Hi;
Hilary Cheng wrote:
> What do u think the critical part that makes JJOS slow ? :O
How much time do you have? ;=)
Seriously, since you asked, in no particular order (based upon a cursory
examination of profiling output)...
(1) Obligation to "intercept" method calls to Sun's JDK for methods that will
break decaf+jjos. Entails examining each and every method call to see if it is
one such. This should go away when we use classpath.
(2) Failure to do "invoke" opcode rewriting so that we can avoid overhead of
method lookup.
(3) Failure to inline "obvious" candidates (e.g., all the local_variable
accessor and mutators methods, some constructors).
(4) Scheduler/interrupt polling overhead is way too high...
(5) Given that the heap implementation zeroes memory, some common constructors
(e.g., java_object) could skip re-initializing member variables...
(6) Failure to do JIT compilation...
BTW, here are the top couple of offenders for the host build WITHOUT
optimization:
> % cumulative self self total
> time seconds seconds calls ms/call ms/call name
> 9.92 5.95 5.95 2336461 0.00 0.01 frame::runOpcode(java_object &)
> 9.20 11.47 5.52 2334752 0.00 0.00
>jjMachine::interruptFIFOEmpty(void)
> 3.67 13.67 2.20 1 2200.00 58806.54 scheduler::start(jjMachine *,
>java_class *)
> 3.60 15.83 2.16 2334752 0.00 0.00
>scheduler::notifyOfInterrupts(jjMachine *, java_class *)
> 3.32 17.82 1.99 2350034 0.00 0.00
>java_object::java_object(java_class *)
> 3.25 19.77 1.95 2334752 0.00 0.00
>scheduler::currentTimeSliceExpired(void)
> 2.98 21.56 1.79 2336461 0.00 0.01 java_thread::runOpcode(void)
> 2.85 23.27 1.71 910386 0.00 0.00
>local_variables::load_jint(unsigned int)
> 2.80 24.95 1.68 4678122 0.00 0.00 scheduler::currentThread(void)
> 2.80 26.63 1.68 2354659 0.00 0.00 typed_data::~typed_data(void)
> 2.57 28.17 1.54 456252 0.00 0.00 jbSLL<java_thread
>*>::_lookup(jbSLLItem<java_thread *> *, java_thread *const &)
> 2.55 29.70 1.53 2337693 0.00 0.00 d_stack<frame>::peek(void)
> 2.48 31.19 1.49 2350238 0.00 0.00 threadable::threadable(void)
> 2.35 32.60 1.41 2336461 0.00 0.00 java_object::~java_object(void)
> 2.25 33.95 1.35 388818 0.00 0.00 wcscmp(unsigned short const *,
>unsigned short const *)
> 2.02 35.16 1.21 1113591 0.00 0.00 operand_stack::pop_jint(void)
> 1.98 36.35 1.19 2336461 0.00 0.00
>java_thread::currentFrame(void) const
> 1.95 37.52 1.17 1 1170.00 1170.00 jbHeap::scrubMemory(void)
> 1.73 38.56 1.04 2393897 0.00 0.00 typed_data::typed_data(void)
> 1.72 39.59 1.03 1189224 0.00 0.00
>s_stack<java_word>::push(java_word)
> 1.70 40.61 1.02 2024179 0.00 0.00 java_word::operator int(void)
>const
> 1.53 41.53 0.92 984558 0.00 0.00
>operand_stack::push_java_word(java_word)
> 1.32 42.32 0.79 361580 0.00 0.01 frame::if_icmplt(java_object &)
> 1.25 43.07 0.75 2334752 0.00 0.00 java_thread::priority(void)
> 1.17 43.77 0.70 1189224 0.00 0.00 s_stack<java_word>::pop(void)
> 1.15 44.46 0.69 364244 0.00 0.00 frame::bipush(java_object &)
> 1.15 45.15 0.69 78375 0.01 0.01
>jbZipFileLocalFileHeader::getMyFileName(char *)
> 1.07 45.79 0.64 4700476 0.00 0.00 thread_list::thread_list(void)
> 1.05 46.42 0.63 2854961 0.00 0.00 heapMark(void *)
> 1.05 47.05 0.63 2334753 0.00 0.00
>scheduler::noThreadsLeftToRun(void)
> 1.00 47.65 0.60 50290 0.01 0.04 heapMarkBlock(void *, void *)
> 0.98 48.24 0.59 78375 0.01 0.01
>jbZipFileLocalFileHeader::isValidZipFile(void)
> 0.97 48.82 0.58 362498 0.00 0.01 frame::iinc(java_object &)
Here are the top couple of offenders for the -O3 (max optimization) host build:
> % cumulative self self total
> time seconds seconds calls ms/call ms/call name
> 12.49 5.68 5.68 2336461 0.00 0.01 frame::runOpcode(java_object &)
> 11.26 10.80 5.12 2334752 0.00 0.00
>jjMachine::interruptFIFOEmpty(void)
> 7.48 14.20 3.40 2338911 0.00 0.00
>java_object::java_object(java_class *)
> 7.06 17.41 3.21 1 3210.00 44877.76 scheduler::start(jjMachine *,
>java_class *)
> 5.02 19.69 2.28 2334752 0.00 0.00 java_thread::priority(void)
> 4.95 21.94 2.25 2337693 0.00 0.00 d_stack<frame>::peek(void)
> 4.95 24.19 2.25 2334753 0.00 0.00 jbSLL<java_thread
>*>::isEmpty(void)
> 4.60 26.28 2.09 2336461 0.00 0.00 java_thread::runOpcode(void)
> 3.50 27.87 1.59 2350238 0.00 0.00 threadable::threadable(void)
> 2.75 29.12 1.25 910386 0.00 0.00
>local_variables::load_jint(unsigned int)
> 2.33 30.18 1.06 1113591 0.00 0.00 operand_stack::pop_jint(void)
> 2.11 31.14 0.96 2354659 0.00 0.00 typed_data::~typed_data(void)
> 1.67 31.90 0.76 2024179 0.00 0.00 java_word::operator int(void)
>const
> 1.65 32.65 0.75 1189224 0.00 0.00 s_stack<java_word>::pop(void)
> 1.61 33.38 0.73 456252 0.00 0.00 jbSLL<java_thread
>*>::lookup(java_thread *const &)
> 1.58 34.10 0.72 388818 0.00 0.00 wcscmp(unsigned short const *,
>unsigned short const *)
> 1.56 34.81 0.71 4700476 0.00 0.00 thread_list::thread_list(void)
> 1.50 35.49 0.68 78375 0.01 0.01
>jbZipFileLocalFileHeader::isValidZipFile(void)
> 1.36 36.11 0.62 1189224 0.00 0.00
>s_stack<java_word>::push(java_word)
> 1.34 36.72 0.61 968658 0.00 0.00
>operand_stack::push_java_word(java_word)
> 1.25 37.29 0.57 1 570.00 570.00 jbHeap::scrubMemory(void)
> 1.23 37.85 0.56 456252 0.00 0.00
>scheduler::switchToNextThread(void)
> 1.08 38.34 0.49 51002 0.01 0.02 my_calloc(unsigned int,
>unsigned int)
> 0.97 38.78 0.44 3152254 0.00 0.00 pagerDescriptorForPage(pager
>*, void *)
> 0.95 39.21 0.43 1658416 0.00 0.00 java_word::operator=(java_word
>const &)
-jm
--
==== John Morrison ==== MaK Technologies, Inc.
==== Chief Technology Officer ==== 185 Alewife Brook Pkwy, Cambridge, MA 02138
==== [EMAIL PROTECTED] ==== http://www.mak.com/
==== vox:617-876-8085 x115 ==== fax:617-876-9208
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