[PATCH] NR_OPEN should be raised a litle bit

[Eric Dumazet]

Time has come to change NR_OPEN value, some production servers hit the
not so 'ridiculously high value' of 1024*1024 file descriptors per process.

This is safe to raise this value, because alloc_fd_array() uses
vmalloc() for large arrays and vmalloc() returns NULL if a too large
allocation is attempted (or in case of memory shortage)

Moore law implies this limit should be changed every 1-2 years, and it seems
we forgot doing this for ages.

Even on my old notebook, a process can open 1000000 descriptors without any 
problem.

Signed-off-by: Eric Dumazet <dada1@xxxxxxxxxxxxx>

diff --git a/include/linux/fs.h b/include/linux/fs.h
index b3ec4a4..6253ddd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -21,7 +21,7 @@
 
 /* Fixed constants first: */
 #undef NR_OPEN
-#define NR_OPEN (1024*1024)	/* Absolute upper limit on fd num */
+#define NR_OPEN (16*1024*1024)	/* Absolute upper limit on fd num */
 #define INR_OPEN 1024		/* Initial setting for nfile rlimits */
 
 #define BLOCK_SIZE_BITS 10