making helper function, adding tests

Author: kab163

examples/ipc_shared_memory_release.cpp

@@ -7,13 +7,8 @@
 
 #include <cstddef>
 #include <cstdint>
-#include <cctype>
-#include <cstdio>
-#include <cstring>
-#include <fstream>
 #include <iostream>
 #include <string>
-#include <vector>
 
 #include <unistd.h>
 
@@ -57,44 +52,6 @@ void touch_one_byte_per_page(std::uint8_t* buffer, std::size_t bytes)
   }
 }
 
-std::size_t get_smaps_rss_bytes_for_mapping(const std::string& mapping_name_substr)
-{
-#if defined(__linux__)
-  std::ifstream smaps("/proc/self/smaps");
-  if (!smaps) {
-    return 0;
-  }
-
-  std::size_t rss_kb{0};
-  bool in_target{false};
-
-  std::string line;
-  while (std::getline(smaps, line)) {
-    const bool is_header = (!line.empty() && std::isxdigit(static_cast<unsigned char>(line[0])) && line.find('-') != std::string::npos);
-
-    if (is_header) {
-      in_target = (line.find(mapping_name_substr) != std::string::npos);
-      continue;
-    }
-
-    if (!in_target) {
-      continue;
-    }
-
-    constexpr const char* rss_prefix = "Rss:";
-    if (line.rfind(rss_prefix, 0) == 0) {
-      std::size_t value_kb{0};
-      std::sscanf(line.c_str(), "Rss: %zu kB", &value_kb);
-      rss_kb += value_kb;
-    }
-  }
-
-  return rss_kb * 1024;
-#else
-  (void)mapping_name_substr;
-  return 0;
-#endif
-}
 } // namespace
 
 int main(int, char**)
@@ -112,7 +69,7 @@ int main(int, char**)
   const std::size_t rss_before = umpire::get_process_memory_usage();
   std::cout << "RSS before: " << format_bytes(rss_before) << "\n";
 
-  const std::size_t shm_rss_before = get_smaps_rss_bytes_for_mapping(allocator_name);
+  const std::size_t shm_rss_before = umpire::get_mapping_memory_usage(allocator_name);
   if (shm_rss_before > 0) {
     std::cout << "Shared segment RSS before: " << format_bytes(shm_rss_before) << "\n";
   }
@@ -123,7 +80,7 @@ int main(int, char**)
   const std::size_t rss_after_touch = umpire::get_process_memory_usage();
   std::cout << "RSS after touching allocation: " << format_bytes(rss_after_touch) << "\n";
 
-  const std::size_t shm_rss_after_touch = get_smaps_rss_bytes_for_mapping(allocator_name);
+  const std::size_t shm_rss_after_touch = umpire::get_mapping_memory_usage(allocator_name);
   if (shm_rss_after_touch > 0) {
     std::cout << "Shared segment RSS after touch: " << format_bytes(shm_rss_after_touch) << "\n";
   }
@@ -133,7 +90,7 @@ int main(int, char**)
   const std::size_t rss_after_free = umpire::get_process_memory_usage();
   std::cout << "RSS after deallocate (before release): " << format_bytes(rss_after_free) << "\n";
 
-  const std::size_t shm_rss_after_free = get_smaps_rss_bytes_for_mapping(allocator_name);
+  const std::size_t shm_rss_after_free = umpire::get_mapping_memory_usage(allocator_name);
   if (shm_rss_after_free > 0) {
     std::cout << "Shared segment RSS after deallocate: " << format_bytes(shm_rss_after_free) << "\n";
   }
@@ -143,7 +100,7 @@ int main(int, char**)
   const std::size_t rss_after_release = umpire::get_process_memory_usage();
   std::cout << "RSS after allocator.release(): " << format_bytes(rss_after_release) << "\n";
 
-  const std::size_t shm_rss_after_release = get_smaps_rss_bytes_for_mapping(allocator_name);
+  const std::size_t shm_rss_after_release = umpire::get_mapping_memory_usage(allocator_name);
   if (shm_rss_after_release > 0) {
     std::cout << "Shared segment RSS after release: " << format_bytes(shm_rss_after_release) << "\n";
   } else {

src/umpire/Umpire.cpp

@@ -8,6 +8,8 @@
 #include "umpire/Umpire.hpp"
 
 #include <algorithm>
+#include <cctype>
+#include <cstdio>
 #include <iostream>
 #include <iterator>
 #include <limits>
@@ -172,6 +174,43 @@ std::size_t get_process_memory_usage()
 #endif
 }
 
+std::size_t get_mapping_memory_usage(const std::string& mapping_name)
+{
+#if defined(__linux__)
+  std::ifstream smaps{"/proc/self/smaps"};
+  if (!smaps) {
+    return 0;
+  }
+
+  std::size_t rss_kb{0};
+  bool in_target_mapping{false};
+  std::string line;
+
+  while (std::getline(smaps, line)) {
+    const bool is_header = (!line.empty() && std::isxdigit(static_cast<unsigned char>(line[0])) &&
+                            line.find('-') != std::string::npos);
+
+    if (is_header) {
+      in_target_mapping = (line.find(mapping_name) != std::string::npos);
+      continue;
+    }
+
+    if (!in_target_mapping || line.rfind("Rss:", 0) != 0) {
+      continue;
+    }
+
+    std::size_t value_kb{0};
+    std::sscanf(line.c_str(), "Rss: %zu kB", &value_kb);
+    rss_kb += value_kb;
+  }
+
+  return rss_kb * 1024;
+#else
+  UMPIRE_USE_VAR(mapping_name);
+  return 0;
+#endif
+}
+
 std::size_t get_internal_memory_usage()
 {
   return umpire::ResourceManager::getInstance().getInternalMemoryUsage();

src/umpire/Umpire.hpp

@@ -151,6 +151,15 @@ std::string get_backtrace(void* ptr);
  */
 std::size_t get_process_memory_usage();
 
+/*!
+ * \brief Get resident memory usage for memory mappings whose name contains
+ * the provided substring.
+ *
+ * On Linux, this uses /proc/self/smaps and sums the RSS values for matching
+ * mappings. Returns 0 on unsupported platforms.
+ */
+std::size_t get_mapping_memory_usage(const std::string& mapping_name);
+
 /*!
  * \brief Get high watermark memory usage of the current process (uses underlying
  * system-dependent calls)

src/umpire/resource/HostSharedMemoryResourceImpl.hpp

@@ -320,7 +320,6 @@ class HostSharedMemoryResource::impl {
     offset_to_pointer(m_segment->free_blocks_off, block_ptr);
 
     while (block_ptr != nullptr) {
-#if defined(__linux__)
       char* const block_begin = reinterpret_cast<char*>(block_ptr);
       char* const block_end = block_begin + block_ptr->block_size;
 
@@ -344,7 +343,6 @@ class HostSharedMemoryResource::impl {
                                 << m_segment_name << ": " << strerror(madvise_err));
         }
       }
-#endif
 
       offset_to_pointer(block_ptr->next_block_off, block_ptr);
     }

tests/unit/resource/ipc_shared_memory_resource_tests.cpp

@@ -232,8 +232,6 @@ TEST_F(SharedMemoryTest, UnitTests)
       allocator.deallocate(ptr);
     }
     MPI_Barrier(MPI_COMM_WORLD);
-
-    MPI_Barrier(MPI_COMM_WORLD);
   }
 }
 } // namespace

tests/unit/umpire_tests.cpp

@@ -13,6 +13,7 @@
 TEST(Umpire, ProcessorMemoryStatistics)
 {
   ASSERT_GE(umpire::get_process_memory_usage(), 0);
+  ASSERT_GE(umpire::get_mapping_memory_usage(""), 0);
   ASSERT_GE(umpire::get_device_memory_usage(0), 0);
 }