linux/Documentation
Vivek Goyal bdc85df7a8 blk-cgroup: Allow creation of hierarchical cgroups
o Allow hierarchical cgroup creation for blkio controller

o Currently we disallow it as both the io controller policies (throttling
  as well as proportion bandwidth) do not support hierarhical accounting
  and control. But the flip side is that blkio controller can not be used with
  libvirt as libvirt creates a cgroup hierarchy deeper than 1 level.

  <top-level-cgroup-dir>/<controller>/libvirt/qemu/<virtual-machine-groups>

o So this patch will allow creation of cgroup hierarhcy but at the backend
  everything will be treated as flat. So if somebody created a an hierarchy
  like as follows.

			root
			/  \
		     test1 test2
			|
		     test3

  CFQ and throttling will practically treat all groups at same level.

				pivot
			     /  |   \  \
			root  test1 test2  test3

o Once we have actual support for hierarchical accounting and control
  then we can introduce another cgroup tunable file "blkio.use_hierarchy"
  which will be 0 by default but if user wants to enforce hierarhical
  control then it can be set to 1. This way there should not be any
  ABI problems down the line.

o The only not so pretty part is introduction of extra file "use_hierarchy"
  down the line. Kame-san had mentioned that hierarhical accounting is
  expensive in memory controller hence they keep it off by default. I
  suspect same will be the case for IO controller also as for each IO
  completion we shall have to account IO through hierarchy up to the root.
  if yes, then it probably is not a very bad idea to introduce this extra
  file so that it will be used only when somebody needs it and some people
  might enable hierarchy only in part of the hierarchy.

o This is how basically memory controller also uses "use_hierarhcy" and
  they also allowed creation of hierarchies when actual backend support
  was not available.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Reviewed-by: Ciju Rajan K <ciju@linux.vnet.ibm.com>
Tested-by: Ciju Rajan K <ciju@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-15 19:37:36 +01:00
..
ABI oom: document obsolete oom_adj tunable 2010-11-12 07:55:31 -08:00
accounting delay-accounting: reimplement -c for getdelays.c to report information on a target command 2010-10-27 18:03:17 -07:00
acpi ACPI: introduce module parameter acpi.aml_debug_output 2010-08-14 23:02:14 -04:00
aoe Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
arm Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-10-24 13:41:39 -07:00
auxdisplay
blackfin Blackfin: document SPI CS limitations with CPHA=0 2010-08-06 12:55:52 -04:00
block Documentation: remove anticipatory scheduler info 2010-11-11 12:09:59 +01:00
blockdev Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
cdrom Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
cgroups blk-cgroup: Allow creation of hierarchical cgroups 2010-11-15 19:37:36 +01:00
connector
console
cpu-freq
cpuidle
cris
crypto
development-process Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
device-mapper Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
DocBook Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb 2010-10-29 11:49:38 -07:00
driver-model
dvb [media] lmedm04: driver for DM04/QQBOX updated to version 1.60 2010-10-22 22:22:47 -02:00
early-userspace
fault-injection
fb Merge branch 'viafb-next' of git://github.com/schandinat/linux-2.6 2010-10-27 19:02:41 -07:00
filesystems xfs: remove experimental tag from the delaylog option 2010-11-10 12:00:47 -06:00
firmware_class firmware: Update hotplug script 2010-08-05 13:53:34 -07:00
frv
hwmon hwmon: (it87) Add support for the IT8721F/IT8758E 2010-10-28 20:31:51 +02:00
i2c i2c-i801: Add PCI idents for Patsburg 'IDF' SMBus controllers 2010-10-31 21:07:00 +01:00
i2o
ia64 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
ide
infiniband Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
input HID: ntrig: add documention 2010-08-30 15:25:18 +02:00
ioctl Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 2010-10-28 12:13:00 -07:00
isdn Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-08-04 15:31:02 -07:00
ja_JP Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kbuild Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2010-10-28 16:18:59 -07:00
kdump
ko_KR Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kvm KVM: Document that KVM_GET_SUPPORTED_CPUID may return emulated values 2010-10-24 10:52:48 +02:00
laptops thinkpad-acpi: untangle ACPI/vendor backlight selection 2010-08-16 11:54:50 -04:00
leds Documentation: led drivers lp5521 and lp5523 2010-11-12 07:55:32 -08:00
lguest Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier 2010-10-19 09:13:04 +02:00
m68k
make
mips
misc-devices Documentation: short descriptions for bh1770glc and apds990x drivers 2010-10-26 16:52:14 -07:00
mmc mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
mn10300
mtd Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
namespaces
netlabel
networking docs: Add neigh/gc_thresh3 and route/max_size documentation. 2010-11-12 14:03:20 -08:00
parisc
PCI Documentation: pci.txt: fix typo 2010-07-11 22:17:45 +02:00
pcmcia pcmcia: use autoconfiguration feature for ioports and iomem 2010-09-29 17:20:24 +02:00
power PM: Introduce library for device-specific OPPs (v7) 2010-10-17 01:57:50 +02:00
powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-10-22 20:30:48 -07:00
pps
prctl
RCU rcu: Add tracing data to support queueing models 2010-09-23 09:16:53 -07:00
s390 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
scheduler
scsi [SCSI] megaraid_sas: Version and documentation update 2010-10-26 11:11:12 -05:00
serial Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
sh
sound Merge branch 'topic/hda' into for-linus 2010-10-25 10:40:05 +02:00
sparc
spi spi/ep93xx: implemented driver for Cirrus EP93xx SPI controller 2010-05-25 00:23:16 -06:00
sysctl Restrict unprivileged access to kernel syslog 2010-11-12 07:55:32 -08:00
telephony Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
thermal
timers Documentation/timers/hpet_example.c: add supporting info for hpet_example 2010-10-26 16:52:11 -07:00
trace tracing, vmscan: add trace events for LRU list shrinking 2010-10-26 16:52:07 -07:00
uml Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
usb USB: teach "devices" file about Wireless and SuperSpeed USB 2010-10-22 10:21:40 -07:00
video4linux [media] Support for Elgato Video Capture 2010-10-22 20:55:43 -02:00
vm mm: highmem documentation 2010-10-26 16:52:08 -07:00
w1 Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
watchdog watchdog: docs: add an entry for imx2_wdt 2010-07-01 16:02:55 +00:00
wimax
x86 Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-22 08:54:21 -07:00
zh_CN Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
.gitignore
00-INDEX mmc: add erase, secure erase, trim and secure trim operations 2010-08-12 08:43:30 -07:00
apparmor.txt AppArmor: update Maintainer and Documentation 2010-08-02 15:35:15 +10:00
applying-patches.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt documentation: fix almost duplicate filenames (IO/io-mapping.txt) 2010-07-20 17:49:30 +00:00
cachetlb.txt
Changes Documentation update broken web addresses 2010-07-11 21:55:42 +02:00
circular-buffers.txt
coccinelle.txt Coccinelle: Fix documentation 2010-10-28 00:32:23 +02:00
CodingStyle
cpu-hotplug.txt documentation: fix erroneous email address. 2010-08-11 23:04:10 +09:30
cpu-load.txt
cputopology.txt topology/sysfs: Provide book id and siblings attributes 2010-09-09 20:41:25 +02:00
credentials.txt CRED: Fix __task_cred()'s lockdep check and banner comment 2010-07-29 15:16:18 -07:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2010-10-28 09:35:11 -07:00
DMA-API-HOWTO.txt Documentation: DMA-API-HOWTO.txt: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN 2010-08-14 11:56:46 -07:00
DMA-API.txt dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
DMA-attributes.txt
DMA-ISA-LPC.txt
dmaengine.txt
dontdiff
dynamic-debug-howto.txt Dynamic Debug: Introduce ddebug_query= boot parameter 2010-10-22 10:16:42 -07:00
edac.txt Documentation/edac.txt: Reflect the sysfs changes at the document 2010-05-10 11:49:30 -03:00
eisa.txt
email-clients.txt
feature-removal-schedule.txt Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2010-10-28 09:35:11 -07:00
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
gpio.txt gpio: doc updates 2010-09-09 18:57:24 -07:00
highuid.txt
HOWTO Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
hw_random.txt
init.txt
initrd.txt
intel_txt.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt docbook: warn on unused doc entries 2010-09-11 16:49:21 -07:00
kernel-docs.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
kernel-parameters.txt Documentation: remove anticipatory scheduler info 2010-11-11 12:09:59 +01:00
keys-request-key.txt
keys.txt
kmemcheck.txt
kmemleak.txt
kobject.txt
kprobes.txt kprobes: Update document about irq disabled state in kprobe handler 2010-10-14 08:55:27 +02:00
kref.txt
ldm.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
leds-class.txt led-class: always implement blinking 2010-11-12 07:55:32 -08:00
leds-lp3944.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
logo.gif
logo.txt
magic-number.txt
Makefile
ManagementStyle
mca.txt
md.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
memory-barriers.txt
memory-hotplug.txt
memory.txt
mono.txt
mutex-design.txt mutex: Fix annotations to include it in kernel-locking docbook 2010-09-03 08:19:51 +02:00
nmi_watchdog.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I') 2010-05-19 08:37:43 +01:00
padata.txt Documentation/padata.txt: fix typos etc. 2010-08-11 08:59:18 -07:00
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt
preempt-locking.txt
printk-formats.txt
prio_tree.txt
rbtree.txt Documentation: remove anticipatory scheduler info 2010-11-11 12:09:59 +01:00
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rt-mutex-design.txt variable name fix to Documentation/rt-mutex-design.txt 2010-06-05 17:39:09 +02:00
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
SELinux.txt
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt
Smack.txt
sparse.txt update email address 2010-07-19 10:56:54 +02:00
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt
SubmitChecklist Documentation: update SubmitChecklist for O=objdir and kconfig testing 2010-05-24 07:31:20 -07:00
SubmittingDrivers Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
SubmittingPatches SubmittingPatches: add more about patch descriptions 2010-08-09 20:45:05 -07:00
svga.txt
sysfs-rules.txt
sysrq.txt documentation: update sysrq.txt magic sysrq keys 2010-10-26 17:32:41 -07:00
tomoyo.txt TOMOYO: Update version to 2.3.0 2010-08-02 15:35:10 +10:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
volatile-considered-harmful.txt
workqueue.txt workqueue: add and use WQ_MEM_RECLAIM flag 2010-10-11 15:20:26 +02:00
zorro.txt