Re: Patch to reorder functions in the vmlinux to a defined order

[Arjan van de Ven <arjan@linux.intel.com>]

Tony Luck wrote:
> On 2/23/06, Arjan van de Ven <arjan@linux.intel.com> wrote:
>> As per previous discussions, Linus said he wanted a "static" list for this,
>> eg a list provided by the kernel tarbal, so that most people have the same
>> ordering at least. A script is provided to create this list based on
>> readprofile(1) output. The included list is provisional, and entirely biased
>> on my own testbox and me running a few kernel compiles and some other
>> things.
>>
>> I think that to get to a better list we need to invite people to submit
>> their own profiles, and somehow add those all up and base the final list on
>> that.
> 
> 1) How will this work in the face of CONFIG options that change the
> list of symbols present in your kernel?  E.g. my hot oprofile list
> might well contain a bunch of symbols from my NIC driver and whatever
> filesystem I'm pounding on.

that is fine; symbols that aren't actually present just are ignored by 
the linker in this case

>
> 2) If you add enough lists from enough people, perhaps you'll get enough
> coverage of the kernel with all their different workloads, that you'll have
> too much to fit into the 2M page.

I am more optimistic; the total kernel size in "distro" configuration is 
about 3.5Mb. I would find it hard to believe that more than half of that 
is "hot" code even in a "many people send their profiles" setup.