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
..
ABI	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-04-02 20:53:45 -07:00
accounting
acpi	ACPI and power management updates for 3.14-rc1	2014-01-24 15:51:02 -08:00
aoe
arm	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
arm64	arm64: Extend the PCI I/O space to 16MB	2014-02-26 11:16:27 +00:00
auxdisplay
backlight
blackfin	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
block	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
blockdev	drbd: Describe the future high-level structure of DRBD	2014-02-17 16:27:48 +01:00
bus-devices
cdrom
cgroups	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media	2014-01-31 09:31:14 -08:00
connector	connector: add portid to unicast in addition to broadcasting	2014-02-07 15:40:17 -08:00
console
cpu-freq	cpufreq: Add stop CPU callback to cpufreq_driver interface	2014-03-20 03:50:12 +01:00
cpuidle
cris
crypto
development-process
device-mapper	dm thin: fix Documentation for held metadata root feature	2014-03-06 14:23:35 -05:00
devicetree	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-04-02 20:53:45 -07:00
DocBook	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-04-02 20:53:45 -07:00
driver-model	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2014-01-22 21:21:55 -08:00
dvb	[media] update Michael Krufky's email address	2014-02-04 06:34:21 -02:00
early-userspace
EDID
extcon	extcon: fix switch class porting guide (Documentation)	2014-01-07 11:54:28 +09:00
fault-injection
fb	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
filesystems	mm + fs: store shadow entries in page cache	2014-04-03 16:21:01 -07:00
firmware_class
fmc	FMC: make eeprom attribute writable	2014-02-28 15:12:08 -08:00
frv
gpio	gpiolib: return -ENOENT if no GPIO mapping exists	2013-12-12 19:33:59 +01:00
hid	HID: uhid: Add UHID_CREATE2 + UHID_INPUT2	2014-04-01 18:27:33 +02:00
hwmon	hwmon: (pmbus/ltc2978) Add support for LTM4676	2014-03-19 18:59:40 -07:00
i2c	Documentation: i2c: mention ACPI method for instantiating devices	2014-02-15 19:46:34 +01:00
i2o
ia64
ide	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
infiniband
input	doc: fix double words	2014-03-21 13:16:58 +01:00
ioctl	s390/hypfs: add interface for diagnose 0x304	2014-01-24 09:40:59 +01:00
isdn
ja_JP	Documentation: ja_JP: Update broken link to tpp	2013-12-10 23:09:08 -08:00
kbuild
kdump
ko_KR	Documentation: HOWTO: Updates on subsystem trees, patchwork, -next (vs. -mm) in ko_KR	2014-01-08 15:32:51 -08:00
laptops	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
leds	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
m68k	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
make
memory-devices
metag
mic	misc: mic: Fix endianness issues.	2013-11-27 11:03:38 -08:00
mips
misc-devices	Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging	2014-01-29 18:56:27 -08:00
mmc
mn10300
mtd	mtd: nand: pxa3xx: Add documentation about the controller	2014-01-03 11:22:09 -08:00
namespaces
netlabel
networking	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-04-02 20:53:45 -07:00
nfc
parisc
PCI	Merge branch 'pci/dead-code' into next	2014-02-20 14:32:34 -07:00
pcmcia
phy	phy: Add new Exynos USB 2.0 PHY driver	2014-03-08 12:39:44 +05:30
power	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2014-04-02 16:23:38 -07:00
powerpc
pps
prctl
pti
ptp	ptp: Fix compiler warnings in the testptp utility	2014-03-27 14:51:47 -04:00
rapidio
RCU	documentation: Fix some inconsistencies in RTFP.txt	2014-02-17 14:56:10 -08:00
s390	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
scheduler	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
scsi	[SCSI] megaraid_sas: Version and Changelog update	2014-03-15 10:19:21 -07:00
security	doc: fix double words	2014-03-21 13:16:58 +01:00
serial	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
sh
sound	x86, platforms: Remove SGI Visual Workstation	2014-02-27 08:07:39 -08:00
spi	Merge remote-tracking branches 'spi/topic/s3c64xx', 'spi/topic/sc18is602', 'spi/topic/sh-hspi', 'spi/topic/sh-msiof', 'spi/topic/sh-sci', 'spi/topic/sirf' and 'spi/topic/spidev' into spi-next	2014-03-30 00:51:34 +00:00
sysctl	drop_caches: add some documentation and info message	2014-04-03 16:21:04 -07:00
target
thermal
timers	Documentation/: update 00-INDEX files	2014-02-10 16:01:40 -08:00
tpm
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2014-04-02 16:23:38 -07:00
usb	doc: fix double words	2014-03-21 13:16:58 +01:00
vDSO
video4linux	[media] sn9c102: prepare for removal by moving it to staging	2013-12-20 13:41:36 -02:00
virtual	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2014-04-02 16:23:38 -07:00
vm	doc: fix double words	2014-03-21 13:16:58 +01:00
w1	Merge 3.14-rc3 into char-misc-next	2014-02-18 08:09:40 -08:00
watchdog	watchdog: it87_wdt: Work around non-working CIR interrupts	2014-03-31 13:33:55 +02:00
wimax
x86	x86, boot: Correct max ramdisk size name	2014-03-13 15:32:42 -07:00
xtensa	xtensa: remap io area defined in device tree	2014-01-15 00:25:14 +04:00
zh_CN	Documentation:Update Documentation/zh_CN/arm64/memory.txt	2014-02-07 15:24:31 -08:00
.gitignore
00-INDEX	Merge branch 'x86-nuke-platforms-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2014-04-02 13:15:58 -07:00
applying-patches.txt
assoc_array.txt	KEYS: Fix multiple key add into associative array	2013-12-02 11:24:18 +00:00
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
bcache.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
Changes	remove obsolete references to powertweak	2013-11-27 20:34:32 -08:00
circular-buffers.txt	documentation: Update circular buffer for load-acquire/store-release	2013-12-03 10:08:57 -08:00
clk.txt	clk: Add set_rate_and_parent() op	2014-01-16 12:00:57 -08:00
coccinelle.txt
CodingStyle
cpu-hotplug.txt	Documentation/cpu-hotplug.txt: fix a typo in example code	2014-01-23 16:37:01 -08:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	firewire: Enable remote DMA above 4 GB	2014-01-20 01:11:13 +01:00
dell_rbu.txt
devices.txt	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2014-04-02 20:53:45 -07:00
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt
dma-buf-sharing.txt
DMA-ISA-LPC.txt
dmaengine.txt
dmatest.txt	dmatest: add a 'wait' parameter	2013-11-14 11:04:40 -08:00
dontdiff
dynamic-debug-howto.txt	dynamic-debug-howto.txt: update since new wildcard support	2014-01-23 16:36:55 -08:00
edac.txt
efi-stub.txt	doc: Fix trivial spelling mistake in efi-stub.txt	2013-12-19 15:09:14 +01:00
eisa.txt
email-clients.txt	doc: fix some typos	2013-12-02 14:48:28 +01:00
flexible-arrays.txt
futex-requeue-pi.txt	doc: fix double words	2014-03-21 13:16:58 +01:00
gcov.txt
highuid.txt
HOWTO	Documentation: HOWTO: Update broken links to tpp	2013-12-10 23:09:08 -08:00
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt	doc: fix some typos	2013-12-02 14:48:28 +01:00
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt	doc: fix some typos	2013-12-02 14:48:28 +01:00
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt	More ACPI and power management updates for 3.15-rc1	2014-04-02 14:10:21 -07:00
kernel-per-CPU-kthreads.txt	Documentation/kernel-per-CPU-kthreads.txt: Workqueue affinity	2014-02-17 14:56:08 -08:00
kmemcheck.txt	doc: fix double words	2014-03-21 13:16:58 +01:00
kmemleak.txt	kmemleak: allow freeing internal objects after kmemleak was disabled	2014-04-03 16:20:50 -07:00
kobject.txt	kobject: remove kset from sysfs immediately in kset_unregister()	2013-12-07 21:20:11 -08:00
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
lockup-watchdogs.txt
logo.gif
logo.txt
magic-number.txt
Makefile
ManagementStyle
md.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
media-framework.txt
memory-barriers.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2014-04-02 16:23:38 -07:00
memory-hotplug.txt
module-signing.txt	doc: Insert MODULE_ in module-signing macros	2014-02-20 14:55:04 +01:00
mono.txt
mutex-design.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt	drivers: phy: Add support for optional phys	2014-02-05 05:48:43 +00:00
pi-futex.txt
pinctrl.txt	pinctrl: Fix some typos and grammar issues in the documentation	2014-01-15 13:59:50 +01:00
pnp.txt
preempt-locking.txt
printk-formats.txt	vsprintf: add %pad extension for dma_addr_t use	2014-01-23 16:36:56 -08:00
pwm.txt
ramoops.txt
rbtree.txt
remoteproc.txt
rfkill.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
robust-futex-ABI.txt	Documentation/robust-futex-API: Count properly to 4	2013-11-30 14:08:28 +01:00
robust-futexes.txt
rpmsg.txt
rt-mutex-design.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt
static-keys.txt	doc: fix some typos in documentations	2013-12-02 14:45:19 +01:00
SubmitChecklist
SubmittingDrivers
SubmittingPatches
svga.txt
sysfs-rules.txt
sysrq.txt
this_cpu_ops.txt
unaligned-memory-access.txt	ether_addr_equal: Optimize implementation, remove unused compare_ether_addr	2013-12-06 16:37:43 -05:00
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt	VME: Rename vme_slot_get to avoid confusion with reference counting	2013-12-03 11:15:58 -08:00
volatile-considered-harmful.txt
workqueue.txt
ww-mutex-design.txt
xz.txt
zorro.txt	zorro/UAPI: Disintegrate include/linux/zorro*.h	2013-11-26 11:09:08 +01:00