linux/include
Dave Hansen 5509a5d27b drop_caches: add some documentation and info message
There is plenty of anecdotal evidence and a load of blog posts
suggesting that using "drop_caches" periodically keeps your system
running in "tip top shape".  Perhaps adding some kernel documentation
will increase the amount of accurate data on its use.

If we are not shrinking caches effectively, then we have real bugs.
Using drop_caches will simply mask the bugs and make them harder to
find, but certainly does not fix them, nor is it an appropriate
"workaround" to limit the size of the caches.  On the contrary, there
have been bug reports on issues that turned out to be misguided use of
cache dropping.

Dropping caches is a very drastic and disruptive operation that is good
for debugging and running tests, but if it creates bug reports from
production use, kernel developers should be aware of its use.

Add a bit more documentation about it, a syslog message to track down
abusers, and vmstat drop counters to help analyze problem reports.

[akpm@linux-foundation.org: checkpatch fixes]
[hannes@cmpxchg.org: add runtime suppression control]
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:04 -07:00
..
acpi More ACPI and power management updates for 3.15-rc1 2014-04-02 14:10:21 -07:00
asm-generic Devicetree changes for v3.15 2014-04-02 14:27:15 -07:00
clocksource
crypto crypto: export NULL algorithms defines 2014-03-21 21:54:26 +08:00
drm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-04-02 16:23:38 -07:00
dt-bindings Char/Misc driver patches for 3.15-rc1 2014-04-01 16:13:21 -07:00
keys
kvm ARM: KVM: fix non-VGIC compilation 2014-03-06 09:47:42 +01:00
linux drop_caches: add some documentation and info message 2014-04-03 16:21:04 -07:00
math-emu
media [media] of: move common endpoint parsing to drivers/of 2014-03-06 17:41:48 +01:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
pcmcia
ras
rdma IB: Report using RoCE IP based gids in port caps 2014-02-13 14:46:03 -08:00
rxrpc
scsi SCSI misc on 20140401 2014-04-01 18:49:04 -07:00
sound ASoC: Final updates for v3.15 merge window 2014-03-31 12:33:09 +02:00
target iscsi/iser-target: Fix isert_conn->state hung shutdown issues 2014-03-04 17:54:09 -08:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-04-02 20:53:45 -07:00
video x86, platforms: Remove SGI Visual Workstation 2014-02-27 08:07:39 -08:00
xen Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2014-02-14 10:45:18 -08:00
Kbuild