opjitconv runs indefinitely

Hi,

I found opjitconv ran indefinitely when profiling a Java application
running on
OpenJDK/ppc64le.  This is because OpenJDK sometimes reports generation of
zero-size jitted code via JVMTI, but scan_overlaps() in opjitconv does not
assume
the existence of jitted code with size zero.

(1) scan_overlaps() finds overlap between a normal jitted code and a
zero-size
     jitted code.
(2) eliminate_overlaps() tries to split the zero-size jitted code but
cannot.
(3) resolve_overlaps() incorrectly thinks the split has happened and invokes
     scan_overlaps() again.
(4) Back to (1)

One workaround would be to remove all the zero-size entries before resolving
overlaps (patch attached), but I am not sure if this is a good solution.
It works at least in my environment.


Regards,
Rei Odaira


--- oprofile-1.0.0/opjitconv/jitsymbol.c 2014-09-12 09:39:47.000000000 -0500
+++ oprofile-1.0.0-openjdk8-src/opjitconv/jitsymbol.c 2015-05-05
13:37:13.931202002 -0500
@@ -201,6 +201,26 @@
  }
 }

+static void invalidate_zero_size_entries(void)
+{
+ u32 i;
+ int flag;
+ struct jitentry * a;
+
+ flag = 0;
+ for (i = 0; i < entry_count; i++) {
+ a = entries_address_ascending[i];
+ if (a->code_size == 0) {
+ invalidate_entry(a);
+ flag = 1;
+ }
+ }
+ if (flag) {
+ resort_address();
+ resort_symbol();
+ }
+}
+

 /* select the symbol with the longest life time in the index range */
 static int select_one(int start_idx, int end_idx)
@@ -505,6 +525,7 @@
  int cnt = 0;

  invalidate_earlybirds(start_time);
+ invalidate_zero_size_entries();
  while ((rc = scan_overlaps()) && rc != OP_JIT_CONV_FAIL) {
  resort_address();
  if (cnt == 0) {

------------------------------------------------------------------------------
One dashboard for servers and applications across Physical-Virtual-Cloud 
Widest out-of-the-box monitoring support with 50+ applications
Performance metrics, stats and reports that give you Actionable Insights
Deep dive visibility with transaction tracing using APM Insight.
http://ad.doubleclick.net/ddm/clk/290420510;117567292;y

_______________________________________________
oprofile-list mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/oprofile-list