Commit 9cfe015a authored by Eric Dumazet's avatar Eric Dumazet Committed by Linus Torvalds
Browse files

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.

[akpm@linux-foundation.org: export it for sparc64]
Signed-off-by: default avatarEric Dumazet <dada1@cosmosbay.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 774ed22c

Documentation/filesystems/proc.txt

+8 −0
Original line number Diff line number Diff line
@@ -1029,6 +1029,14 @@ nr_inodes 
Denotes the  number  of  inodes the system has allocated. This number will

grow and shrink dynamically.



nr_open

-------



Denotes the maximum number of file-handles a process can

allocate. Default value is 1024*1024 (1048576) which should be

enough for most machines. Actual limit depends on RLIMIT_NOFILE

resource limit.



nr_free_inodes

--------------

Documentation/sysctl/fs.txt

+10 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ Currently, these files are in /proc/sys/fs: 
- inode-max

- inode-nr

- inode-state

- nr_open

- overflowuid

- overflowgid

- suid_dumpable
@@ -91,6 +92,15 @@ usage of file handles and you don't need to increase the maximum. 


==============================================================



nr_open:



This denotes the maximum number of file-handles a process can

allocate. Default value is 1024*1024 (1048576) which should be

enough for most machines. Actual limit depends on RLIMIT_NOFILE

resource limit.



==============================================================



inode-max, inode-nr & inode-state:



As with file handles, the kernel allocates the inode structures

arch/alpha/kernel/osf_sys.c

+1 −1
Original line number Diff line number Diff line
@@ -430,7 +430,7 @@ sys_getpagesize(void) 
asmlinkage unsigned long

sys_getdtablesize(void)

{

	return NR_OPEN;

	return sysctl_nr_open;

}



/*

arch/mips/kernel/sysirix.c

+1 −1
Original line number Diff line number Diff line
@@ -356,7 +356,7 @@ asmlinkage int irix_syssgi(struct pt_regs *regs) 
			retval = NGROUPS_MAX;

			goto out;

		case 5:

			retval = NR_OPEN;

			retval = sysctl_nr_open;

			goto out;

		case 6:

			retval = 1;

arch/sparc64/kernel/sparc64_ksyms.c

+1 −0
Original line number Diff line number Diff line
@@ -277,6 +277,7 @@ EXPORT_SYMBOL(sys_getpid); 
EXPORT_SYMBOL(sys_geteuid);

EXPORT_SYMBOL(sys_getuid);

EXPORT_SYMBOL(sys_getegid);

EXPORT_SYMBOL(sysctl_nr_open);

EXPORT_SYMBOL(sys_getgid);

EXPORT_SYMBOL(svr4_getcontext);

EXPORT_SYMBOL(svr4_setcontext);

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