Re: Is kernel 2.6.11 adjust tcp_max_syn_backlog incorrectly?

David S. Miller
2005-06-13T21:25:50Z

From: Andi Kleen <ak@muc.de>
Date: Sat, 11 Jun 2005 12:25:08 +0200

> Yes, there were some changes here when it was converted to a common
> function for all hash tables (alloc_large_system_hash - the function
> with the argument list from hell). Anyways, here's a quick fix.
>
> DaveM for your consideration.
>
> Adjust TCP mem order check to new alloc_large_system_hash
>
> Signed-off-by: Andi Kleen <ak@suse.de>

I just reread those NUMA changes, and they changed the heuristics
for sizing things at the same time as moving over to the
alloc_large_system_hash() change.

The change was to move from (21 - PAGE_SHIFT) and (23 - PAGE_SHIFT)
to (25 - PAGE_SHIFT) and (27 - PAGE_SHIFT) respectively.

This is the part of the NUMA TCP changes that made the sysctl setting
behavior differ.

Andi's patch is the least intrusive fix for 2.6.12, so I will
apply it. But longer term these heuristics need to be revisited
as a whole.