Re: [PATCH 08/24] net, diet: Make TCP metrics optional

Cong Wang
2014-05-06T18:33:13Z

On Tue, May 6, 2014 at 10:55 AM, <josh@joshtriplett.org> wrote:
> On Tue, May 06, 2014 at 01:16:43PM -0400, David Miller wrote:
>> From: josh@joshtriplett.org
>> Date: Tue, 6 May 2014 09:41:08 -0700
>>
>> > Every KB of RAM costs real money and SoC die area (for eDRAM/eSRAM).
>>
>> Another poster commented that 16MB of DRAM would be cheaper than
>> the 2MB of ram you have on these boards, probably one that fits
>> your size profile is available as well.
>>
>> 2MB is just a rediculous restriction.
>
> Embedded systems experts disagree with you there; there *are* systems
> where the most cost-efficient approach is a few MB (or a few hundred KB)
> of non-discrete memory. We're not talking about socketed memory or even
> soldered-down memory; we're talking about entire systems that fit on a
> small SoC die. The space not used by that extra RAM may well be better
> spent on CPU optimizations, or some other integrated component.
>
> Such boards will be built, and many of them will run Linux, despite your
> incredulity. When you're building millions of a board, it's well worth
> optimizing software to eliminate components from the bill of materials.

So why bothers 3.15+ Linux kernel? Why not use an old kernel e.g. 2.4.x?
2.4.x kernel doesn't have so many new features you want to get rid of here.