Re: What's taking so long??

[Gary Thomas <gary@mlbassoc.com>]

On 01/20/2011 09:04 AM, Koen Kooi wrote:
>
> Op 20 jan 2011, om 16:58 heeft Joshua Lock het volgende geschreven:
>
>> On Thu, 2011-01-20 at 08:11 -0700, Gary Thomas wrote:
>>> My target platform/distro uses IPK and I have a local kernel
>>> recipe which is based on the pre linux-yocto recipe that was
>>> used by Poky.  When I build&  package the kernel, I have
>>> terrible performance - this is new, it used to be just fine.
>>>
>>> Here's what I mean.  Building for my kernel and timing the
>>> various steps, e.g.
>>>    % time bitbake virtual/kernel -c compile
>>>
>>> My kernel:
>>>    compile            1m49s
>>>    deploy             0m16s
>>>    populate_sysroot   0m38s
>>>    package           23m20s
>>>
>>> Just to compare, using OTS Poky for BeagleBoard:
>>>    compile            5m07s
>>>    deploy             0m36s
>>>    populate_sysroot   0m29s
>>>    package            5m02s
>>>
>>> That's a five-fold difference in the time to build&  package
>>> the kernel.
>>
>> This is a significant performance impact. Thanks for taking the time to
>> do some profiling.
>>
>> I've filed a bug http://bugzilla.pokylinux.org/show_bug.cgi?id=666 and
>> we'll get someone looking into that as a matter of priority.
>>
>>>
>>> What am I doing [wrong?] that makes this so?
>>> Would it be better if I switched to RPM like the BB is using?
>>>
>>
>> It looks like the slow paths are in package format independent code, so
>> probably not.
>
>> From a chat I had with RP 2 weeks ago:
>
> Koen: there's still something slow in bitbake log output
> Koen: do_package takes eons (>  10mins) with almost zero IO and CPU
> Koen: ctrl-c'ing it shows it's in the installed-but-not-packaged output
> Richard Purdie: poky's bitbake or upstream?
> Koen: I only tried poky bitbake so far
> Koen: upstream is slow as well, but I don't recall being so slow
> Koen: we talked about it at ELC
> Richard Purdie: My memory isn't remembering that
> Richard Purdie: This is do_package for the kernel or something large?
> Koen: kernel
> Koen: but I think anything would trigger it
> Koen: it feels like bitbake is only doing N lines of output per second
> Koen: effectively throttling it
> Koen: and with you have a 4k lines out output....
> Richard Purdie: The message handling means thread context switching
> Richard Purdie: in runqueue.py there is a number 4096 and a 0 on the line below
> Richard Purdie: try changing the 0 for something like 100000
> Richard Purdie: You won't get nice console output but it might run faster
> Richard Purdie: Was poky running "faster" until recently?
> Koen: I think so
> Koen: I haven't measured it
>
> Does doing:
>
> Richard Purdie: in runqueue.py there is a number 4096 and a 0 on the line below
> Richard Purdie: try changing the 0 for something like 100000
>
> help?

No.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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