make sample interval and sample depth configurable options

see humanmade#2 and phacility#80 Signed-off-by: Slach <[email protected]>
Slach · Apr 29, 2018 · d9ee744 · d9ee744
1 parent 05871ae
commit d9ee744
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Showing 2 changed files with 22 additions and 6 deletions.
diff --git a/extension/php_xhprof.h b/extension/php_xhprof.h
@@ -64,7 +64,8 @@ extern zend_module_entry xhprof_module_entry;
 #define XHPROF_FLAGS_MEMORY        0x0004   /* gather memory usage for funcs */
 
 /* Constants for XHPROF_MODE_SAMPLED        */
-#define XHPROF_SAMPLING_INTERVAL       100000      /* In microsecs        */
+#define XHPROF_DEFAULT_SAMPLING_INTERVAL       100000      /* In microsecs        */
+#define XHPROF_MINIMAL_SAMPLING_INTERVAL          100      /* In microsecs        */
 
 /* Constant for ignoring functions, transparent to hierarchical profile */
 #define XHPROF_MAX_IGNORED_FUNCTIONS  256
@@ -269,8 +270,9 @@ ZEND_BEGIN_MODULE_GLOBALS(xhprof)
     struct timeval   last_sample_time;
     uint64           last_sample_tsc;
     /* XHPROF_SAMPLING_INTERVAL in ticks */
+    long             sampling_interval;
     uint64           sampling_interval_tsc;
-
+    int              sampling_depth;
     /* XHProf flags */
     uint32 xhprof_flags;
 

diff --git a/extension/xhprof.c b/extension/xhprof.c
@@ -103,7 +103,18 @@ PHP_INI_BEGIN()
  * directory specified by this ini setting.
  */
 PHP_INI_ENTRY("xhprof.output_dir", "", PHP_INI_ALL, NULL)
+/* sampling_interval:
+ * Sampling interval to be used by the sampling profiler, in microseconds.
+ */
+#define STRINGIFY_(X) #X
+#define STRINGIFY(X) STRINGIFY_(X)
+
+STD_PHP_INI_ENTRY("xhprof.sampling_interval", STRINGIFY(XHPROF_DEFAULT_SAMPLING_INTERVAL), PHP_INI_ALL, OnUpdateLong, sampling_interval, xhprof_global_t, xhprof_globals)
 
+/* sampling_depth:
+ * Depth to trace call-chain by the sampling profiler
+ */
+STD_PHP_INI_ENTRY("xhprof.sampling_depth", STRINGIFY(INT_MAX), PHP_INI_ALL, OnUpdateLong, sampling_depth, xhprof_global_t, xhprof_globals)
 PHP_INI_END()
 
 /* Init module */
@@ -221,6 +232,9 @@ PHP_MINIT_FUNCTION(xhprof)
     for (i = 0; i < 256; i++) {
         XHPROF_G(func_hash_counters[i]) = 0;
     }
+    if (XHPROF_G(sampling_interval) < XHPROF_MINIMAL_SAMPLING_INTERVAL) {
+        XHPROF_G(sampling_interval) = XHPROF_MINIMAL_SAMPLING_INTERVAL;
+    }
 
     /* Replace zend_compile with our proxy */
     _zend_compile_file = zend_compile_file;
@@ -769,7 +783,7 @@ void hp_sample_stack(hp_entry_t  **entries)
     snprintf(key, sizeof(key), "%d.%06d", XHPROF_G(last_sample_time).tv_sec, XHPROF_G(last_sample_time).tv_usec);
 
     /* Init stats in the global stats_count hashtable */
-    symbol = hp_get_function_stack(*entries, INT_MAX);
+    symbol = hp_get_function_stack(*entries, XHPROF_G(sampling_depth));
 
     add_assoc_string(&XHPROF_G(stats_count), key, symbol);
 
@@ -801,7 +815,7 @@ void hp_sample_check(hp_entry_t **entries)
         XHPROF_G(last_sample_tsc) += XHPROF_G(sampling_interval_tsc);
 
         /* bump last_sample_time - HAS TO BE UPDATED BEFORE calling hp_sample_stack */
-        incr_us_interval(&XHPROF_G(last_sample_time), XHPROF_SAMPLING_INTERVAL);
+        incr_us_interval(&XHPROF_G(last_sample_time), XHPROF_G(sample_interval));
 
         /* sample the stack */
         hp_sample_stack(entries);
@@ -946,10 +960,10 @@ void hp_mode_sampled_init_cb()
     /* Find the microseconds that need to be truncated */
     gettimeofday(&XHPROF_G(last_sample_time), 0);
     now = XHPROF_G(last_sample_time);
-    hp_trunc_time(&XHPROF_G(last_sample_time), XHPROF_SAMPLING_INTERVAL);
+    hp_trunc_time(&XHPROF_G(last_sample_time), XHPROF_G(sample_interval));
 
     /* Convert sampling interval to ticks */
-    XHPROF_G(sampling_interval_tsc) = XHPROF_SAMPLING_INTERVAL;
+    XHPROF_G(sampling_interval_tsc) = XHPROF_G(sample_interval);
 }