Re: [PATCH v1] migration: using trace_ to replace DPRINTF

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 10/17/20 11:35 AM, Bihong Yu wrote:
> Signed-off-by: Bihong Yu <yubihong@huawei.com>
> ---
>   migration/block.c      | 36 ++++++++++++++++++------------------
>   migration/page_cache.c | 13 +++----------
>   migration/trace-events | 13 +++++++++++++
>   3 files changed, 34 insertions(+), 28 deletions(-)
...
> diff --git a/migration/trace-events b/migration/trace-events
> index 338f38b..772bb81 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -325,3 +325,16 @@ get_ramblock_vfn_hash(const char *idstr, uint64_t vfn, uint32_t crc) "ramblock n
>   calc_page_dirty_rate(const char *idstr, uint32_t new_crc, uint32_t old_crc) "ramblock name: %s, new crc: %" PRIu32 ", old crc: %" PRIu32
>   skip_sample_ramblock(const char *idstr, uint64_t ramblock_size) "ramblock name: %s, ramblock size: %" PRIu64
>   find_page_matched(const char *idstr) "ramblock %s addr or size changed"
> +
> +# block.c
> +init_blk_migration_shared(const char *blk_device_name) "Start migration for %s with shared base image"
> +init_blk_migration_full(const char *blk_device_name) "Start full migration for %s"
> +mig_save_device_dirty(int64_t sector) "Error reading sector %" PRId64
> +flush_blks(const char *action, int submitted, int read_done, int transferred) "%s submitted %d read_done %d transferred %d"
> +block_save(const char *mig_stage, int submitted, int transferred) "Enter save live %s submitted %d transferred %d"
> +block_save_complete(void) "Block migration completed"
> +block_save_pending(uint64_t pending) "Enter save live pending  %" PRIu64
> +
> +# page_cache.c
> +cache_init(int64_t max_num_items) "Setting cache buckets to %" PRId64
> +cache_insert(void) "Error allocating page"

The patch is good, but I strongly recommend to have trace events
starting with the subsystem prefix (here migration). So we can
keep using the 'block*' rule to match all events from the block
subsystem, without including the migration events.

Thanks,

Phil.