually.
+  debug_finalize();
+
+  // Read all of the contents.
+  std::string actual;
+  ASSERT_TRUE(android::base::ReadFileToString(record_filename, &actual));
+  VerifyRecordEntries(expected, actual);
+
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
+TEST_F(MallocDebugTest, record_allocs_not_all_bytes_present) {
+  InitRecordAllocs("record_allocs record_allocs_on_exit");
+
+  // The filename created on exit always appends the pid.
+  // Modify the variable so the file is deleted at the end of the test.
+  record_filename += '.' + std::to_string(getpid());
+
+  std::vector<memory_trace::Entry> expected;
+  size_t pagesize = getpagesize();
+  void* ptr = debug_memalign(pagesize, pagesize * 8);
+  ASSERT_TRUE(ptr != nullptr);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::MEMALIGN,
+                                         .ptr = reinterpret_cast<uint64_t>(ptr),
+                                         .size = pagesize * 8,
+                                         .u.align = pagesize});
+
+  // Mark only some pages in use.
+  uint8_t* data = reinterpret_cast<uint8_t*>(ptr);
+  // Make sure the memory is not in use.
+  ASSERT_EQ(0, madvise(ptr, pagesize * 8, MADV_PAGEOUT));
+  // Dirty three non-consecutive pages.
+  data[0] = 1;
+  data[pagesize * 2] = 1;
+  data[pagesize * 4] = 1;
+
+  debug_free(ptr);
+  expected.push_back(memory_trace::Entry{.type = memory_trace::FREE,
+                                         .ptr = reinterpret_cast<uint64_t>(ptr),
+                                         .present_bytes = static_cast<int64_t>(pagesize) * 3});
+
+  // Call the exit function manually.
+  debug_finalize();
+
+  // Read all of the contents.
+  std::string actual;
+  ASSERT_TRUE(android::base::ReadFileToString(record_filename, &actual));
+  VerifyRecordEntries(expected, actual);
+
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ("", getFakeLogPrint().c_str());
+}
+
 TEST_F(MallocDebugTest, verify_pointers) {
   Init("verify_pointers");