To enable the profiler, set :c:macro:`LV_USE_PROFILER` in ``lv_conf.h`` and configure the following options:
1. Enable the built-in profiler functionality by setting :c:macro:`LV_USE_PROFILER_BUILTIN`.
2. Buffer configuration: Set the value of :c:macro:`LV_PROFILER_BUILTIN_BUF_SIZE` to configure the buffer size. A larger buffer can store more trace event information, reducing interference with rendering. However, it also results in higher memory consumption.
3. Timestamp configuration: LVGL uses the :cpp:func:`lv_tick_get` function with a precision of 1ms by default to obtain timestamps when events occur. Therefore, it cannot accurately measure intervals below 1ms. If your system environment can provide higher precision (e.g., 1us), you can configure the profiler as follows:
- Recommended configuration in **UNIX** environments:
..code:: c
#include <time.h>
static uint32_t my_get_tick_us_cb(void)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000000 + ts.tv_nsec / 1000;
}
void my_profiler_init(void)
{
lv_profiler_builtin_config_t config;
lv_profiler_builtin_config_init(&config);
config.tick_per_sec = 1000000; /* One second is equal to 1000000 microseconds */
config.tick_get_cb = my_get_tick_us_cb;
lv_profiler_builtin_init(&config);
}
- Recommended configuration in **Arduino** environments:
..code:: c
void my_profiler_init(void)
{
lv_profiler_builtin_config_t config;
lv_profiler_builtin_config_init(&config);
config.tick_per_sec = 1000000; /* One second is equal to 1000000 microseconds */
config.tick_get_cb = micros; /* Use the microsecond time stamp provided by Arduino */
lv_profiler_builtin_init(&config);
}
4. Log output configuration: LVGL uses the :cpp:func:`LV_LOG` interface by default to output trace information. If you want to use another interface to output log information (e.g., file stream), you can redirect the log output using the following code:
..code:: c
static void my_log_print_cb(const char * buf)
{
printf("%s", buf);
}
void my_profiler_init(void)
{
lv_profiler_builtin_config_t config;
lv_profiler_builtin_config_init(&config);
... /* other configurations */
config.flush_cb = my_log_print_cb;
lv_profiler_builtin_init(&config);
}
Run the test scenario
^^^^^^^^^^^^^^^^^^^^^
Run the UI scenario that you want to measure, such as scrolling a scrollable page up and down or entering/exiting an application.
Process the logs
^^^^^^^^^^^^^^^^
Save the output log as `my_trace.txt`, use `trace_filter.py` for filtering and preprocessing:
Please check the completeness of the logs. If the logs are incomplete, it may be due to the following reasons:
1. Serial port reception errors caused by a high baud rate. You need to reduce the baud rate.
2. Data corruption caused by other thread logs inserted during the printing of trace logs. You need to disable the log output of other threads or refer to the configuration above to use a separate log output interface.
3. Cross-thread calling of :c:macro:`LV_PROFILER_BEGIN/END`.The built-in LVGL profiler is designed for single-threaded use, so calling it from multiple threads can lead to thread safety issues. If you need to use it in a multi-threaded environment, you can use profiler interfaces provided by your operating system that ensure thread safety.
4. Make sure that the string passed in by c:macro:`LV_PROFILER_BEGIN_TAG/END_TAG` is not a local variable on the stack or a string in shared memory, because currently only the string address is recorded and the content is not copied.
If the function execution time is lower than the precision of the timestamps, this situation can occur. You can refer to the configuration instructions above to use a higher precision timestamp.
Significant stuttering occurs during profiling
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
When the buffer used to store trace events becomes full, the profiler will output all the data in the buffer, which can cause UI blocking and stuttering during the output. You can optimize this by taking the following measures:
1. Increase the value of :c:macro:`LV_PROFILER_BUILTIN_BUF_SIZE`. A larger buffer can reduce the frequency of log printing, but it also consumes more memory.
2. Optimize the execution time of log printing functions, such as increasing the serial port baud rate or improving file writing speed.
Trace logs are not being output
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
If the trace logs are not automatically printed when the buffer is not full, you can try the following methods to force the log output:
1. Reduce the value of :c:macro:`LV_PROFILER_BUILTIN_BUF_SIZE` to fill the buffer more quickly and trigger automatic printing.
2. Manually call or use a timer to call the :cpp:func:`lv_profiler_builtin_flush` function to force the log output.
