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Date: Fri, 3 Oct 2025 09:32:57 +0200
From: Christoph Hellwig <hch@lst.de>
To: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>, Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-trace-kernel@vger.kernel.org, linux-btrace@vger.kernel.org,
	John Garry <john.g.garry@oracle.com>,
	Hannes Reinecke <hare@suse.de>, Damien Le Moal <dlemoal@kernel.org>,
	Christoph Hellwig <hch@lst.de>, Naohiro Aota <naohiro.aota@wdc.com>,
	Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>,
	Chaitanya Kulkarni <chaitanyak@nvidia.com>,
	"Martin K . Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH v2 11/15] blktrace: add block trace commands for zone
 operations
Message-ID: <20251003073257.GE12624@lst.de>
References: <20250925150231.67342-1-johannes.thumshirn@wdc.com> <20250925150231.67342-12-johannes.thumshirn@wdc.com>
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User-Agent: Mutt/1.5.17 (2007-11-01)

On Thu, Sep 25, 2025 at 05:02:27PM +0200, Johannes Thumshirn wrote:
> Add block trace commands for zone operations. These are added as a
> separate set of 'block trace commands' shifted by 32bit so that they do
> not interfere with the old 16bit wide trace command field in 'struct
> blk_io_trace' action.

Can you explain how the commands are handled for old/new here?

Because I'd still much prefer to sort things out so that they make
sense for the new code if possible.  i.e. have a 32-bit command
and 32 bit flags, and use sensible encoding for the new one, and
remap the supported once to the old organically grown one.