As changing NR_OPEN from 1024*1024 to 16*1024*1024 was considered a litle
bit dangerous, just let it default to 1024*1024 but adds a new sysctl
to let sysadmins change this value.

Thank you

[PATCH] get rid of NR_OPEN and introduce a sysctl_nr_open

NR_OPEN (historically set to 1024*1024) actually forbids processes to open 
more than 1024*1024 handles.

Unfortunatly some production servers hit the not so 'ridiculously high value' 
of 1024*1024 file descriptors per process.

Changing NR_OPEN is not considered safe because of vmalloc space potential 
exhaust.

This patch introduces a new sysctl (/proc/sys/fs/nr_open) wich defaults to 
1024*1024, so that admins can decide to change this limit if their workload 
needs it.


Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

  Documentation/filesystems/proc.txt |    8 ++++++++
  Documentation/sysctl/fs.txt        |   10 ++++++++++
  fs/file.c                          |    8 +++++---
  include/linux/fs.h                 |    2 +-
  kernel/sys.c                       |    2 +-
  kernel/sysctl.c                    |    8 ++++++++
  6 files changed, 33 insertions(+), 5 deletions(-)