Dave Hansen 3cd49fd7da perf: Drop sample rate when sampling is too slow ... commit 14c63f17b1fde5a575a28e96547a22b451c71fb5 upstream. This patch keeps track of how long perf's NMI handler is taking, and also calculates how many samples perf can take a second. If the sample length times the expected max number of samples exceeds a configurable threshold, it drops the sample rate. This way, we don't have a runaway sampling process eating up the CPU. This patch can tend to drop the sample rate down to level where perf doesn't work very well. *BUT* the alternative is that my system hangs because it spends all of its time handling NMIs. I'll take a busted performance tool over an entire system that's busted and undebuggable any day. BTW, my suspicion is that there's still an underlying bug here. Using the HPET instead of the TSC is definitely a contributing factor, but I suspect there are some other things going on. But, I can't go dig down on a bug like that with my machine hanging all the time. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus@samba.org Cc: acme@ghostprotocols.net Cc: Dave Hansen <dave@sr71.net> [ Prettified it a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Weng Meiling <wengmeiling.weng@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2014-06-11 12:03:26 -07:00
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ABI	- Lots of cleanups from Artem, including deletion of some obsolete drivers	2013-05-09 10:15:46 -07:00
DocBook	Documentation: fix DOCBOOKS=... building	2014-06-11 12:03:22 -07:00
EDID	drm: Add 1600x1200 (UXGA) screen resolution to the built-in EDIDs	2013-04-12 14:06:16 +10:00
PCI	…
RCU	Merge commit '8700c95adb03' into timers/nohz	2013-05-02 17:54:19 +02:00
accounting	…
acpi	Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma	2013-05-09 09:46:45 -07:00
aoe	…
arm	ARM: platform specific firmware interfaces for 3.10	2013-05-04 12:33:36 -07:00
arm64	…
auxdisplay	…
backlight	backlight: lp855x: remove duplicate platform data	2013-04-29 18:28:19 -07:00
blackfin	…
block	Documentation: cfq-iosched: update documentation help for cfq tunables	2013-04-09 14:57:06 +02:00
blockdev	…
bus-devices	…
cdrom	…
cgroups	mm, memcg: add rss_huge stat to memory.stat	2013-05-07 18:38:26 -07:00
connector	…
console	…
cpu-freq	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-05 13:23:27 -07:00
cpuidle	cpuidle: make a single register function for all	2013-04-23 13:45:22 +02:00
cris	…
crypto	…
development-process	…
device-mapper	DM RAID: Add message/status support for changing sync action	2013-04-24 11:42:43 +10:00
devicetree	ata: sata_mv: introduce compatible string "marvell, armada-370-sata"	2014-02-06 11:08:15 -08:00
driver-model	…
dvb	…
early-userspace	…
extcon	…
fault-injection	…
fb	…
filesystems	mm, oom: base root bonus on current usage	2014-02-13 13:48:02 -08:00
firmware_class	…
frv	…
hid	…
hwmon	hwmon: (k10temp) Add support for Fam16h (Kabini)	2013-09-07 22:09:59 -07:00
i2c	i2c: i801: enable Intel BayTrail SMBUS	2014-06-07 13:25:35 -07:00
i2o	…
ia64	Fix example error_injection_tool	2013-04-02 09:39:55 -07:00
ide	…
infiniband	…
input	Input: elantech - fix touchpad initialization on Gigabyte U2442	2014-06-07 13:25:36 -07:00
ioctl	USB: cdc-wdm: implement IOCTL_WDM_MAX_COMMAND	2013-03-25 13:32:20 -07:00
isdn	…
ja_JP	Documentation: Update stable address in Chinese and Japanese translations	2014-06-07 13:25:35 -07:00
kbuild	Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild	2013-05-07 07:59:19 -07:00
kdump	Add size restriction to the kdump documentation	2013-04-02 09:40:03 -07:00
ko_KR	…
laptops	…
leds	leds: lp55xx: configure the clock detection	2013-04-01 11:04:53 -07:00
m68k	block: remove refs to XD disks from documentation	2013-05-17 15:17:12 +02:00
make	…
memory-devices	…
metag	…
mips	…
misc-devices	mei: bus: Add device enabling and disabling API	2013-04-08 16:57:15 -07:00
mmc	mmc: core: Add in support to expose PRV for v4 MMCs	2013-03-22 12:10:42 -04:00
mn10300	…
mtd	…
namespaces	…
netlabel	…
networking	packet: fix send path when running with proto == 0	2014-01-15 15:28:46 -08:00
nfc	…
parisc	parisc: document the shadow registers	2013-07-21 18:21:26 -07:00
pcmcia	…
power	PM / hibernate: Correct documentation	2013-05-14 01:58:43 +02:00
powerpc	powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions	2013-06-01 08:29:23 +10:00
pps	…
prctl	…
pti	…
ptp	…
rapidio	rapidio: documentation update for enumeration changes	2013-05-24 16:22:50 -07:00
s390	s390/cio: add condev keyword to cio_ignore	2013-05-02 15:50:20 +02:00
scheduler	…
scsi	[SCSI] qla2xxx: Update copyright dates information in LICENSE.qla2xxx file.	2013-04-06 11:31:30 +01:00
security	Smack: add support for modification of existing rules	2013-03-19 14:16:42 -07:00
serial	…
sh	…
sound	ALSA: hda - Add models for Dell headset jacks	2013-06-17 11:15:56 +02:00
spi	…
sysctl	perf: Drop sample rate when sampling is too slow	2014-06-11 12:03:26 -07:00
target	…
thermal	Thermal: update documentation for thermal_zone_device_register	2013-04-27 09:16:04 +08:00
timers	nohz_full: Add documentation.	2013-04-27 16:41:43 -07:00
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
usb	USB: remove CONFIG_USB_SUSPEND from Documentation	2013-03-28 14:45:56 -07:00
vDSO	…
video4linux	media: media: gspca: sn9c20x: add ID for Genius Look 1320 V2	2014-05-06 07:55:31 -07:00
virtual	Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2013-05-05 14:47:31 -07:00
vm	mm: limit growth of 3% hardcoded other user reserve	2013-04-29 15:54:36 -07:00
w1	…
watchdog	…
wimax	…
x86	Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-04-30 08:35:20 -07:00
xtensa	xtensa: document MMUv3 setup sequence	2013-05-09 01:07:09 -07:00
zh_CN	Documentation: Update stable address in Chinese and Japanese translations	2014-06-07 13:25:35 -07:00
.gitignore	…
00-INDEX	…
BUG-HUNTING	…
Changes	…
CodingStyle	…
DMA-API-HOWTO.txt	…
DMA-API.txt	…
DMA-ISA-LPC.txt	…
DMA-attributes.txt	…
HOWTO	…
IPMI.txt	…
IRQ-affinity.txt	…
IRQ-domain.txt	…
IRQ.txt	…
Intel-IOMMU.txt	…
Makefile	…
ManagementStyle	…
SAK.txt	…
SM501.txt	…
SecurityBugs	…
SubmitChecklist	…
SubmittingDrivers	…
SubmittingPatches	checkpatch: add Suggested-by as a standard signature	2013-04-29 18:28:20 -07:00
VGA-softcursor.txt	…
applying-patches.txt	…
atomic_ops.txt	…
bad_memory.txt	…
basic_profiling.txt	…
bcache.txt	bcache: clarify free/available/unused space	2013-05-15 00:42:52 -07:00
binfmt_misc.txt	…
braille-console.txt	…
bt8xxgpio.txt	…
btmrvl.txt	…
bus-virt-phys-mapping.txt	…
cachetlb.txt	…
circular-buffers.txt	…
clk.txt	clk: add clk_ignore_unused option to keep boot clocks on	2013-04-27 23:03:43 -07:00
coccinelle.txt	Coccinelle: Add support to the SPFLAGS variable	2013-04-08 15:42:03 +02:00
cpu-hotplug.txt	…
cpu-load.txt	…
cputopology.txt	…
crc32.txt	…
dcdbas.txt	…
debugging-modules.txt	…
debugging-via-ohci1394.txt	…
dell_rbu.txt	…
devices.txt	block: remove refs to XD disks from documentation	2013-05-17 15:17:12 +02:00
digsig.txt	…
dma-buf-sharing.txt	dma-buf: replace dma_buf_export() with dma_buf_export_named()	2013-05-01 16:35:36 +05:30
dmaengine.txt	…
dmatest.txt	dmatest: do not allow to interrupt ongoing tests	2013-06-08 02:13:44 +05:30
dontdiff	…
dynamic-debug-howto.txt	…
edac.txt	…
eisa.txt	…
email-clients.txt	…
flexible-arrays.txt	…
futex-requeue-pi.txt	…
gcov.txt	…
gpio.txt	Remove GENERIC_GPIO config option	2013-04-16 18:47:19 +09:00
highuid.txt	…
hw_random.txt	…
hwspinlock.txt	…
init.txt	…
initrd.txt	…
intel_txt.txt	…
io-mapping.txt	…
io_ordering.txt	…
iostats.txt	iostats.txt: add easy-to-find description for field 6	2013-04-29 15:18:50 +02:00
irqflags-tracing.txt	…
isapnp.txt	…
java.txt	…
kernel-doc-nano-HOWTO.txt	…
kernel-docs.txt	…
kernel-parameters.txt	libata: disable a disk via libata.force params	2014-01-09 12:24:23 -08:00
kernel-per-CPU-kthreads.txt	kthread: Document ways of reducing OS jitter due to per-CPU kthreads	2013-04-27 16:52:47 -07:00
kmemcheck.txt	…
kmemleak.txt	…
kobject.txt	…
kprobes.txt	…
kref.txt	…
ldm.txt	…
local_ops.txt	…
lockdep-design.txt	…
lockstat.txt	…
lockup-watchdogs.txt	…
logo.gif	…
logo.txt	…
magic-number.txt	…
md.txt	MD: Fix typos in MD documentation	2013-04-24 11:42:42 +10:00
media-framework.txt	…
memory-barriers.txt	…
memory-hotplug.txt	…
mono.txt	…
mutex-design.txt	…
nommu-mmap.txt	…
numastat.txt	…
oops-tracing.txt	…
padata.txt	…
parport-lowlevel.txt	…
parport.txt	…
percpu-rw-semaphore.txt	…
pi-futex.txt	…
pinctrl.txt	pinctrl: document the "GPIO mode" pitfall	2013-03-18 11:03:29 +01:00
pnp.txt	…
preempt-locking.txt	…
printk-formats.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 13:47:37 -07:00
pwm.txt	…
ramoops.txt	…
rbtree.txt	…
remoteproc.txt	…
rfkill.txt	…
robust-futex-ABI.txt	…
robust-futexes.txt	…
rpmsg.txt	…
rt-mutex-design.txt	…
rt-mutex.txt	…
rtc.txt	…
serial-console.txt	…
sgi-ioc4.txt	…
sgi-visws.txt	…
smsc_ece1099.txt	…
sparse.txt	…
spinlocks.txt	…
stable_api_nonsense.txt	…
stable_kernel_rules.txt	…
static-keys.txt	…
svga.txt	…
sysfs-rules.txt	…
sysrq.txt	Documentation/sysrq: fix inconstistent help message of sysrq key	2013-04-30 17:04:10 -07:00
this_cpu_ops.txt	percpu: add documentation on this_cpu operations	2013-04-04 10:24:53 -07:00
unaligned-memory-access.txt	…
unicode.txt	…
unshare.txt	…
vfio.txt	…
vgaarbiter.txt	…
video-output.txt	…
vme_api.txt	…
volatile-considered-harmful.txt	…
workqueue.txt	…
xz.txt	…
zorro.txt	…