In SDK 15.1.0 NRF_LOG_STR_PUSH_BUFFER_SIZE is defined twice in every sdk_config.h in the SDK. For example in the ble_app_template/pca10040/s132/config/sdk_config.h:
// <o> NRF_LOG_STR_PUSH_BUFFER_SIZE - Size of the buffer dedicated for strings stored using @ref NRF_LOG_PUSH. // <16=> 16 // <32=> 32 // <64=> 64 // <128=> 128 // <256=> 256 // <512=> 512 // <1024=> 1024 #ifndef NRF_LOG_STR_PUSH_BUFFER_SIZE #define NRF_LOG_STR_PUSH_BUFFER_SIZE 128 #endif // <o> NRF_LOG_STR_PUSH_BUFFER_SIZE - Size of the buffer dedicated for strings stored using @ref NRF_LOG_PUSH. // <16=> 16 // <32=> 32 // <64=> 64 // <128=> 128 // <256=> 256 // <512=> 512 // <1024=> 1024 #ifndef NRF_LOG_STR_PUSH_BUFFER_SIZE #define NRF_LOG_STR_PUSH_BUFFER_SIZE 128 #endif