Hello there, I have an issue with some code running JavaScript under V8, The code runs in a *single* Isolate, that has *one* context. The context is created, populated with some scripts, the scripts are executed, and then the context is Exit()ed. The Isolate stays intact. The above sequence repeats itself several times, with the *same* scripts running time and again. This is what I call a series of "transactions".
What happens, is after the initial transaction is executed, all the subsequent ones experience a drastic slowdown (sometimes 7 times slower). I tried profiling the code with* oprofile*, and I see this picture: *Fast transaction:* PU: Intel Ivy Bridge microarchitecture, speed 3401 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 100000 samples % image name symbol name 2444 1.8590 libv8.so v8::internal::HandleScope::ZapRange(v8::internal::Object**, v8::internal::Object**) 1849 1.4064 libv8.so v8::internal::HeapObject::map() const 1537 1.1691 libv8.so v8::base::NoBarrier_Load(long const volatile*) 1417 1.0778 libv8.so v8::internal::SmiTagging<8ul>::SmiToInt(v8::internal::Object const*) 1286 0.9782 libv8.so v8::internal::FixedArrayBase::length() const 1273 0.9683 libpthread-2.13.so pthread_getspecific 1250 0.9508 libv8.so v8::internal::MapWord::MapWord(unsigned long) 1235 0.9394 libv8.so v8::internal::FixedArray::get(int) const 1171 0.8907 libv8.so v8::base::Acquire_Load(long const volatile*) 1029 0.7827 libv8.so void v8::base::CallOnce<void>(long*, v8::base::OneArgFunction<void*>::type, void*) 1021 0.7766 libv8.so v8::internal::HeapObject::map_word() const ..... *Slow transaction:* CPU: Intel Ivy Bridge microarchitecture, speed 3401 MHz (estimated) Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (No unit mask) count 100000 samples % image name symbol name 27474 8.4737 libv8.so v8::internal::HeapObject::map() const 17271 5.3268 libv8.so v8::internal::MapWord::MapWord(unsigned long) 15862 4.8923 libv8.so v8::internal::Map::instance_type() 14754 4.5505 libv8.so v8::base::NoBarrier_Load(long const volatile*) 13941 4.2998 libv8.so v8::internal::HeapObject::map_word() const 13573 4.1863 libv8.so v8::internal::MapWord::FromRawValue(unsigned long) 11299 3.4849 libv8.so v8::internal::Internals::HasHeapObjectTag(v8::internal::Object const*) 10365 3.1968 libv8.so v8::internal::Object::IsInternalizedString() const 8469 2.6121 libv8.so v8::internal::HeapObject::cast(v8::internal::Object const*) 8085 2.4936 libv8.so v8::internal::Object::IsHeapObject() const 6350 1.9585 libv8.so v8::internal::Object::IsOddball() const 6105 1.8829 libv8.so v8::internal::Embedded::Embedded() 5777 1.7818 libv8.so v8::internal::MapWord::ToRawValue() 5670 1.7488 libv8.so v8::internal::MapWord::ToMap() ... Any idea what is happening here? Why is the same code running so slowly the second (third, etc) time around? Regards, Danny -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
