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

On Tue, May 06, 2014 at 01:17:58PM -0700, Eric Dumazet wrote:

On Tue, 2014-05-06 at 11:32 -0700, Andi Kleen wrote:

quoted

quoted

We simply can not compete with user space, as a programmer is free to
keep what he really wants/needs.

Not true.

You can shake the kernel as much as you want, you wont make :
- a TCP socket
- a dentry
- an inode
- a file structure
- eventpoll structures (assuming epoll use)
- 2 dst per flow.

In 1024 bytes of memory, and keep an efficient kernel to handle
arbitrary number of sockets using the venerable and slow BSD socket api.

I was objecting to the "crazy things like LWIP" comment from Josh, not
to your patches in general.

My primary statement was that it's crazy to use something like LWIP just
because you want a *tiny* system.  We could argue about using LWIP
because you want a massively scalable system, or one that more closely
couples userspace and the kernel, but that's not the current goal in any
case.  So let's drop that branch of the thread. :)

I actually took a look at them but stopped at patch 22

Adding ~1000 lines of code to save few KB was the point I gave up.

Please consider ignoring that one and reading the rest; we could always
handle the routing table issue separately.

- Josh Triplett