Commit | Line | Data |
---|---|---|
fbdf23ec | 1 | .TH BLKPARSE 1 "March 6, 2007" "blktrace git\-20070306202522" "" |
98eee4e4 JA |
2 | |
3 | ||
4 | .SH NAME | |
5 | blkparse \- produce formatted output of event streams of block devices | |
6 | ||
7 | ||
8 | .SH SYNOPSIS | |
9 | .B blkparse [ \fIoptions\fR ] | |
10 | .br | |
11 | ||
12 | ||
13 | .SH DESCRIPTION | |
14 | The \fIblkparse\fR utility will attempt to combine streams of events for | |
15 | various devices on various CPUs, and produce a formatted output of the event | |
16 | information. Specifically, it will take the (machine-readable) output of the | |
17 | \fIblktrace\fR utility and convert it to a nicely formatted and human-readable | |
18 | form. | |
19 | ||
20 | As with \fIblktrace\fR, some details concerning \fIblkparse\fR | |
21 | will help in understanding the command line options presented below. | |
22 | ||
23 | ||
24 | .TP 2 | |
25 | \- | |
26 | By default, \fIblkparse\fR expects to run in a post-processing mode; one where | |
27 | the trace events have been saved by a previous run of blktrace, and blkparse | |
28 | is combining event streams and dumping formatted data. | |
29 | ||
30 | blkparse may be run in a live manner concurrently with blktrace by specifying | |
31 | \fB\-i \-\fR to blkparse, and combining it with the live option for blktrace. | |
32 | An example would be: | |
33 | ||
34 | % blktrace \-d /dev/sda \-o \- | blkparse \-i \- | |
35 | ||
36 | .TP 2 | |
37 | \- | |
38 | You can set how many blkparse batches event reads via the \fB\-b\fR option, the | |
39 | default is to handle events in batches of 512. | |
40 | ||
41 | .TP 2 | |
42 | \- | |
43 | If you have saved event traces in blktrace with different output names (via | |
44 | the \fB\-o\fR option to blktrace), you must specify the same input name via the | |
45 | \fB\-i\fR option. | |
46 | ||
47 | .TP 2 | |
48 | \- | |
49 | The format of the output data can be controlled via the \fB\-f\fR or \fB\-F\fR | |
50 | options \-\- see OUTPUT DESCRIPTION AND FORMATTING for details. | |
51 | ||
52 | .PP | |
53 | By default, blkparse sends formatted data to standard output. This may | |
54 | be changed via the \fB\-o\fR option, or text output can be disabled via the | |
55 | \fB\-O\fR option. A merged binary stream can be produced using the \fB\-d\fR | |
56 | option. | |
57 | ||
58 | ||
59 | ||
60 | .SH OPTIONS | |
61 | ||
62 | \-b \fIbatch\fR | |
63 | .br | |
64 | \-\-batch={batch} | |
65 | .RS | |
66 | Standard input read batching | |
67 | .RE | |
68 | ||
69 | \-i \fIfile\fR | |
70 | .br | |
71 | \-\-input=\fIfile\fR | |
72 | .RS | |
73 | Specifies base name for input files \-\- default is \fIdevice\fR.blktrace.\fIcpu\fR. | |
74 | ||
75 | As noted above, specifying \fB\-i \-\fR runs in live mode with blktrace | |
76 | (reading data from standard in). | |
77 | .RE | |
78 | ||
79 | \-F \fItyp,fmt\fR | |
80 | .br | |
81 | \-\-format=\fItyp,fmt\fR | |
82 | .br | |
83 | \-f \fIfmt\fR | |
84 | .br | |
85 | \-\-format\-spec=\fIfmt\fR | |
86 | .RS | |
87 | Sets output format | |
88 | (See OUTPUT DESCRIPTION AND FORMATTING for details.) | |
89 | ||
90 | The \-f form specifies a format for all events | |
91 | ||
92 | The \-F form allows one to specify a format for a specific | |
93 | event type. The single\-character \fItyp\fR field is one of the | |
94 | action specifiers described in ACTION IDENTIFIERS. | |
95 | .RE | |
96 | ||
19cfaf3f AB |
97 | \-M |
98 | .br | |
99 | \-\-no-msgs | |
100 | .RS | |
101 | When \-d is specified, this will stop messages from being output to the | |
102 | file. (Can seriously reduce the size of the resultant file when using | |
103 | the CFQ I/O scheduler.) | |
104 | .RE | |
105 | ||
98eee4e4 JA |
106 | \-h |
107 | .br | |
108 | \-\-hash\-by\-name | |
109 | .RS | |
110 | Hash processes by name, not by PID | |
111 | .RE | |
112 | ||
113 | \-o \fIfile\fR | |
114 | .br | |
115 | \-\-output=\fIfile\fR | |
116 | .RS | |
117 | Output file | |
118 | .RE | |
119 | ||
120 | \-O | |
121 | .br | |
122 | \-\-no\-text\-output | |
123 | .RS | |
124 | Do \fInot\fR produce text output, used for binary (\fB\-d\fR) only | |
125 | .RE | |
126 | ||
127 | \-d \fIfile\fR | |
128 | .br | |
129 | \-\-dump\-binary=\fIfile\fR | |
130 | .RS | |
131 | Binary output file | |
132 | .RE | |
133 | ||
134 | \-q | |
135 | .br | |
136 | \-\-quiet | |
137 | .RS | |
138 | Quiet mode | |
139 | .RE | |
140 | ||
141 | \-s | |
142 | .br | |
143 | \-\-per\-program\-stats | |
144 | .RS | |
145 | Displays data sorted by program | |
146 | .RE | |
147 | ||
148 | \-t | |
149 | .br | |
150 | \-\-track\-ios | |
151 | .RS | |
152 | Display time deltas per IO | |
153 | .RE | |
154 | ||
155 | \-w \fIspan\fR | |
156 | .br | |
157 | \-\-stopwatch=\fIspan\fR | |
158 | .RS | |
159 | Display traces for the \fIspan\fR specified \-\- where span can be: | |
160 | .br | |
161 | \fIend\-time\fR \-\- Display traces from time 0 through \fIend\-time\fR (in ns) | |
162 | .br | |
163 | or | |
164 | .br | |
165 | \fIstart:end\-time\fR \-\- Display traces from time \fIstart\fR | |
166 | through end\-time (in ns). | |
167 | .RE | |
168 | ||
169 | \-v | |
170 | .br | |
171 | \-\-verbose | |
172 | .RS | |
173 | More verbose marginal on marginal errors | |
174 | .RE | |
175 | ||
176 | \-V | |
177 | .br | |
178 | \-\-version | |
179 | .RS | |
180 | Display version | |
181 | .RE | |
182 | ||
183 | ||
184 | .SH "TRACE ACTIONS" | |
185 | The following trace actions are recognised: | |
186 | ||
187 | .HP 4 | |
188 | \fBC -- complete\fR | |
189 | A previously issued request has been completed. The output will detail the | |
190 | sector and size of that request, as well as the success or failure of it. | |
191 | ||
192 | .HP 4 | |
193 | \fBD -- issued\fR | |
194 | A request that previously resided on the block layer queue or in the i/o | |
195 | scheduler has been sent to the driver. | |
196 | ||
197 | .HP 4 | |
198 | \fBI -- inserted\fR | |
199 | A request is being sent to the i/o scheduler for addition to the internal queue | |
200 | and later service by the driver. The request is fully formed at this time. | |
201 | ||
202 | .HP 4 | |
203 | \fBQ -- queued\fR | |
204 | This notes intent to queue i/o at the given location. No real requests exists | |
205 | yet. | |
206 | ||
207 | .HP 4 | |
208 | \fBB -- bounced\fR | |
209 | The data pages attached to this \fIbio\fR are not reachable by the hardware | |
210 | and must be bounced to a lower memory location. This causes a big slowdown in | |
211 | i/o performance, since the data must be copied to/from kernel buffers. Usually | |
212 | this can be fixed with using better hardware -- either a better i/o controller, | |
213 | or a platform with an IOMMU. | |
214 | ||
215 | .HP 4 | |
216 | \fBM -- back merge\fR | |
217 | A previously inserted request exists that ends on the boundary of where this i/o | |
218 | begins, so the i/o scheduler can merge them together. | |
219 | ||
220 | .HP 4 | |
221 | \fBF -- front merge\fR | |
222 | Same as the back merge, except this i/o ends where a previously inserted | |
223 | requests starts. | |
224 | ||
225 | .HP 4 | |
226 | \fBM --front or back merge\fR | |
227 | One of the above | |
228 | ||
229 | .HP 4 | |
230 | \fBM -- front or back merge\fR | |
231 | One of the above. | |
232 | ||
233 | .HP 4 | |
234 | \fBG -- get request\fR | |
235 | To send any type of request to a block device, a \fIstruct request\fR | |
236 | container must be allocated first. | |
237 | ||
238 | .HP 4 | |
239 | \fBS -- sleep\fR | |
240 | No available request structures were available, so the issuer has to wait for | |
241 | one to be freed. | |
242 | ||
243 | .HP 4 | |
244 | \fBP -- plug\fR | |
245 | When i/o is queued to a previously empty block device queue, Linux will plug the | |
246 | queue in anticipation of future ios being added before this data is needed. | |
247 | ||
248 | .HP 4 | |
249 | \fBU -- unplug\fR | |
250 | Some request data already queued in the device, start sending requests to the | |
251 | driver. This may happen automatically if a timeout period has passed (see next | |
252 | entry) or if a number of requests have been added to the queue. | |
253 | ||
254 | .HP 4 | |
255 | \fBT -- unplug due to timer\fR | |
256 | If nobody requests the i/o that was queued after plugging the queue, Linux will | |
257 | automatically unplug it after a defined period has passed. | |
258 | ||
259 | .HP 4 | |
260 | \fBX -- split\fR | |
261 | On raid or device mapper setups, an incoming i/o may straddle a device or | |
262 | internal zone and needs to be chopped up into smaller pieces for service. This | |
263 | may indicate a performance problem due to a bad setup of that raid/dm device, | |
264 | but may also just be part of normal boundary conditions. dm is notably bad at | |
265 | this and will clone lots of i/o. | |
266 | ||
267 | .HP 4 | |
268 | \fBA -- remap\fR | |
269 | For stacked devices, incoming i/o is remapped to device below it in the i/o | |
270 | stack. The remap action details what exactly is being remapped to what. | |
271 | ||
272 | ||
273 | ||
274 | ||
275 | .SH "OUTPUT DESCRIPTION AND FORMATTING" | |
276 | ||
277 | The output from blkparse can be tailored for specific use -- in particular, to ease | |
278 | parsing of output, and/or limit output fields to those the user wants to see. The | |
279 | data for fields which can be output include: | |
280 | ||
281 | .IP \fBa\fR 4 | |
282 | Action, a (small) string (1 or 2 characters) -- see table below for more details | |
283 | ||
284 | .IP \fBc\fR 4 | |
285 | CPU id | |
286 | ||
287 | .IP \fBC\fR 4 | |
288 | Command | |
289 | ||
290 | .IP \fBd\fR 4 | |
291 | RWBS field, a (small) string (1-3 characters) -- see section below for more details | |
292 | ||
293 | .IP \fBD\fR 4 | |
294 | 7-character string containing the major and minor numbers of | |
295 | the event's device (separated by a comma). | |
296 | ||
297 | .IP \fBe\fR 4 | |
298 | Error value | |
299 | ||
300 | .IP \fBm\fR 4 | |
301 | Minor number of event's device. | |
302 | ||
303 | .IP \fBM\fR 4 | |
304 | Major number of event's device. | |
305 | ||
306 | .IP \fBn\fR 4 | |
307 | Number of blocks | |
308 | ||
309 | .IP \fBN\fR 4 | |
310 | Number of bytes | |
311 | ||
312 | .IP \fBp\fR 4 | |
313 | Process ID | |
314 | ||
315 | .IP \fBP\fR 4 | |
316 | Display packet data \-\- series of hexadecimal values | |
317 | ||
318 | .IP \fBs\fR 4 | |
319 | Sequence numbers | |
320 | ||
321 | .IP \fBS\fR 4 | |
322 | Sector number | |
323 | ||
324 | .IP \fBt\fR 4 | |
325 | Time stamp (nanoseconds) | |
326 | ||
327 | .IP \fBT\fR 4 | |
328 | Time stamp (seconds) | |
329 | ||
330 | .IP \fBu\fR 4 | |
331 | Elapsed value in microseconds (\fI\-t\fR command line option) | |
332 | ||
333 | .IP \fBU\fR 4 | |
334 | Payload unsigned integer | |
335 | ||
336 | .PP | |
337 | Note that the user can optionally specify field display width, and optionally a | |
338 | left-aligned specifier. These precede field specifiers, with a '%' character, | |
339 | followed by the optional left-alignment specifier (\-) followed by the width (a | |
340 | decimal number) and then the field. | |
341 | ||
342 | Thus, to specify the command in a 12-character field that is left aligned: | |
343 | ||
344 | \-f "%\-12C" | |
345 | ||
346 | ||
347 | .SH "ACTION IDENTIFIERS" | |
348 | ||
349 | The following table shows the various actions which may be output: | |
350 | ||
351 | .IP A | |
352 | IO was remapped to a different device | |
353 | ||
354 | .IP B | |
355 | IO bounced | |
356 | ||
357 | .IP C | |
358 | IO completion | |
359 | ||
360 | .IP D | |
361 | IO issued to driver | |
362 | ||
363 | .IP F | |
364 | IO front merged with request on queue | |
365 | ||
366 | .IP G | |
367 | Get request | |
368 | ||
369 | .IP I | |
370 | IO inserted onto request queue | |
371 | ||
372 | .IP M | |
373 | IO back merged with request on queue | |
374 | ||
375 | .IP P | |
376 | Plug request | |
377 | ||
378 | .IP Q | |
379 | IO handled by request queue code | |
380 | ||
381 | .IP S | |
382 | Sleep request | |
383 | ||
384 | .IP T | |
385 | Unplug due to timeout | |
386 | ||
387 | .IP U | |
388 | Unplug request | |
389 | ||
390 | .IP X | |
391 | Split | |
392 | ||
393 | ||
394 | .SH "RWBS DESCRIPTION" | |
395 | ||
64c03161 DW |
396 | This is a small string containing at least one character ('R' for read, 'W' |
397 | for write, or 'D' for block discard operation), and optionally either | |
398 | a 'B' (for barrier operations) or 'S' (for synchronous operations). | |
98eee4e4 JA |
399 | |
400 | ||
401 | .SH "DEFAULT OUTPUT" | |
402 | ||
403 | The standard header (or initial fields displayed) include: | |
404 | ||
405 | "%D %2c %8s %5T.%9t %5p %2a %3d" | |
406 | ||
407 | Breaking this down: | |
408 | ||
409 | .IP \fB%D\fR | |
410 | Displays the event's device major/minor as: %3d,%\-3d. | |
411 | ||
412 | .IP \fB%2c\fR | |
413 | CPU ID (2-character field). | |
414 | ||
415 | .IP \fB%8s\fR | |
416 | Sequence number | |
417 | ||
418 | .IP \fB%5T.%9t\fR | |
419 | 5-character field for the seconds portion of the time stamp and a 9-character field for the nanoseconds in the time stamp. | |
420 | ||
421 | .IP \fB%5p\fR | |
422 | 5-character field for the process ID. | |
423 | ||
424 | .IP \fB%2a\fR | |
425 | 2-character field for one of the actions. | |
426 | ||
427 | .IP \fB%3d\fR | |
428 | 3-character field for the RWBS data. | |
429 | ||
430 | Seeing this in action: | |
431 | ||
432 | 8,0 3 1 0.000000000 697 G W 223490 + 8 [kjournald] | |
433 | ||
434 | The header is the data in this line up to the 223490 (starting block). | |
435 | The default output for all event types includes this header. | |
436 | ||
437 | ||
438 | ||
439 | .SH "DEFAULT OUTPUT PER ACTION" | |
440 | ||
441 | \fBC \-\- complete\fR | |
442 | .RS 4 | |
443 | If a payload is present, this is presented between | |
444 | parenthesis following the header, followed by the error value. | |
445 | ||
446 | If no payload is present, the sector and number of blocks are presented | |
447 | (with an intervening plus (+) character). If the \fB\-t\fR option | |
448 | was specified, then the elapsed time is presented. In either case, | |
449 | it is followed by the error value for the completion. | |
450 | .RE | |
451 | ||
452 | \fBB \-\- bounced\fR | |
453 | .br | |
454 | \fBD \-\- issued\fR | |
455 | .br | |
456 | \fBI \-\- inserted\fR | |
457 | .br | |
458 | \fBQ \-\- queued\fR | |
459 | .RS 4 | |
460 | If a payload is present, the number of payload bytes | |
461 | is output, followed by the payload in hexadecimal between parenthesis. | |
462 | ||
463 | If no payload is present, the sector and number of blocks are presented | |
464 | (with an intervening plus (+) character). If the \fB\-t\fR option was | |
465 | specified, then the elapsed time is presented (in parenthesis). In | |
466 | either case, it is followed by the command associated with the event | |
467 | (surrounded by square brackets). | |
468 | .RE | |
469 | ||
470 | \fBF \-\- front merge\fR | |
471 | .br | |
472 | \fBG \-\- get request\fR | |
473 | .br | |
474 | \fBM \-\- back merge\fR | |
475 | .br | |
476 | \fBS \-\- sleep\fR | |
477 | .RS 4 | |
478 | The starting sector and number of blocks is output | |
479 | (with an intervening plus (+) character), followed by the command | |
480 | associated with the event (surrounded by square brackets). | |
481 | .RE | |
482 | ||
483 | \fBP \-\- plug\fR | |
484 | .RS 4 | |
485 | The command associated with the event (surrounded by | |
486 | square brackets) is output. | |
487 | .RE | |
488 | ||
489 | \fBU \-\- unplug\fR | |
490 | .br | |
491 | \fBT \-\- unplug due to timer\fR | |
492 | .RS 4 | |
493 | The command associated with the event | |
494 | (surrounded by square brackets) is output, followed by the number of | |
495 | requests outstanding. | |
496 | .RE | |
497 | ||
498 | \fBX \-\- split\fR | |
499 | .RS 4 | |
500 | The original starting sector followed by the new | |
501 | sector (separated by a slash (/) is output, followed by the command | |
502 | associated with the event (surrounded by square brackets). | |
503 | .RE | |
504 | ||
505 | \fBA \-\- remap\fR | |
506 | .RS 4 | |
507 | Sector and length is output, along with the original | |
508 | device and sector offset. | |
509 | .RE | |
510 | ||
511 | ||
512 | .SH EXAMPLES | |
513 | To trace the i/o on the device \fI/dev/hda\fB and parse the output to human | |
514 | readable form, use the following command: | |
515 | ||
516 | % blktrace \-d /dev/sda \-o \- | blkparse \-i \- | |
517 | ||
518 | (see \fIblktrace\fR (8) for more information). | |
519 | This same behaviour can be achieve with the convenience script \fIbtrace\fR. | |
520 | The command | |
521 | ||
522 | % btrace /dev/sda | |
523 | ||
524 | has exactly the same effect as the previous command. See \fIbtrace\fR (8) for | |
525 | more information. | |
526 | ||
527 | To trace the i/o on a device and save the output for later processing with | |
528 | \fIblkparse\fR, use \fIblktrace\fR like this: | |
529 | ||
530 | % blktrace /dev/sda /dev/sdb | |
531 | ||
532 | This will trace i/o on the devices \fI/dev/sda\fR and \fI/dev/sdb\fR and save | |
533 | the recorded information in the files \fIsda\fR and \fIsdb\fR in the current | |
534 | directory, for the two different devices, respectively. This trace | |
535 | information can later be parsed by the \fIblkparse\fR utility: | |
536 | ||
537 | % blkparse sda sdb | |
538 | ||
539 | which will output the previously recorded tracing information in human | |
540 | readable form to stdout. | |
541 | ||
542 | ||
543 | .SH AUTHORS | |
544 | \fIblkparse\fR was written by Jens Axboe, Alan D. Brunelle and Nathan Scott. This | |
545 | man page was created from the \fIblktrace\fR documentation by Bas Zoetekouw. | |
546 | ||
547 | ||
548 | .SH "REPORTING BUGS" | |
549 | Report bugs to <linux\-btrace@vger.kernel.org> | |
550 | ||
551 | .SH COPYRIGHT | |
552 | Copyright \(co 2006 Jens Axboe, Alan D. Brunelle and Nathan Scott. | |
553 | .br | |
554 | This is free software. You may redistribute copies of it under the terms of | |
555 | the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. | |
556 | There is NO WARRANTY, to the extent permitted by law. | |
557 | .br | |
558 | This manual page was created for Debian by Bas Zoetekouw. It was derived from | |
559 | the documentation provided by the authors and it may be used, distributed and | |
560 | modified under the terms of the GNU General Public License, version 2. | |
561 | .br | |
562 | On Debian systems, the text of the GNU General Public License can be found in | |
563 | /usr/share/common\-licenses/GPL\-2. | |
564 | ||
565 | .SH "SEE ALSO" | |
566 | btrace (8), blktrace (8), verify_blkparse (1), blkrawverify (1), btt (1) | |
567 |