J-Link RTT Viewer lost some logs

[Leo2019]

The Jlink RTT Viewer can't output the message one by one , some was lost , what is the problem?  (Jink connect by SWD 4000khz)

[Jørgen Holmefjord]

Hi,

Are you using NRF_LOG to output logs to RTT? Which SDK version are you using? There are some configs in sdk_config.h related to NRF_LOG and RTT buffer sizes, and behavior with buffer overflow. Do you send large amounts of logs in short time?

Best regards,
Jørgen

[Leo2019]

Yes,I using NRF_LOG_INFO to output logs to RTT  in SDK 15.0  .

In sdk_config.h, I had set  

#define SEGGER_RTT_CONFIG_BUFFER_SIZE_UP 2048 ;

#define NRF_LOG_BUFSIZE 2048

#define NRF_LOG_MSGPOOL_ELEMENT_COUNT 18

I send about  20-40  lines logs on startup，some was lost

[Jørgen Holmefjord]

Can you try setting SEGGER_RTT_CONFIG_DEFAULT_MODE to 2 (BLOCK_IF_FIFO_FULL)?