GC page profiler

src/Makefile

@@ -44,7 +44,7 @@ SRCS := \
 	jltypes gf typemap smallintset ast builtins module interpreter symbol \
 	dlload sys init task array genericmemory staticdata toplevel jl_uv datatype \
 	simplevector runtime_intrinsics precompile jloptions mtarraylist \
-	threading scheduler stackwalk gc gc-debug gc-pages gc-stacks gc-alloc-profiler method \
+	threading scheduler stackwalk gc gc-debug gc-pages gc-stacks gc-alloc-profiler gc-page-profiler method \
 	jlapi signal-handling safepoint timing subtype rtutils gc-heap-snapshot \
 	crc32c APInt-C processor ircode opaque_closure codegen-stubs coverage runtime_ccall
 

src/gc-page-profiler.c

@@ -0,0 +1,167 @@
+// This file is a part of Julia. License is MIT: https://julialang.org/license
+
+#include "gc-page-profiler.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// whether page profiling is enabled
+int page_profile_enabled;
+// number of pages written
+size_t page_profile_pages_written;
+// stream to write page profile to
+ios_t *page_profile_stream;
+// mutex for page profile
+uv_mutex_t page_profile_lock;
+
+gc_page_profiler_serializer_t gc_page_serializer_create(void) JL_NOTSAFEPOINT
+{
+    gc_page_profiler_serializer_t serializer;
+    if (__unlikely(page_profile_enabled)) {
+        arraylist_new(&serializer.typestrs, GC_PAGE_SZ);
+    }
+    else {
+        serializer.typestrs.len = 0;
+    }
+    return serializer;
+}
+
+void gc_page_serializer_init(gc_page_profiler_serializer_t *serializer,
+                             jl_gc_pagemeta_t *pg) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        serializer->typestrs.len = 0;
+        serializer->data = (char *)pg->data;
+        serializer->osize = pg->osize;
+    }
+}
+
+void gc_page_serializer_destroy(gc_page_profiler_serializer_t *serializer) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        arraylist_free(&serializer->typestrs);
+    }
+}
+
+void gc_page_serializer_write(gc_page_profiler_serializer_t *serializer,
+                              const char *str) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        arraylist_push(&serializer->typestrs, (void *)str);
+    }
+}
+
+void gc_enable_page_profile(void) JL_NOTSAFEPOINT
+{
+    page_profile_enabled = 1;
+}
+
+void gc_disable_page_profile(void) JL_NOTSAFEPOINT
+{
+    page_profile_enabled = 0;
+}
+
+int gc_page_profile_is_enabled(void) JL_NOTSAFEPOINT
+{
+    return page_profile_enabled;
+}
+
+void gc_page_profile_write_preamble(gc_page_profiler_serializer_t *serializer)
+    JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        char str[GC_TYPE_STR_MAXLEN];
+        snprintf(str, GC_TYPE_STR_MAXLEN,
+                 "{\"address\": \"%p\",\"object_size\": %d,\"objects\": [",
+                 serializer->data, serializer->osize);
+        ios_write(page_profile_stream, str, strlen(str));
+    }
+}
+
+void gc_page_profile_write_epilogue(gc_page_profiler_serializer_t *serializer)
+    JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        const char *str = "]}";
+        ios_write(page_profile_stream, str, strlen(str));
+    }
+}
+
+void gc_page_profile_write_comma(gc_page_profiler_serializer_t *serializer) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        // write comma if not first page
+        if (page_profile_pages_written > 0) {
+            const char *str = ",";
+            ios_write(page_profile_stream, str, strlen(str));
+        }
+    }
+}
+
+void gc_page_profile_write_to_file(gc_page_profiler_serializer_t *serializer)
+    JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        // write to file
+        uv_mutex_lock(&page_profile_lock);
+        gc_page_profile_write_comma(serializer);
+        gc_page_profile_write_preamble(serializer);
+        char str[GC_TYPE_STR_MAXLEN];
+        for (size_t i = 0; i < serializer->typestrs.len; i++) {
+            const char *name = (const char *)serializer->typestrs.items[i];
+            if (name == GC_SERIALIZER_EMPTY) {
+                snprintf(str, GC_TYPE_STR_MAXLEN, "\"empty\",");
+            }
+            else if (name == GC_SERIALIZER_GARBAGE) {
+                snprintf(str, GC_TYPE_STR_MAXLEN, "\"garbage\",");
+            }
+            else {
+                snprintf(str, GC_TYPE_STR_MAXLEN, "\"%s\",", name);
+            }
+            // remove trailing comma for last element
+            if (i == serializer->typestrs.len - 1) {
+                str[strlen(str) - 1] = '\0';
+            }
+            ios_write(page_profile_stream, str, strlen(str));
+        }
+        gc_page_profile_write_epilogue(serializer);
+        page_profile_pages_written++;
+        uv_mutex_unlock(&page_profile_lock);
+    }
+}
+
+void gc_page_profile_write_json_preamble(ios_t *stream) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        uv_mutex_lock(&page_profile_lock);
+        const char *str = "{\"pages\": [";
+        ios_write(stream, str, strlen(str));
+        uv_mutex_unlock(&page_profile_lock);
+    }
+}
+
+void gc_page_profile_write_json_epilogue(ios_t *stream) JL_NOTSAFEPOINT
+{
+    if (__unlikely(page_profile_enabled)) {
+        uv_mutex_lock(&page_profile_lock);
+        const char *str = "]}";
+        ios_write(stream, str, strlen(str));
+        uv_mutex_unlock(&page_profile_lock);
+    }
+}
+
+JL_DLLEXPORT void jl_gc_take_page_profile(ios_t *stream)
+{
+    gc_enable_page_profile();
+    page_profile_pages_written = 0;
+    page_profile_stream = stream;
+    gc_page_profile_write_json_preamble(stream);
+    jl_gc_collect(JL_GC_FULL);
+    gc_page_profile_write_json_epilogue(stream);
+    gc_disable_page_profile();
+}
+
+#ifdef __cplusplus
+}
+#endif

src/gc-page-profiler.h

@@ -0,0 +1,63 @@
+// This file is a part of Julia. License is MIT: https://julialang.org/license
+
+#ifndef GC_PAGE_PROFILER_H
+#define GC_PAGE_PROFILER_H
+
+#include "gc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define GC_TYPE_STR_MAXLEN (512)
+
+typedef struct {
+    arraylist_t typestrs;
+    char *data;
+    int osize;
+} gc_page_profiler_serializer_t;
+
+// mutex for page profile
+extern uv_mutex_t page_profile_lock;
+
+// Serializer functions
+gc_page_profiler_serializer_t gc_page_serializer_create(void) JL_NOTSAFEPOINT;
+void gc_page_serializer_init(gc_page_profiler_serializer_t *serializer, jl_gc_pagemeta_t *pg) JL_NOTSAFEPOINT;
+void gc_page_serializer_destroy(gc_page_profiler_serializer_t *serializer) JL_NOTSAFEPOINT;
+void gc_page_serializer_write(gc_page_profiler_serializer_t *serializer, const char *str) JL_NOTSAFEPOINT;
+// Page profile functions
+#define GC_SERIALIZER_EMPTY ((const char *)0x1)
+#define GC_SERIALIZER_GARBAGE ((const char *)0x2)
+STATIC_INLINE void gc_page_profile_write_empty_page(gc_page_profiler_serializer_t *serializer,
+                                 int enabled) JL_NOTSAFEPOINT
+{
+    if (__unlikely(enabled)) {
+        gc_page_serializer_write(serializer, GC_SERIALIZER_EMPTY);
+    }
+}
+STATIC_INLINE void gc_page_profile_write_garbage(gc_page_profiler_serializer_t *serializer,
+                                                 int enabled) JL_NOTSAFEPOINT
+{
+    if (__unlikely(enabled)) {
+        gc_page_serializer_write(serializer, GC_SERIALIZER_GARBAGE);
+    }
+}
+STATIC_INLINE void gc_page_profile_write_live_obj(gc_page_profiler_serializer_t *serializer,
+                                                  jl_taggedvalue_t *v,
+                                                  int enabled) JL_NOTSAFEPOINT
+{
+    if (__unlikely(enabled)) {
+        const char *name = jl_typeof_str(jl_valueof(v));
+        gc_page_serializer_write(serializer, name);
+    }
+}
+void gc_enable_page_profile(void) JL_NOTSAFEPOINT;
+void gc_disable_page_profile(void) JL_NOTSAFEPOINT;
+int gc_page_profile_is_enabled(void) JL_NOTSAFEPOINT;
+void gc_page_profile_write_to_file(gc_page_profiler_serializer_t *serializer) JL_NOTSAFEPOINT;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // GC_PAGE_PROFILER_H