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jeplerjepler
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run_background_tasks: Do nothing unless there has been a tick
This improves performance of running python code by 34%, based on the "pystone" benchmark on metro m4 express at 5000 passes (1127.65 -> 1521.6 passes/second). In addition, by instrumenting the tick function and monitoring on an oscilloscope, the time actually spent in run_background_tasks() on the metro m4 decreases from average 43% to 0.5%. (however, there's some additional overhead that is moved around and not accounted for in that "0.5%" figure, each time supervisor_run_background_tasks_if_tick is called but no tick has occurred) On the CPB, it increases pystone from 633 to 769, a smaller percentage increase of 21%. I did not measure the time actually spent in run_background_tasks() on CPB. Testing performed: on metro m4 and cpb, run pystone adapted from python3.4 (change time.time to time.monotonic for sub-second resolution) Besides running a 5000 pass test, I also ran a 50-pass test while scoping how long an output pin was set. Average: 34.59ms or 1445/s on m4, 67.61ms or 739/s on cbp, both matching the other pystone result reasonably well. import pystone import board import digitalio import time d = digitalio.DigitalInOut(board.D13) d.direction = digitalio.Direction.OUTPUT while True: d.value = 0 time.sleep(.01) d.value = 1 pystone.main(50)
1 parent 40a47d4 commit 568636d

3 files changed

Lines changed: 15 additions & 2 deletions

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‎py/circuitpy_mpconfig.h‎

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@@ -653,8 +653,8 @@ extern const struct _mp_obj_module_t ustack_module;
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FLASH_ROOT_POINTERS \
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NETWORK_ROOT_POINTERS \
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void run_background_tasks(void);
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#define RUN_BACKGROUND_TASKS (run_background_tasks())
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void supervisor_run_background_tasks_if_tick(void);
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#define RUN_BACKGROUND_TASKS (supervisor_run_background_tasks_if_tick())
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// TODO: Used in wiznet5k driver, but may not be needed in the long run.
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#define MICROPY_THREAD_YIELD()

‎supervisor/shared/tick.c‎

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@@ -24,10 +24,13 @@
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* THE SOFTWARE.
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*/
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#include <stdatomic.h>
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#include "supervisor/shared/tick.h"
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#include "supervisor/filesystem.h"
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#include "supervisor/shared/autoreload.h"
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static atomic_bool tick_up;
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static volatile uint64_t ticks_ms;
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#if CIRCUITPY_GAMEPAD
@@ -44,6 +47,7 @@ void supervisor_tick(void) {
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ticks_ms ++;
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atomic_store(&tick_up, true);
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#if CIRCUITPY_FILESYSTEM_FLUSH_INTERVAL_MS > 0
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filesystem_tick();
@@ -74,3 +78,11 @@ uint64_t supervisor_ticks_ms64() {
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uint32_t supervisor_ticks_ms32() {
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return ticks_ms;
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}
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extern void run_background_tasks(void);
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void supervisor_run_background_tasks_if_tick() {
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if (atomic_exchange(&tick_up, false)) {
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run_background_tasks();
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}
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}

‎supervisor/shared/tick.h‎

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@@ -33,5 +33,6 @@
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extern void supervisor_tick(void);
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extern uint32_t supervisor_ticks_ms32(void);
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extern uint64_t supervisor_ticks_ms64(void);
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extern void supervisor_run_background_if_tick(void);
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#endif

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