[SPDK] Set SPDK log level and log flags

Hi

Looking at SPDK log related command options in scripts/rpc.py,  I see the following command options

    log_set_flag (set_log_flag)

                        set log flag

    log_clear_flag (clear_log_flag)

                        clear log flag

    log_get_flags (get_log_flags)

                        get log flags

    log_set_level (set_log_level)

                        set log level

    log_get_level (get_log_level)

                        get log level

    log_set_print_level (set_log_print_level)

                        set log print level

    log_get_print_level (get_log_print_level)

                        get log print level

Running log_get_flags, I see the following log flags:

~/spdk/spdk$ sudo scripts/rpc.py log_get_flags

{

  "aio": false,

  "app_config": false,

  "bdev": false,

  "bdev_ftl": false,

  "bdev_malloc": false,

  "bdev_null": false,

  "bdev_nvme": false,

  "bdev_ocssd": false,

  "bdev_raid": false,

  "bdev_raid0": false,

  "blob": false,

  "blob_rw": false,

  "blobfs": false,

  "blobfs_rw": false,

  "copy_ioat": false,

  "ftl_core": false,

  "ftl_init": false,

  "gpt_parse": false,

  "ioat": false,

  "json_util": false,

  "log": false,

  "lvol": false,

  "lvolrpc": false,

  "nbd": false,

  "net": false,

  "notify_rpc": false,

  "nvme": false,

  "nvmf": false,

  "nvmf_tcp": false,

  "opal": false,

  "raidrpc": false,

  "reactor": false,

  "rpc": false,

  "rpc_client": false,

  "thread": false,

  "trace": false,

  "vbdev_delay": false,

  "vbdev_gpt": false,

  "vbdev_lvol": false,

  "vbdev_opal": false,

  "vbdev_passthru": false,

  "vbdev_split": false,

  "vbdev_zone_block": false,

  "virtio": false,

  "virtio_blk": false,

  "virtio_dev": false,

  "virtio_pci": false,

  "virtio_user": false,

  "vmd": false

}

What are the relationship between log level, log print level and log flags. How do I use them? I tried to change log level and log print level from “NOTICE” to “DEBUG” but did not see any change. Also to use them, do I need to make any special SPDK build?

Thanks,
-Wenhua Liu