Merge branch 'core/xen' into x86/xen

What:		/sys/firmware/sgi_uv/

Date:		August 2008

Contact:	Russ Anderson <rja@sgi.com>

Description:

		The /sys/firmware/sgi_uv directory contains information

		about the SGI UV platform.

		Under that directory are a number of files:

			partition_id

			coherence_id

		The partition_id entry contains the partition id.

		SGI UV systems can be partitioned into multiple physical

		machines, which each partition running a unique copy

		of the operating system.  Each partition will have a unique

		partition id.  To display the partition id, use the command:

			cat /sys/firmware/sgi_uv/partition_id

		The coherence_id entry contains the coherence id.

		A partitioned SGI UV system can have one or more coherence

		domain.  The coherence id indicates which coherence domain

		this partition is in.  To display the coherence id, use the

		command:

			cat /sys/firmware/sgi_uv/coherence_id

*.css

*.dvi

*.eps

*.fw.gen.S

*.fw

*.gif

*.grep

*.grp

	void (*kill_sb) (struct super_block *);

locking rules:

		may block	BKL

get_sb		yes		yes

kill_sb		yes		yes

get_sb		yes		no

kill_sb		yes		no

->get_sb() returns error or 0 with locked superblock attached to the vfsmount

(exclusive on ->s_umount).

unlocked_ioctl:		no	(see below)

compat_ioctl:		no

mmap:			no

open:			maybe	(see below)

open:			no

flush:			no

release:		no

fsync:			no	(see below)

aio_fsync:		no

fasync:			yes	(see below)

fasync:			no

lock:			yes

readv:			no

writev:			no

semaphore.  Note some filesystems (i.e. remote ones) provide no

protection for i_size so you will need to use the BKL.

->open() locking is in-transit: big lock partially moved into the methods.

The only exception is ->open() in the instances of file_operations that never

end up in ->i_fop/->proc_fops, i.e. ones that belong to character devices

(chrdev_open() takes lock before replacing ->f_op and calling the secondary

method. As soon as we fix the handling of module reference counters all

instances of ->open() will be called without the BKL.

Note: ext2_release() was *the* source of contention on fs-intensive

loads and dropping BKL on ->release() helps to get rid of that (we still

grab BKL for cases when we close a file that had been opened r/w, but that

========

There is plenty of additional information on the linux-ntfs web site

at http://linux-ntfs.sourceforge.net/

at http://www.linux-ntfs.org/

The web site has a lot of additional information, such as a comprehensive

FAQ, documentation on the NTFS on-disk format, information on the Linux-NTFS

For Win2k and later dynamic disks, you can for example use the ldminfo utility

which is part of the Linux LDM tools (the latest version at the time of

writing is linux-ldm-0.0.8.tar.bz2).  You can download it from:

	http://linux-ntfs.sourceforge.net/downloads.html

	http://www.linux-ntfs.org/

Simply extract the downloaded archive (tar xvjf linux-ldm-0.0.8.tar.bz2), go

into it (cd linux-ldm-0.0.8) and change to the test directory (cd test).  You

will find the precompiled (i386) ldminfo utility there.  NOTE: You will not be

"smaps".  When enabled, the contents of these files are visible only to

readers that are allowed to ptrace() the given process.

msgmni

------

Maximum number of message queue ids on the system.

This value scales to the amount of lowmem. It is automatically recomputed

upon memory add/remove or ipc namespace creation/removal.

When a value is written into this file, msgmni's value becomes fixed, i.e. it

is not recomputed anymore when one of the above events occurs.

Use auto_msgmni to change this behavior.

auto_msgmni

-----------

Enables/Disables automatic recomputing of msgmni upon memory add/remove or

upon ipc namespace creation/removal (see the msgmni description above).

Echoing "1" into this file enables msgmni automatic recomputing.

Echoing "0" turns it off.

auto_msgmni default value is 1.

2.4 /proc/sys/vm - The virtual memory subsystem

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