Rik van Riel 34e431b0ae /proc/meminfo: provide estimated available memory ... Many load balancing and workload placing programs check /proc/meminfo to estimate how much free memory is available. They generally do this by adding up "free" and "cached", which was fine ten years ago, but is pretty much guaranteed to be wrong today. It is wrong because Cached includes memory that is not freeable as page cache, for example shared memory segments, tmpfs, and ramfs, and it does not include reclaimable slab memory, which can take up a large fraction of system memory on mostly idle systems with lots of files. Currently, the amount of memory that is available for a new workload, without pushing the system into swap, can be estimated from MemFree, Active(file), Inactive(file), and SReclaimable, as well as the "low" watermarks from /proc/zoneinfo. However, this may change in the future, and user space really should not be expected to know kernel internals to come up with an estimate for the amount of free memory. It is more convenient to provide such an estimate in /proc/meminfo. If things change in the future, we only have to change it in one place. Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Erik Mouw <erik.mouw_2@nxp.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-01-21 16:19:43 -08:00
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caching	FS-Cache: Provide the ability to enable/disable cookies	2013-09-27 18:40:25 +01:00
cifs	cifs: update cifs.txt and remove some outdated infos	2013-09-13 16:29:58 -05:00
configfs	configfs: convert to umode_t	2012-01-03 22:54:57 -05:00
nfs	doc: filesystems : Fix typo in Documentations/filesystems	2013-08-20 13:45:56 +02:00
pohmelfs	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
9p.txt	9p: fix 9p.txt to advertise msize instead of maxdata	2011-10-24 11:13:12 -05:00
00-INDEX	Introduce a new file system, Flash-Friendly File System (F2FS), to Linux 3.8.	2012-12-20 13:54:52 -08:00
adfs.txt	adfs: add hexadecimal filetype suffix option	2011-03-22 17:44:17 -07:00
affs.txt	Documentation: update broken web addresses.	2010-08-04 15:21:40 +02:00
afs.txt
autofs4-mount-control.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
automount-support.txt
befs.txt	Documentation: befs.txt: no maintainer, orphaned	2011-08-13 18:34:03 -07:00
bfs.txt
btrfs.txt	Documentation: filesystems: update btrfs tools section	2013-11-21 11:51:50 -05:00
ceph.txt	ceph: enable/disable dentry complete flags via mount option	2012-01-12 11:00:40 -08:00
coda.txt
cramfs.txt
debugfs.txt	debugfs: more tightly restrict default mount mode	2012-08-27 13:42:02 -07:00
devpts.txt
directory-locking	vfs: take i_mutex on renamed file	2013-11-09 00:16:40 -05:00
dlmfs.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
dnotify_test.c	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
dnotify.txt	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
ecryptfs.txt
efivarfs.txt	efivarfs: Add documentation for the EFI variable filesystem	2012-10-30 10:39:18 +00:00
exofs.txt	exofs: Add option to mount by osdname	2011-03-15 15:02:51 +02:00
ext2.txt
ext3.txt	ext3: allow specifying external journal by pathname mount option	2013-07-31 22:11:15 +02:00
ext4.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-09-06 09:36:28 -07:00
f2fs.txt	f2fs: update f2fs document	2013-11-01 11:20:05 +09:00
fiemap.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
files.txt	Wrap accesses to the fd_sets in struct fdtable	2012-02-19 10:30:52 -08:00
fuse.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
gfs2-glocks.txt	GFS2: Update glock doc to add new stats info	2012-05-10 12:41:40 +01:00
gfs2-uevents.txt	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
gfs2.txt	GFS2: Update main gfs2 doc	2012-05-10 11:45:31 +01:00
hfs.txt	Documentation: HFS is orphaned	2011-11-04 12:01:48 -07:00
hfsplus.txt
hpfs.txt	Documentation/: it's -> its where appropriate	2010-04-23 02:09:52 +02:00
inotify.txt	Documentation: fix inotify source file paths	2011-11-04 12:01:47 -07:00
isofs.txt	Documentation: update broken web addresses.	2010-08-04 15:21:40 +02:00
jfs.txt	doc: fix misspellings with 'codespell' tool	2013-05-28 12:02:12 +02:00
Locking	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-07-03 09:10:19 -07:00
locks.txt	doc: fix broken references	2011-09-27 18:08:04 +02:00
logfs.txt	fix "seperate" typos in comments	2010-05-10 11:56:30 +02:00
Makefile	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
mandatory-locking.txt
ncpfs.txt
nilfs2.txt	nilfs2: remove resize from unsupported features list	2011-07-13 16:08:59 +09:00
ntfs.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
ocfs2.txt	ocfs2: clean up mount option about atime in ocfs2.txt	2011-05-23 23:37:12 -07:00
omfs.txt
path-lookup.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
porting	iget/iget5: don't bother with ->i_lock until we find a match	2013-11-09 00:16:31 -05:00
proc.txt	/proc/meminfo: provide estimated available memory	2014-01-21 16:19:43 -08:00
qnx6.txt	doc: filesystems : Fix typo in Documentations/filesystems	2013-08-20 13:45:56 +02:00
quota.txt
ramfs-rootfs-initramfs.txt	initmpfs: use initramfs if rootfstype= or root= specified	2013-09-11 15:59:38 -07:00
relay.txt	doc: Fix typo in doucmentations	2013-07-25 12:34:15 +02:00
romfs.txt	Documentation/filesystems/romfs.txt: fixing link to genromfs	2011-02-17 22:04:46 +01:00
seq_file.txt	seq_file: use proc_create() in documentation	2009-12-16 07:20:07 -08:00
sharedsubtree.txt	Documentation: Fix trivial typo in filesystems/sharedsubtree.txt	2010-10-25 21:18:21 -04:00
spufs.txt
squashfs.txt	Squashfs: Update documentation to include xattrs	2011-12-30 01:20:24 +00:00
sysfs-pci.txt	PCI: Allow read/write access to sysfs I/O port resources	2010-07-30 09:32:08 -07:00
sysfs-tagging.txt	doc: Fix typo in doucmentations	2013-07-25 12:34:15 +02:00
sysfs.txt	sysfs: propagate umode_t	2012-01-03 22:55:03 -05:00
sysv-fs.txt
tmpfs.txt	mempolicy: document cpuset interaction with tmpfs mpol mount option	2010-05-25 08:06:57 -07:00
ubifs.txt	UBIFS: switch self-check knobs to debugfs	2011-07-04 10:54:28 +03:00
udf.txt
ufs.txt
vfat.txt	Documentation/filesystems/vfat.txt: fix directory entry example	2013-11-13 12:09:32 +09:00
vfs.txt	vfs: improve i_op->atomic_open() documentation	2013-09-16 19:17:24 -04:00
xfs-delayed-logging-design.txt	Fix common misspellings	2011-03-31 11:26:23 -03:00
xfs-self-describing-metadata.txt	xfs: add metadata CRC documentation	2013-04-27 13:27:43 -05:00
xfs.txt	doc: filesystems : Fix typo in Documentations/filesystems	2013-08-20 13:45:56 +02:00
xip.txt