Re: [PATCH] Shrinks sizeof(files_struct) and better layout

[Eric Dumazet <dada1@cosmosbay.com>]

David Lang a écrit :
> Ok, so if you have large numbers of CPU's and large page sizes it's not 
> useful. however, what about a 2-4 cpu machine with 4k page sizes, 8-32G 
> of ram (a not unreasonable Opteron system config) that will be running 
> 5,000-20,000 processes/threads?

Dont forget 'struct files_struct' are shared between threads of one process.

So may benefit from this 'special cache' only if you plan to run 20.000 processes.

> 
> I know people argue that programs that do such things are bad (and I 
> definantly agree that they aren't optimized), but the reality is that 
> some workloads are like that. if a machine is being built for such uses 
> configuring the kernel to better tolorate such use may be useful

If 20.000 process runs on a machine, I doubt the main problem of sysadmin is 
about the 'struct files_struct' placement in memory :)

Eric