| Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 1 | <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
| 2 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" |
| 3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > |
| Andrew Geissler | d25ed32 | 2020-06-27 00:28:28 -0500 | [diff] [blame] | 4 | <!--SPDX-License-Identifier: CC-BY-2.0-UK--> |
| Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 5 | |
| 6 | <chapter id='profile-manual-examples'> |
| 7 | |
| 8 | <title>Real-World Examples</title> |
| 9 | |
| 10 | <para> |
| 11 | This chapter contains real-world examples. |
| 12 | </para> |
| 13 | |
| 14 | <section id='slow-write-speed-on-live-images'> |
| 15 | <title>Slow Write Speed on Live Images</title> |
| 16 | |
| 17 | <para> |
| 18 | In one of our previous releases (denzil), users noticed that booting |
| 19 | off of a live image and writing to disk was noticeably slower. |
| 20 | This included the boot itself, especially the first one, since first |
| 21 | boots tend to do a significant amount of writing due to certain |
| 22 | post-install scripts. |
| 23 | </para> |
| 24 | |
| 25 | <para> |
| 26 | The problem (and solution) was discovered by using the Yocto tracing |
| 27 | tools, in this case 'perf stat', 'perf script', 'perf record' |
| 28 | and 'perf report'. |
| 29 | </para> |
| 30 | |
| 31 | <para> |
| 32 | See all the unvarnished details of how this bug was diagnosed and |
| 33 | solved here: Yocto Bug #3049 |
| 34 | </para> |
| 35 | </section> |
| 36 | |
| 37 | </chapter> |
| 38 | <!-- |
| 39 | vim: expandtab tw=80 ts=4 |
| 40 | --> |