Implement resource-saving mode of Profiler.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index 5a4a3c86d1b4bc8f2416ee3c510e0b53d794c307..13e41e34fefaa3e87bec136daa759c1cdd93743d 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -336,6 +336,9 @@ DEFINE_bool(prof, false,
             "Log statistical profiling information (implies --log-code).")
 DEFINE_bool(prof_auto, true,
             "Used with --prof, starts profiling automatically")

[Søren Thygesen Gjesse, 2009/05/25 07:09:15]

Do we need both --prof-auto and --prof-lazy. With your last change where logging
can be initiated by getting all the functions in the heap I don't see a reason
for logging and sampling if not really profiling. Am I missing something here?
If it makes sense to consolidate --prof-auto and --prof-lazy in some way you can
do that in a new change.

[Mikhail Naganov, 2009/05/25 08:23:43]

Currently, we have several differences in results of "traditional" compiler / gc
logging vs. heap traversal, the differences can be seen in the code of
"AreFuncNamesEqual" and "AreEntitiesEqual" functions from test-log.cc. They only
related to native and internal code, so they are irrelevant to web app
developers, but may make sense for V8 developers. That's why I'll prefer to
leave "traditional" profiling logging for some time until I figure out how to
handle this better.

+DEFINE_bool(prof_lazy, false,
+            "Used with --prof, only does sampling and logging"
+            " when profiler is active (implies --noprof_auto).")
 DEFINE_bool(log_regexp, false, "Log regular expression execution.")
 DEFINE_bool(sliding_state_window, false,
             "Update sliding state window counters.")