x86: use =A as output for RDTSC on x86-32
The timing_info benchmark on qemu_x86 shows this is a bit faster.
Before:
START - Time Measurement
Timing results: Clock frequency: 1000 MHz
Context switch : 896 cycles , 895 ns
Interrupt latency : 768 cycles , 767 ns
Tick overhead :14912 cycles , 14911 ns
Thread creation :18688 cycles , 18687 ns
Thread abort (non-running) :49216 cycles , 49215 ns
Thread abort (_current) :55616 cycles , 55615 ns
Thread suspend :11072 cycles , 11071 ns
Thread resume :10272 cycles , 10271 ns
Thread yield :12213 cycles , 12212 ns
Thread sleep :17984 cycles , 17983 ns
Heap malloc :21702 cycles , 21701 ns
Heap free :15176 cycles , 15175 ns
Semaphore take with context switch :19168 cycles , 19167 ns
Semaphore give with context switch :18400 cycles , 18399 ns
Semaphore take without context switch :2208 cycles , 2207 ns
Semaphore give without context switch :4704 cycles , 4703 ns
Mutex lock :1952 cycles , 1951 ns
Mutex unlock :7936 cycles , 7935 ns
Message queue put with context switch :20320 cycles , 20319 ns
Message queue put without context switch :5792 cycles , 5791 ns
Message queue get with context switch :22112 cycles , 22111 ns
Message queue get without context switch :5312 cycles , 5311 ns
Mailbox synchronous put :27936 cycles , 27935 ns
Mailbox synchronous get :23392 cycles , 23391 ns
Mailbox asynchronous put :11808 cycles , 11807 ns
Mailbox get without context switch :20416 cycles , 20415 ns
Drop to user mode :643712 cycles , 643711 ns
User thread creation :652096 cycles , 652095 ns
Syscall overhead :2720 cycles , 2719 ns
Validation overhead k_object init :4256 cycles , 4255 ns
Validation overhead k_object permission :4224 cycles , 4223 ns
Time Measurement finished
After:
START - Time Measurement
Timing results: Clock frequency: 1000 MHz
Context switch : 896 cycles , 895 ns
Interrupt latency : 768 cycles , 767 ns
Tick overhead :14752 cycles , 14751 ns
Thread creation :18464 cycles , 18463 ns
Thread abort (non-running) :48992 cycles , 48991 ns
Thread abort (_current) :55552 cycles , 55551 ns
Thread suspend :10848 cycles , 10847 ns
Thread resume :10048 cycles , 10047 ns
Thread yield :12213 cycles , 12212 ns
Thread sleep :17984 cycles , 17983 ns
Heap malloc :21702 cycles , 21701 ns
Heap free :15176 cycles , 15175 ns
Semaphore take with context switch :19104 cycles , 19103 ns
Semaphore give with context switch :18368 cycles , 18367 ns
Semaphore take without context switch :1984 cycles , 1983 ns
Semaphore give without context switch :4480 cycles , 4479 ns
Mutex lock :1728 cycles , 1727 ns
Mutex unlock :7712 cycles , 7711 ns
Message queue put with context switch :20224 cycles , 20223 ns
Message queue put without context switch :5568 cycles , 5567 ns
Message queue get with context switch :22016 cycles , 22015 ns
Message queue get without context switch :5088 cycles , 5087 ns
Mailbox synchronous put :27840 cycles , 27839 ns
Mailbox synchronous get :23296 cycles , 23295 ns
Mailbox asynchronous put :11584 cycles , 11583 ns
Mailbox get without context switch :20192 cycles , 20191 ns
Drop to user mode :643616 cycles , 643615 ns
User thread creation :651872 cycles , 651871 ns
Syscall overhead :2464 cycles , 2463 ns
Validation overhead k_object init :4032 cycles , 4031 ns
Validation overhead k_object permission :4000 cycles , 3999 ns
Time Measurement finished
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
80fb6538b3