[Yum-devel] yum on an olpc machine (slooooooooooow)

[Panu Matilainen]

On Sat, 16 Dec 2006, seth vidal wrote:
> On Sat, 2006-12-16 at 13:48 +0200, Panu Matilainen wrote:
>>> The reason I didn't go this route for  FC5 anaconda is that it's just
>>> the same problem as having hdlist, etc.  Multiple versions of the same
>>> metadata, the problem we were trying to avoid by moving to repodata.
>>> I'd strongly argue this is the wrong approach.
>>
>> +1
>>
>> I suggest looking closer at where the time is *really* spent. Remember the
>> libxml2 "slowness" which turned out to be something in the way things are
>> copied between C and python? Is it really the xml parsing where most of
>> the time is spent, or is it something else like sqlite interactions or...?
>> Parsing those xml files sure isn't cheap, but it's not *that* slow in
>> C/C++ - I'd look for other places first.
>>
>> Here's one easy target for optimization (the time difference is
>> consistent over successive runs):
>
> Here's the output of the same on the olpc box:
> multiple runs here so read through them all:
>
> -bash-3.1# time yum --disablerepo='*' --enablerepo='extras' list
> available >> /dev/null
             ^^^^^^^^^^^^

> looks like it is less important on the olpc machine. given the numbers.
> It shaves a little less than a second. Keep in mind in that run of 1m38s
> it is only parsing primary.xml.gz for extras.

That's because you're redirecting output of both to /dev/null. Time it 
without that redirection like it was in my examples.

 	- Panu -