Tejun Heo 969c79215a sched: replace migration_thread with cpu_stop ... Currently migration_thread is serving three purposes - migration pusher, context to execute active_load_balance() and forced context switcher for expedited RCU synchronize_sched. All three roles are hardcoded into migration_thread() and determining which job is scheduled is slightly messy. This patch kills migration_thread and replaces all three uses with cpu_stop. The three different roles of migration_thread() are splitted into three separate cpu_stop callbacks - migration_cpu_stop(), active_load_balance_cpu_stop() and synchronize_sched_expedited_cpu_stop() - and each use case now simply asks cpu_stop to execute the callback as necessary. synchronize_sched_expedited() was implemented with private preallocated resources and custom multi-cpu queueing and waiting logic, both of which are provided by cpu_stop. synchronize_sched_expedited_count is made atomic and all other shared resources along with the mutex are dropped. synchronize_sched_expedited() also implemented a check to detect cases where not all the callback got executed on their assigned cpus and fall back to synchronize_sched(). If called with cpu hotplug blocked, cpu_stop already guarantees that and the condition cannot happen; otherwise, stop_machine() would break. However, this patch preserves the paranoid check using a cpumask to record on which cpus the stopper ran so that it can serve as a bisection point if something actually goes wrong theree. Because the internal execution state is no longer visible, rcu_expedited_torture_stats() is removed. This patch also renames cpu_stop threads to from "stopper/%d" to "migration/%d". The names of these threads ultimately don't matter and there's no reason to make unnecessary userland visible changes. With this patch applied, stop_machine() and sched now share the same resources. stop_machine() is faster without wasting any resources and sched migration users are much cleaner. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Josh Triplett <josh@freedesktop.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Dimitri Sivanich <sivanich@sgi.com>		2010-05-06 18:49:21 +02:00
..
ABI	USB: Fix documentation for avoid_reset_quirk	2010-03-19 07:24:11 -07:00
accounting
acpi	ACPI: support customizing ACPI control methods at runtime	2009-12-11 01:50:08 -05:00
aoe
arm	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2010-03-12 16:04:50 -08:00
auxdisplay	includecheck fix: Documentation, cfag12864b-example.c	2009-09-24 07:20:57 -07:00
blackfin	Blackfin: add an example showing how to use the gptimers API	2009-12-15 00:15:04 -05:00
block	Documentation: fix block/biodoc.txt dma mapping description	2010-03-08 09:11:07 +01:00
blockdev	The DRBD driver	2009-10-01 21:17:49 +02:00
cdrom	ide: doc: remove compilation options section from ide-cd documentation	2009-12-13 20:41:53 -08:00
cgroups	memcg: fix typo in memcg documentation	2010-03-24 16:31:20 -07:00
connector	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
console	doc: fix console doc typo	2010-02-24 13:51:32 +01:00
cpu-freq	[CPUFREQ] Processor Clocking Control interface driver	2010-01-13 10:55:16 -05:00
cpuidle
cris
crypto
development-process
device-mapper	dm: document when snapshot has finished merging	2010-03-06 02:29:56 +00:00
DocBook	Merge branch 'master' into for-linus	2010-03-19 08:05:10 +01:00
driver-model	Fix spelling of 'platform' in comments and doc	2010-02-05 12:22:34 +01:00
dvb	V4L/DVB: get_dvb_firmware: Fix typo, sort list of components	2010-02-26 15:10:56 -03:00
early-userspace
fault-injection	lkdtm: add debugfs access and loosen KPROBE ties	2010-03-06 11:26:32 -08:00
fb	fbdev: rename imacfb.txt to efifb.txt and change imacfb to efifb.	2010-04-07 08:38:02 -07:00
filesystems	9p: documentation update	2010-04-05 10:37:36 -05:00
firmware_class
frv
hwmon	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
i2c	i2c: Document the message size limit	2010-03-02 12:23:49 +01:00
i2o
ia64
ide
infiniband	IB: Fix typo in ipoib.txt	2009-12-09 14:21:36 -08:00
input	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
ioctl	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client	2010-03-19 09:43:06 -07:00
isdn	gigaset: small documentation improvement	2010-02-26 01:24:22 -08:00
ja_JP
kbuild	kbuild: generate modules.builtin	2009-12-12 13:08:16 +01:00
kdump
ko_KR
kvm	KVM: trivial document fixes	2010-03-01 12:35:43 -03:00
laptops	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2010-03-12 16:04:50 -08:00
lguest	lguest: remove unneeded zlib.h include in example launcher	2010-02-24 14:22:22 +10:30
m68k
make
mips
misc-devices	ad525x_dpot: new driver for AD525x digital potentiometers	2009-12-15 08:53:25 -08:00
mn10300
mtd
namespaces
netlabel
networking	net: corrected documentation for hardware time stamping	2010-04-07 21:52:07 -07:00
parisc
PCI	Documentation: rename PCI/PCI-DMA-mapping.txt to DMA-API-HOWTO.txt	2010-03-24 16:31:20 -07:00
pcmcia	pcmcia: use ops_mutex for rsrc_{mgr,nonstatic} locking	2010-02-17 17:48:24 +01:00
power	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
powerpc	powerpc/fsl: add device tree binding for QE firmware	2010-03-26 22:09:57 -06:00
pps
prctl
RCU	sched: replace migration_thread with cpu_stop	2010-05-06 18:49:21 +02:00
s390	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
scheduler	sched: Remove USER_SCHED from documentation	2010-04-02 20:12:01 +02:00
scsi	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
serial	ldisc: new dcd_change() method for line disciplines	2010-03-12 15:52:43 -08:00
sh
sound	ALSA: hda - Update document about MSI and interrupts	2010-04-01 18:08:29 +02:00
sparc
spi	tree-wide: fix assorted typos all over the place	2009-12-04 15:39:55 +01:00
sysctl	memcg: handle panic_on_oom=always case	2010-03-12 15:52:37 -08:00
telephony
thermal	thermal: add sanity check for the passive attribute	2009-11-05 18:18:10 -05:00
timers	Documentation/timers/: split txt and source files	2010-03-12 15:52:35 -08:00
trace	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
uml
usb	USB: convert to the runtime PM framework	2010-03-02 14:54:12 -08:00
video4linux	V4L/DVB: Documentation: gspca.txt: update known mr97310a cams	2010-02-26 15:11:09 -03:00
vm	Documentation/vm/: split txt and source files	2010-03-12 15:52:35 -08:00
w1	ds2482: Discard obsolete detect method	2009-10-04 22:53:41 +02:00
watchdog	[WATCHDOG] doc: Fix use of WDIOC_SETOPTIONS ioctl.	2010-04-06 14:23:55 +00:00
wimax
x86	x86, numa: Remove configurable node size support for numa emulation	2010-02-15 14:34:18 -08:00
zh_CN
00-INDEX
applying-patches.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
cachetlb.txt	Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm	2010-03-01 09:15:15 -08:00
Changes	netfilter: xtables: document minimal required version	2009-12-14 14:52:10 +01:00
circular-buffers.txt	Document Linux's circular buffering capabilities	2010-03-24 16:31:22 -07:00
CodingStyle
cpu-hotplug.txt	cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt	2009-12-17 11:43:29 +10:30
cpu-load.txt
cputopology.txt	Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files	2009-10-30 14:59:52 -07:00
credentials.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt	ieee1394: update URLs in debugging-via-ohci1394.txt	2009-10-03 09:28:11 +02:00
dell_rbu.txt
devices.txt
DMA-API-HOWTO.txt	Documentation: rename PCI/PCI-DMA-mapping.txt to DMA-API-HOWTO.txt	2010-03-24 16:31:20 -07:00
DMA-API.txt	Documentation: rename PCI-DMA-mapping.txt to DMA-API-HOWTO.txt	2010-03-12 15:52:43 -08:00
DMA-attributes.txt
DMA-ISA-LPC.txt
dmaengine.txt
dontdiff	Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-kconfig	2010-02-25 14:43:57 -08:00
dynamic-debug-howto.txt
edac.txt	fix typos/grammos in Documentation/edac.txt	2009-12-04 15:39:53 +01:00
eisa.txt	doc: fix Defaultd -> Defaults typo in EISA doc	2010-02-05 12:22:39 +01:00
email-clients.txt	Documentation/email-clients.txt: update gmail information	2010-03-12 15:52:35 -08:00
feature-removal-schedule.txt	ACPI: plan to delete "acpi=ht" boot option	2010-03-14 20:58:24 -04:00
flexible-arrays.txt	Update flex_arrays.txt	2009-10-15 07:25:20 -06:00
futex-requeue-pi.txt
gcov.txt
gpio.txt	gpio: introduce gpio_request_one() and friends	2010-03-06 11:26:48 -08:00
highuid.txt
HOWTO	HOWTO: Updates on subsystem trees, patchwork, -next (vs. -mm)	2010-03-07 17:04:49 -08:00
hw_random.txt
init.txt	init/main.c: improve usability in case of init binary failure	2010-03-06 11:26:29 -08:00
initrd.txt
intel_txt.txt
Intel-IOMMU.txt
io_ordering.txt
io-mapping.txt
IO-mapping.txt	Documentation: fix ioremap return type	2010-01-02 10:09:44 -08:00
iostats.txt
IPMI.txt	ipmi: add parameter to limit CPU usage in kipmid	2010-03-12 15:52:39 -08:00
IRQ-affinity.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt	documentation: update kernel-doc-nano-HOWTO information	2010-01-11 09:34:07 -08:00
kernel-docs.txt
kernel-parameters.txt	ACPI: processor: remove early _PDC optin quirks	2010-03-14 21:17:21 -04:00
keys-request-key.txt
keys.txt
kmemcheck.txt
kmemleak.txt
kobject.txt	kobject: documentation: Update to refer to kset-example.c.	2010-03-19 07:12:20 -07:00
kprobes.txt	kprobes: Add documents of jump optimization	2010-02-25 17:49:27 +01:00
kref.txt
ldm.txt
leds-class.txt
leds-lp3944.txt
local_ops.txt
lockdep-design.txt
lockstat.txt	lockstat: Add usage info to Documentation/lockstat.txt	2009-12-06 13:20:02 +01:00
logo.gif
logo.txt
magic-number.txt
Makefile	Documentation/fs/: split txt and source files	2010-03-12 15:52:35 -08:00
ManagementStyle
mca.txt
md.txt	md: add 'recovery_start' per-device sysfs attribute	2009-12-14 12:58:57 +11:00
memory-barriers.txt	Document Linux's circular buffering capabilities	2010-03-24 16:31:22 -07:00
memory-hotplug.txt	mm: add numa node symlink for memory section in sysfs	2009-12-15 08:53:17 -08:00
memory.txt
mono.txt
mutex-design.txt
nmi_watchdog.txt
nommu-mmap.txt	nommu: fix malloc performance by adding uninitialized flag	2009-12-15 08:53:24 -08:00
numastat.txt
oops-tracing.txt	docs: Describe the 'C' taint flag in oops-tracing.txt	2009-11-09 09:40:56 +01:00
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt	doc: capitalization and other minor fixes in pnp doc	2010-02-05 12:22:44 +01:00
preempt-locking.txt
printk-formats.txt
prio_tree.txt
rbtree.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
SELinux.txt
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
slow-work.txt	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
SM501.txt
Smack.txt
sparse.txt
spinlocks.txt	Documentation: rw_lock lessons learned	2009-12-14 09:46:56 -08:00
stable_api_nonsense.txt
stable_kernel_rules.txt	Doc/stable rules: add new cherry-pick logic	2009-12-23 11:23:43 -08:00
SubmitChecklist	Documentation/SubmitChecklist: add rule #1	2010-03-12 15:52:35 -08:00
SubmittingDrivers
SubmittingPatches	docs: update patch size in SubmittingPatches	2009-10-01 16:11:12 -07:00
svga.txt
sysfs-rules.txt
sysrq.txt
tomoyo.txt
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt	vgaarbiter: fix a typo in the vgaarbiter Documentation	2009-12-16 11:28:58 -08:00
video-output.txt
volatile-considered-harmful.txt	Documentation/volatile-considered-harmful.txt: correct cpu_relax() documentation	2010-03-24 16:31:20 -07:00
zorro.txt