userland boot time

Koen Kooi k.kooi at
Tue Jan 22 13:40:06 CET 2008

Hash: SHA1

Richard Purdie schreef:
| On Tue, 2008-01-22 at 13:19 +1100, Carsten Haitzler wrote:
|> On Tue, 22 Jan 2008 00:26:39 +0000 Richard Purdie <rpurdie at>
|>> You also need to keep in mind the games the kernel plays on your behalf
|>> with dynamic libraries. Each app does not have its own copy of the
|>> library, these are loaded once and them mmaped read only into each
|>> process apart from the writable sections which are marked for copy on
|>> write.
|> oh - i know. almost every lib i know has a fair number of writable
sections -
|> also the mmap setup does take time as does the search for the lib
|> multiple dirs for the lib).
| If the build system is working properly, it should find it first time.
| If its not, the rpath magic is wrong.
|>> I know OM doesn't use it atm but a lot of the linking overhead can be
|>> reduced with prelink in two ways. Firstly by analysing the whole system,
|>> each library can be given a unique load address avoiding any need to
|>> relocate anything. Secondly, the prelinked tables can be checked for
|>> validity and used instead of the normal linking process.
|> yeah. this might help. with C though i have yet to find any real
|> difference. c++ though seems to have a massive gain.
| In a handheld arm C based system like Poky, I see a measurable
| difference in device boot time and application startup time....

x11-image shows similar improvements

| My experiences suggest otherwise. Poky has a prelink .bb recipe and I've
| just synced it into OE so it has the eabi fixes too if anyone wants to
| experiment.

I'll try that on my gta01.



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