Re: [PATCH 12/12] iomap: add tracing for the address space operations

[Dave Chinner]

On Mon, Jun 24, 2019 at 07:52:53AM +0200, Christoph Hellwig wrote:
> Lift the xfs code for tracing address space operations to the iomap
> layer.
> 
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

....

> diff --git a/include/trace/events/iomap.h b/include/trace/events/iomap.h
> new file mode 100644
> index 000000000000..da50ece663f8
> --- /dev/null
> +++ b/include/trace/events/iomap.h
> @@ -0,0 +1,82 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2009-2019, Christoph Hellwig
> + * All Rights Reserved.
> + */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM iomap

Can you add a comment somewhere here that says these tracepoints are
volatile and we reserve the right to change them at any time so they
don't form any sort of persistent UAPI that we have to maintain?

-Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx