Lines Matching defs:blktrace
21 \title{blktrace User Guide}
22 \author{blktrace: Jens Axboe (jens.axboe@oracle.com)\\
31 blktrace is a block layer IO tracing mechanism which provides detailed
39 you don't need to patch blktrace support as it is already included.
41 \item[blktrace] A utility which transfers event traces from the kernel
46 run in \emph{live} mode directly outputs data collected by blktrace.
49 \subsection{blktrace Download Area}
51 The blktrace and blkparse utilities and associated kernel patch are provided
54 git://git.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git bt
60 blktrace. Some of the specific instructions below may need to be tailored
63 \subsection{\label{sec:get-blktrace}Retrieving blktrace}
65 As noted above, the kernel patch along with the blktrace and blkparse utilities are stored in a git repository. One simple way to get going would be:
68 % git clone git://git.kernel.org/pub/scm/linux/kernel/git/axboe/blktrace.git bt
109 blktrace utilizes files under the debug file system, and thus must have
136 \subsection{\label{sec:live-blktrace}blktrace -- live}
142 % blktrace -d /dev/sda -o - | blkparse -i -
197 \subsection{\label{sec:pc-blktrace}blktrace -- SCSI commands}
199 The previous section showed typical file system io actions, but blktrace
220 \subsection{\label{sec:blktrace-post}blktrace -- post-processing}
222 Another way to run blktrace is to have blktrace save data away for later
234 % blktrace /dev/sdaa /dev/sdc /dev/sdo &
333 \newpage\section{\label{sec:blktrace-ug}blktrace User Guide}
335 The \emph{blktrace} utility extracts event traces from the kernel (via
337 concerning the run-time behaviour of blktrace will help to understand some
341 \item blktrace receives data from the kernel in buffers passed up
347 \item blktrace defaults to collecting \emph{all} events that can be
359 \item blktrace stores the extracted data into files stored in the
361 \emph{device}.blktrace.\emph{cpu}, where \emph{device} is the base
368 \item blktrace may also be run concurrently with blkparse to produce
369 \emph{live} output -- to do this specify \emph{-o -} for blktrace.
371 \item The default behaviour for blktrace is to run forever until explicitly killed by the user (via a control-C, or \emph{kill} utility invocation). There are two ways to modify this:
374 \item You may utilize the blktrace utility itself to \emph{kill}
377 \item You can specify a run-time duration for blktrace via the
378 \emph{-w} option -- then blktrace will run for the specified number
383 \subsection{\label{sec:blktrace-args}Command line arguments}
420 blktrace disguingishes between two types of block layer requests,
428 commands. blktrace sends the command data block as a payload
436 the event information. As with blktrace, some details concerning blkparse
442 of blktrace, and blkparse is combining event streams and dumping
446 blktrace by specifying \emph{-i -} to blkparse, and combining it with
447 the live option for blktrace. An example would be:
450 % blktrace -d /dev/sda -o - | blkparse -i -
456 \item If you have saved event traces in blktrace with different output
457 names (via the \emph{-o} option to blktrace), you must specify the
475 -i \emph{file} & --input=\emph{file} & Specifies base name for input files -- default is \emph{device}.blktrace.\emph{cpu}. \\
476 & & As noted above, specifying \emph{-i -} runs in \emph{live} mode with blktrace \\
736 \newpage\section*{\label{sec:blktrace-kg}Appendix: blktrace Kernel Guide}
738 The blktrace facility provides an efficient event transfer mechanism which
741 blktrace utilizes in the kernel to effect this. It is good background data
744 \subsection{blktrace.h Definitions}
745 Files which include $<linux/blktrace.h>$ are supplied with the following
769 \subsection{blktrace.h Routines}
770 Files which include $<linux/blktrace.h>$ are supplied with the following