Block IO Tracing
----------------

Written by Jens Axboe <axboe@suse.de> (initial version and kernel support) and
Alan D. Brunelle (threading and splitup into two seperate programs).


Requirements
------------

Currently, the kernel support patch isn't merged yet. The last posted patch
is:

http://marc.theaimsgroup.com/?l=linux-kernel&m=112487579802074&w=2

and applies against 2.6.13-rc6-mm2. The patch is also included in the git
repository you pulled to get this file:

rsync://rsync.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git

Additionally, you need to apply the relayfs-read update patch also located
in the kernel/ directory.


Usage
-----

To run:
	% blktrace -d <dev> [-a <trace> [-a <trace>]]
		-a <trace> is one of: (use multiple -a options to get more)
			READ
			WRITE
			BARRIER
			SYNC
			QUEUE
			REQUEUE
			ISSUE
			COMPLETE
			FS
			PC
	--- run task to generate load to be traced ---
	<SIGINT to kill>
	--- Generates:
		<dev>_dat.[0..ncpus] : Contains binary pdu data
		<dev>_out.[0..ncpus] : Contains binary trace data

	% blkparse <dev>
	--- Generates:
		<dev>_log.[0..ncpus] : Contains formatted trace data
		Merged formatted trace data to stdout


20050826, Jens Axboe <axboe@suse.de>