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Firefox OS/Performance/Boot Sequence Optimization: Difference between revisions
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Revision as of 13:59, 1 February 2015
, 1 February 2015Lakrits moved page FirefoxOS/Performance/Boot Sequence Optimization to Firefox OS/Performance/Boot Sequence Optimization: The official spelling of "Firefox OS" leaves a space between the two parts of the name. It's easier to find a page if the...
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m (Lakrits moved page FirefoxOS/Performance/Boot Sequence Optimization to Firefox OS/Performance/Boot Sequence Optimization: The official spelling of "Firefox OS" leaves a space between the two parts of the name. It's easier to find a page if the...) |
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==The Plan== | ==The Plan== | ||
[[FirefoxOS/Performance/Boot_Profiling]] | * [[FirefoxOS/Performance/Boot_Profiling|Boot Profiling]] | ||
* [[FirefoxOS/Performance/Boot_Timing_Automation|Boot Timing Automation]] | |||
==Bootchart== | ==Bootchart== | ||
| Line 88: | Line 89: | ||
A rough idea of what was seen, as well as empirical hypotheses: | A rough idea of what was seen, as well as empirical hypotheses: | ||
* B2G starts after roughly 8s of mysterious "stuff", impenetrable to bootchart | * B2G starts after roughly 8s of mysterious "stuff", impenetrable to bootchart | ||
* Based on kmsg, it | * Based on kmsg, it is likely that time between 5s and 8s is init script execution up until <code>|class_start main|</code> in the init.rc (which launches B2G service) | ||
* Vertical | * Vertical is shown as coming up around 16s, however it is actually just the preallocated process at this point, which later becomes vertical (around 22s-23s). | ||
* As well it seems we are only at the init entry point around 4 seconds in anyway (based on inserted kernel log output) | |||
* As well it seems | |||
* As such it is likely that | * As such it is likely that | ||
<code> | |||
** -3.5s = bootloader + Early kernel | ** -3.5s = bootloader + Early kernel | ||
** | ** 0s = kernel timing initialized | ||
** ~4.5s = init main | ** ~4.5s = init main | ||
** 7-8s = B2G | ** 7-8s = B2G | ||
** ~14s = (Nuwa) | ** ~14s = (Nuwa) | ||
** ~16s = | ** ~16s = Preallocated | ||
** ~25s = UI presented to user | ** ~22s = Homescreen app? | ||
** ~25s = UI presented to user | |||
</code> | |||
Of note is that there exists a pronounced black screen between the T2mobile and the "Mozilla Developer Network" logos, that was introduced at some point. Dave Huseby has noted in the past that such a noticeable black screen exists in other devices. This was less visible in past versions. | Of note is that there exists a pronounced black screen between the T2mobile and the "Mozilla Developer Network" logos, that was introduced at some point. Dave Huseby has noted in the past that such a noticeable black screen exists in other devices. This was less visible in past versions. | ||
Of course, there is more concrete data, but that is the general trend of things. | Of course, there is more concrete data, but that is the general trend of things. | ||
[http://people.mozilla.org/~jbailey/v121-2-premainb2g/ Experiment #1] | [http://people.mozilla.org/~jbailey/v121-2-premainb2g/ Experiment #1] | ||