This is correct significant figures/units based on the precision of our
measurements, but it does not reflect our actual certainty re the output
data, since in reality, confidence is diminished by temperature, device,
hardware revision, time of day/month/year, spurious activity, data
connectivity, app install list, inherent randomness of multiprogramming,
sensor activity, user interaction, /data caches, build-by-build
differences, charging state, data fragmentation, race-driven sleeps,
cosmic radiation, factory defects, local magnetic or gravitational field
differences, changes in device momentum, or other known and unknown
causes.
Bug: N/A
Test: run perfboot.py, and output has:
mean: 10801 ms
median: 10801 ms
standard deviation: 18 ms
Change-Id: I796396acc203b29e9a14e4d6dffa58db7b8cd9fb
device.shell() was changed to return a (stdout, stderr) tuple in
the following CL.
https://android-review.googlesource.com/170420
This CL fixes perfboot.py to work with the return value.
Change-Id: I85d72fc63c1f96257fb19c3051482991a7b4049d
The current behavior, which is to use tags[-1] for end_tag, is good
enough in most cases, but sometime it makes more sense to use a
different one as end_tag.
For example, when optimizing APK scanning code in package manager,
using 'boot_progress_pms_scan_end' as end_tag would give us quicker
benchmark iterations as well as more relevant numbers possibly with
a smaller standard deviation.
Change-Id: Ic6371c936b36d1d87e9742502fd8958682a3b7d5
This CL adds --apk-dir option, which specifies the directory
that contains APK files to be installed before measuring
boot time.
BUG: 22207911
Change-Id: Ifeacf34c779248686443a9ef02485272c140a456
'sf_stop_bootanim' is useful for tracking the time wasted by
showing the 'outro' part of the boot animation.
'wm_boot_animation_done' is also useful for tracking user
perceived boot time.
(cherry-pick of cbcf2778c3)
Bug: 22207911
Change-Id: I3549338a2161fa29675993c239f57809270797f8
perfboot.py repeats the record of each event log during Android
boot specified times. By default, interval between measurements
is adjusted in such a way that CPUs are cooled down sufficiently
to avoid boot time slowdown caused by CPU thermal throttling.
This script also works around the issue of dropbox slowing down
boot time on userdebug build (http://b/20890386) by limiting
the number of files to be created by dropbox.
The result is output in a tab-separated value format.
BUG: 22207911
Change-Id: I0ddbac5d1c941efda87bc6db6388d8194d4bb3dd
