[PATCH 2.6] Number of proc entries based on NR_CPUS ?

[PATCH 2.6] Number of proc entries based on NR_CPUS ?

[Martin Hicks]

Here is a patch that makes the number of /proc entries be based on
NR_CPUS instead of just having a fixed number.  I think it is a good
idea now that big Linux machines are starting to appear.

The proper constant and slope of increase are up for argument too.

Patch is against the latest linux-2.5 bk tree.

Opinions?
mh

-- 
Martin Hicks                Wild Open Source Inc.
mort@wildopensource.com     613-266-2296


# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.1359  -> 1.1360 
#	include/linux/proc_fs.h	1.27    -> 1.28   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/11/08	mort@green.i.bork.org	1.1360
# Make PROC_NDYNAMIC based on NR_CPUS.
# --------------------------------------------
#
diff -Nru a/include/linux/proc_fs.h b/include/linux/proc_fs.h
--- a/include/linux/proc_fs.h	Sat Nov  8 12:38:34 2003
+++ b/include/linux/proc_fs.h	Sat Nov  8 12:38:34 2003
@@ -27,7 +27,7 @@
 /* Finally, the dynamically allocatable proc entries are reserved: */
 
 #define PROC_DYNAMIC_FIRST 4096
-#define PROC_NDYNAMIC      16384
+#define PROC_NDYNAMIC      (4096+32*NR_CPUS)
 
 #define PROC_SUPER_MAGIC 0x9fa0
 

Re: [PATCH 2.6] Number of proc entries based on NR_CPUS ?

[Anton Blanchard]

Hi Martin,

> Here is a patch that makes the number of /proc entries be based on
> NR_CPUS instead of just having a fixed number.  I think it is a good
> idea now that big Linux machines are starting to appear.
> 
> The proper constant and slope of increase are up for argument too.
> 
> Patch is against the latest linux-2.5 bk tree.

I think I first bumped that to 16k, that was needed on a 32way box.
At 128way my gut feeling is its 32k.

Linking the number of proc entries to the number of cpus is a bit crude
but its better than having it fixed.

FYI I think some networking people were complaining about this limit
when they create gobs of network interfaces (dummy devices?  ipsec?).
Each interface creates a bunch of /proc/sys/net entries...

Anton

Re: [PATCH 2.6] Number of proc entries based on NR_CPUS ?

[Martin Hicks]

On Sat, 2003-11-08 at 14:03, Anton Blanchard wrote:
> Hi Martin,
> 
> > Here is a patch that makes the number of /proc entries be based on
> > NR_CPUS instead of just having a fixed number.  I think it is a good
> > idea now that big Linux machines are starting to appear.
> > 
> > The proper constant and slope of increase are up for argument too.
> > 
> > Patch is against the latest linux-2.5 bk tree.
> 
> I think I first bumped that to 16k, that was needed on a 32way box.
> At 128way my gut feeling is its 32k.
> 

Okay, those are useful numbers to have.  This seems to be higher than
what is required by SGI's sn2.

> Linking the number of proc entries to the number of cpus is a bit crude
> but its better than having it fixed.

Yeah, I'm not sure what a really good solution is.  I really don't have
an urge to tear apart the proc code to make it more dynamic than this
compile time option.

> 
> FYI I think some networking people were complaining about this limit
> when they create gobs of network interfaces (dummy devices?  ipsec?).
> Each interface creates a bunch of /proc/sys/net entries...

Based on your guidlines above, we need a number of proc entries more
like:

8192 + 256*NR_CPUS

mh

-- 
Martin Hicks                Wild Open Source Inc.
mort@wildopensource.com     613-266-2296