This adds a new tracepoint for the target to trace async event. This is
helpful in debugging and comparing host and target side async events
especially when host is connected to different targets on different
machines and now that we rely on userspace components to generate AEN.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This patch introduces target-side request tracing. As Christoph
suggested, the trace would not be in a core or module to avoid
disadvantages like cache miss:
http://lists.infradead.org/pipermail/linux-nvme/2019-June/024721.html
The target-side trace code is entirely based on the Johannes's trace code
from the host side. It has lots of codes duplicated, but it would be
better than having advantages mentioned above.
It also traces not only fabrics commands, but also nvme normal commands.
Once the codes to be shared gets bigger, then we can make it common as
suggsted.
This also removed the create_sq and create_cq trace parsing functions
because it will be done by the connect fabrics command.
Example:
echo 1 > /sys/kernel/debug/tracing/event/nvmet/nvmet_req_init/enable
echo 1 > /sys/kernel/debug/tracing/event/nvmet/nvmet_req_complete/enable
cat /sys/kernel/debug/tracing/trace
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
[hch: fixed the symbol namespace and a an endianess conversion]
Signed-off-by: Christoph Hellwig <hch@lst.de>