Re: [PATCH 1/1] network memory allocator.

Bill Fink
2006-08-16T02:52:48Z

On Tue, 15 Aug 2006, Evgeniy Polyakov wrote:

> On Tue, Aug 15, 2006 at 03:49:28PM +0200, Peter Zijlstra (a.p.zijlstra@chello.nl) wrote:
>
> > It could if you can provide adequate detection of memory pressure and
> > fallback to a degraded mode within the same allocator/stack and can
> > guarantee limited service to critical parts.
>
> It is not needed, since network allocations are separated from main
> system ones.
> I think I need to show an example here.
>
> Let's main system works only with TCP for simplicity.
> Let's maximum allowed memory is limited by 1mb (it is 768k on machine
> with 1gb of ram).

The maximum amount of memory available for TCP on a system with 1 GB
of memory is 768 MB (not 768 KB).

[bill@chance4 ~]$ cat /proc/meminfo
MemTotal: 1034924 kB
...

[bill@chance4 ~]$ cat /proc/sys/net/ipv4/tcp_mem
98304 131072 196608

Since tcp_mem is in pages (4K in this case), maximum TCP memory
is 196608*4K or 768 MB.

Or am I missing something obvious.

-Bill