Re: More than 1M open file descriptors

[Felipe Balbi]

On Wed, May 19, 2010 at 04:52:56PM +0200, ext John Masinter wrote:
> I'm a software engineer and work with a fortune-500 company. We have a
> line of linux-powered network security appliances and I am responsible
> for Linux / OS development.
> Our multi-core appliance handles a large number of low-bandwith tcp
> connections, and after years of performance streamlining, we have hit
> the kernel's million tcp connection limit.
> Is there a kernel hack to increase the file descriptor limit beyond 1M
> to that we may have more than 1M open tcp connections? If this is
> discussed elsewhere, please point me in the right direction. Many
> thanks to everyone that contributes to open source.

look into fs/file.c
increasing sysctl_nr_open like below should help:

diff --git a/fs/file.c b/fs/file.c
index 87e1290..23c83df 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -27,9 +27,9 @@ struct fdtable_defer {
 	struct fdtable *next;
 };
 
-int sysctl_nr_open __read_mostly = 1024*1024;
+int sysctl_nr_open __read_mostly = 4*1024*1024;
 int sysctl_nr_open_min = BITS_PER_LONG;
-int sysctl_nr_open_max = 1024 * 1024; /* raised later */
+int sysctl_nr_open_max = 4 * 1024 * 1024; /* raised later */
 
 /*
  * We use this list to defer free fdtables that have vmalloced

you can also do it via /proc AFAICT.

--
balbi

DefectiveByDesign.org
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