FreeRtos slow?

[brp80000]

Can I see an example of this code?
I'll have to use an interrupt when the DMA data is received to process it immediately. And this again will conflict with flash recording.

[brp80000]

• void i2s_init()
  {
  i2s_config_t i2s_config = {
  .mode = I2S_MODE_MASTER | I2S_MODE_RX | I2S_MODE_TX | I2S_MODE_ADC_BUILT_IN,
  .sample_rate = 32000, // i2s sample rate
  .bits_per_sample = 32, // i2s data bits
  .communication_format = I2S_COMM_FORMAT_I2S_MSB,
  .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT, //I2S data format
  .intr_alloc_flags = 0,
  .dma_buf_count = 2,
  .dma_buf_len = 64
  };
  //install and start i2s driver
  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  //init ADC pad
  i2s_set_adc_mode(ADC_UNIT_1, ADC1_CHANNEL_0 | ADC1_CHANNEL_3);
  i2s_adc_enable(I2S_NUM_0); // i2s number
  }

This is my configuration of ADC1 and DMA
How further can I read and process data in DMA?

[brp80000]

Can I poll all four ADC channels in DMA?

[brp80000]

I realized that it is impossible to poll 4 channels of ADC via DMA.

I have configured a timer interrupt 1000 times per second and am using xSemaphoreGiveFromISR().
Then xSemaphoreTake() triggers the highest priority task to capture data (as short as possible with a minimum of calculations). Basic calculations and saving to flash 20 times per second is performed in a low-priority task.
Strange result I'm missing about 10% of the interrupts. So expected 1000 lines in the log should be recorded in 50 seconds, but it takes 54.7 seconds to gettimeofday() in my log.