Pulse extended memory statistics, now report glibc allocations (#19379)

* add malloc_info() to netdata

* report number of arenas

* arenas line chart

CMakeLists.txt

@@ -484,6 +484,14 @@ int main() {
 }
 " HAVE_C_MALLOC_TRIM)
 
+check_c_source_compiles("
+#include <malloc.h>
+int main() {
+        malloc_info(0, stdout);
+        return 0;
+}
+" HAVE_C_MALLOC_INFO)
+
 check_c_source_compiles("
 #define _GNU_SOURCE
 #include <stdio.h>

packaging/cmake/config.cmake.h.in

@@ -98,6 +98,7 @@
 #cmakedefine HAVE_C__GENERIC
 #cmakedefine HAVE_C_MALLOPT
 #cmakedefine HAVE_C_MALLOC_TRIM
+#cmakedefine HAVE_C_MALLOC_INFO
 #cmakedefine HAVE_SETNS
 #cmakedefine HAVE_STRNDUP
 #cmakedefine SSL_HAS_PENDING

src/daemon/pulse/pulse-daemon-memory.c

@@ -9,6 +9,116 @@
 
 struct netdata_buffers_statistics netdata_buffers_statistics = { 0 };
 
+#ifdef HAVE_C_MALLOC_INFO
+#include <malloc.h>
+
+// Helper function to find the last occurrence of a substring in a string
+static char *find_last(const char *haystack, const char *needle, size_t *found) {
+    *found = 0;
+
+    char *last = NULL;
+    char *current = strstr(haystack, needle);
+    while (current) {
+        (*found)++;
+        last = current;
+        current = strstr(current + 1, needle);
+    }
+    return last;
+}
+
+static bool parse_malloc_info(size_t *arenas, size_t *allocated_memory, size_t *used_fast, size_t *used_rest, size_t *used_mmap, size_t *unused_memory) {
+    int found = 0;
+
+    *arenas = 0;
+    *allocated_memory = 0;
+    *used_fast = 0;
+    *used_rest = 0;
+    *used_mmap = 0;
+    *unused_memory = 0;
+
+    // Buffer for malloc_info XML
+    char *buffer = NULL;
+    size_t size = 0;
+    FILE *meminfo = open_memstream(&buffer, &size);
+    if (!meminfo)
+        goto cleanup;
+
+    char *t = malloc(1024);
+
+    // Generate malloc_info XML
+    if(malloc_info(0, meminfo) != 0)
+        goto cleanup;
+
+    fflush(meminfo);
+    fclose(meminfo);
+    meminfo = NULL;
+
+    free(t);
+
+    if(!size || !buffer)
+        goto cleanup;
+
+    // make sure it is terminated
+    buffer[size - 1] = '\0';
+
+    // Find the last </heap>
+    char *last_heap_end = find_last(buffer, "</heap>", arenas);
+    if (!last_heap_end)
+        goto cleanup;
+
+    // Move past the last </heap>
+    char *summary_section = last_heap_end + strlen("</heap>");
+
+    // Parse the summary section using strstr
+    const char *fast_key = "<total type=\"fast\"";
+    const char *rest_key = "<total type=\"rest\"";
+    const char *mmap_key = "<total type=\"mmap\"";
+    const char *system_key = "<system type=\"current\"";
+    char *size_pos;
+
+    // Extract Used Fast
+    char *fast_pos = strstr(summary_section, fast_key);
+    if(!fast_pos || !(size_pos = strstr(fast_pos, "size=\"")))
+        goto cleanup;
+
+    *used_fast = strtoull(size_pos + 6, NULL, 10);
+    found++;
+
+    // Extract Used Rest
+    char *rest_pos = strstr(summary_section, rest_key);
+    if (!rest_pos || !(size_pos = strstr(rest_pos, "size=\"")))
+        goto cleanup;
+
+    *used_rest = strtoull(size_pos + 6, NULL, 10);
+    found++;
+
+    // Extract Used Mmap
+    char *mmap_pos = strstr(summary_section, mmap_key);
+    if (!mmap_pos || !(size_pos = strstr(mmap_pos, "size=\"")))
+        goto cleanup;
+
+    *used_mmap = strtoull(size_pos + 6, NULL, 10);
+    found++;
+
+    // Extract Allocated Memory
+    char *system_pos = strstr(summary_section, system_key);
+    if (!system_pos || !(size_pos = strstr(system_pos, "size=\"")))
+        goto cleanup;
+
+    *allocated_memory = strtoull(size_pos + 6, NULL, 10);
+    found++;
+
+    // Calculate Unused Memory
+    *unused_memory = *allocated_memory > (*used_fast + *used_rest + *used_mmap) ?
+                         *allocated_memory - (*used_fast + *used_rest + *used_mmap) : 0;
+
+cleanup:
+    if(meminfo) fclose(meminfo);
+    if(buffer) free(buffer);
+    return found == 4;
+}
+#endif // HAVE_C_MALLOC_INFO
+
 void pulse_daemon_memory_do(bool extended) {
     {
         static RRDSET *st_memory = NULL;
@@ -285,4 +395,72 @@ void pulse_daemon_memory_do(bool extended) {
 
     // ----------------------------------------------------------------------------------------------------------------
 
+#ifdef HAVE_C_MALLOC_INFO
+    size_t glibc_arenas, glibc_allocated_memory, glibc_used_fast, glibc_used_rest, glibc_used_mmap, glibc_unused_memory;
+    if(parse_malloc_info(&glibc_arenas, &glibc_allocated_memory, &glibc_used_fast, &glibc_used_rest, &glibc_used_mmap, &glibc_unused_memory)) {
+        if (glibc_arenas) {
+            static RRDSET *st_arenas = NULL;
+            static RRDDIM *rd_arenas = NULL;
+
+            if (unlikely(!st_arenas)) {
+                st_arenas = rrdset_create_localhost(
+                    "netdata",
+                    "glibc_arenas",
+                    NULL,
+                    "Memory Usage",
+                    NULL,
+                    "Glibc Memory Arenas",
+                    "bytes",
+                    "netdata",
+                    "pulse",
+                    130104,
+                    localhost->rrd_update_every,
+                    RRDSET_TYPE_LINE);
+
+                rd_arenas = rrddim_add(st_arenas, "arenas", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            }
+
+            // the sum of all these needs to be above at the total buffers calculation
+            rrddim_set_by_pointer(st_arenas, rd_arenas, (collected_number)glibc_arenas);
+            rrdset_done(st_arenas);
+        }
+
+        if (glibc_allocated_memory > 0 && glibc_used_fast + glibc_used_rest + glibc_used_mmap + glibc_unused_memory > 0) {
+            static RRDSET *st_malloc = NULL;
+            static RRDDIM *rd_unused = NULL;
+            static RRDDIM *rd_fast = NULL;
+            static RRDDIM *rd_rest = NULL;
+            static RRDDIM *rd_mmap = NULL;
+
+            if (unlikely(!st_malloc)) {
+                st_malloc = rrdset_create_localhost(
+                    "netdata",
+                    "glibc_memory",
+                    NULL,
+                    "Memory Usage",
+                    NULL,
+                    "Glibc Memory Usage",
+                    "bytes",
+                    "netdata",
+                    "pulse",
+                    130105,
+                    localhost->rrd_update_every,
+                    RRDSET_TYPE_STACKED);
+
+                rd_unused = rrddim_add(st_malloc, "unused", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                rd_fast = rrddim_add(st_malloc, "fast", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                rd_rest = rrddim_add(st_malloc, "rest", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                rd_mmap = rrddim_add(st_malloc, "mmap", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            }
+
+            // the sum of all these needs to be above at the total buffers calculation
+            rrddim_set_by_pointer(st_malloc, rd_unused, (collected_number)glibc_unused_memory);
+            rrddim_set_by_pointer(st_malloc, rd_fast, (collected_number)glibc_used_fast);
+            rrddim_set_by_pointer(st_malloc, rd_rest, (collected_number)glibc_used_rest);
+            rrddim_set_by_pointer(st_malloc, rd_mmap, (collected_number)glibc_used_mmap);
+            rrdset_done(st_malloc);
+        }
+    }
+#endif
+
 }