memory footprint

[Igor Sysoev]

On Fri, Nov 09, 2007 at 01:25:04PM +0100, Jure Pe??ar wrote:

> On Fri, 9 Nov 2007 11:52:17 +0300
> Igor Sysoev <is at rambler-co.ru> wrote:
> 
> > What size of
> > 
> > fastcgi_buffer_size
> > fastcgi_buffers
> 
> Defaults (none of these are set in config).
> 
> Right now I see that nginx process that got me worried shrunk to 70MB. So the size definitely has to do something with buffers and number of connections. Is this relationship documented somewhere?

Now nginx preallocated some memory for each conneciton in worker_connections,
however, I'm going to change it. Other memory is allocated only on request
depening on

client_header_buffer_size
large_client_header_buffers
client_body_buffer_size
fastcgi_buffer_size
fastcgi_buffers
gzip_buffers
zlib memory: 200-400K

Have you use SSL ?


As to sparse memory allocation this case is possible:

     allocated          unmapped
!!!!!!!!!!!!!!!!!!!!!-------------

Then when some pages will be free(.), number of allocated pages is the same:

     allocated          unmapped
!!.....!........!...!-------------

because in general libc can not return these pages to kernel if last page
is still used. However, there are tricks such as FreeBSD malloc_options="H"
that allows to return this memory to kernel or so.


-- 
Igor Sysoev
http://sysoev.ru/en/