There is no trivial way to reduce either of those. The zygote class
preloading is essential for good performance of the system after boot. The
package scan can in theory do some caching of its results after first boot,
but this is a lot of work and has the potential to introduce serious bugs if
the state gets out of sync (we've seen devices ship in the field with subtle
bugs in this area probably because they were trying to do such
optimizations).
Also the numbers you quote are pretty large. For example, a myTouch booting
Android takes about 11 seconds in zygote preloading and 7.5 seconds to scan
packages. If your hardware is that significantly slower than a myTouch, you
may be trimming functionality out of the platform and perhaps you can reduce
the class preload set (although you need to be extremely careful when doing
so to not break the performance of the system) or remove unneeded .apks.
Fwiw, on Nexus One class hardware class preloading takes 2.5 seconds and
package scanning 2 seconds. :}
On Mon, May 10, 2010 at 12:02 PM, Ashu <ashutosh.deshmukh2...@gmail.com>wrote:
> Hi, We are working on Android boot time reduction.
> We use OMAP3430 Board as our Hardware. Android version is 1.6 Donut.
>
> We used bootchart to visualize boot pattern. From it, we found that
> following things take bulk of time.
>
> 1.Zygote process. It actually do the proloading of java classes that
> takes @23 secs for its completion.
>
> 2. Package manager service.
> In logcat output, we can see that Package manager scans 4 dirs,
> /system/app,
> /system/framework,
> /data/app,
> /data/app-private.
>
> And it takes nearly 11-12 sec to scan packages as shown below from
> logcat output.
>
>
>
>
>
> I/PackageManager( 827): Got library android.test.runner in /system/
> framework/android.test.runner.jar
> I/PackageManager( 827): Got library com.android.im.plugin in /system/
> framework/com.android.im.plugin.jar
> W/PackageManager( 827): Running ENG build: no pre-dexopt!
> D/dalvikvm( 827): GC freed 6111 objects / 272568 bytes in 72ms
> D/PackageManager( 827): Scanning app dir /system/framework
> V/PackageParser( 827): android:backupAgent =
> com.android.internal.backup.SystemBackupAgent from android
> +com.android.internal.backup.SystemBackupAgent
> D/PackageManager( 827): Scanning app dir /system/app
> V/PackageParser( 827): android:backupAgent =
> com.android.providers.settings.SettingsBackupAgent from
> com.android.providers.settings+SettingsBackupAgent
> D/dalvikvm( 827): GC freed 3717 objects / 212000 bytes in 67ms
> V/PackageParser( 827): android:backupAgent =
> com.android.inputmethod.latin.LatinIMEBackupAgent from
> com.android.inputmethod.latin+LatinIMEBackupAgent
> E/PackageManager( 827): Package com.svox.pico has mismatched uid:
> 10014 on disk, 10015 in settings; read messages:
> E/PackageManager( 827): Read completed successfully: 35 packages, 5
> shared uids
> E/PackageManager( 827): Package android.tts has mismatched uid: 10015
> on disk, 10016 in settings
> I/PackageManager( 827): /system/app/SubscribedFeedsProvider.apk
> changed; collecting certs
> E/PackageManager( 827): Package com.android.providers.subscribedfeeds
> requires unavailable shared library com.google.android.gtalkservice;
> ignoring!
> W/PackageParser( 827): Intent filter for activity
> ActivityIntentInfo{439d7c88 com.android.camera.ReviewImage} defines no
> actions
> D/PackageManager( 827): Scanning app dir /data/app
> D/dalvikvm( 827): GC freed 5647 objects / 350752 bytes in 73ms
> I/PackageParser( 827): Impliciting adding
> android.permission.WRITE_EXTERNAL_STORAGE to old pkg
> com.avaw.luklukpro
> I/PackageParser( 827): Impliciting adding
> android.permission.WRITE_EXTERNAL_STORAGE to old pkg org.iii.ro.iiivpa
> I/PackageParser( 827): Impliciting adding
> android.permission.READ_PHONE_STATE to old pkg org.iii.ro.iiivpa
> E/PackageManager( 827): Package org.iii.ro.iiivpa has mismatched uid:
> 10016 on disk, 10014 in settings
> D/PackageManager( 827): Scanning app dir /data/app-private
> I/PackageManager( 827): Time to scan packages: 11.632 seconds
>
>
> My question is
> 1. How can we reduce this scan time?
> 2. Is there any other way/approach to reduce android boot time? I
> don't want to reduce android kernel boot time, it is short anyway.
>
>
>
> If this is not the right forum to ask this , please redirect me to
> correct place.
>
> Thanks in Advance.
>
>
>
>
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>
--
Dianne Hackborn
Android framework engineer
hack...@android.com
Note: please don't send private questions to me, as I don't have time to
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