aha/include
Max Krasnyansky e761b77252 cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2)
This is based on Linus' idea of creating cpu_active_map that prevents
scheduler load balancer from migrating tasks to the cpu that is going
down.

It allows us to simplify domain management code and avoid unecessary
domain rebuilds during cpu hotplug event handling.

Please ignore the cpusets part for now. It needs some more work in order
to avoid crazy lock nesting. Although I did simplfy and unify domain
reinitialization logic. We now simply call partition_sched_domains() in
all the cases. This means that we're using exact same code paths as in
cpusets case and hence the test below cover cpusets too.
Cpuset changes to make rebuild_sched_domains() callable from various
contexts are in the separate patch (right next after this one).

This not only boots but also easily handles
	while true; do make clean; make -j 8; done
and
	while true; do on-off-cpu 1; done
at the same time.
(on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing).

Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing
this on right now in gnome-terminal and things are moving just fine.

Also this is running with most of the debug features enabled (lockdep,
mutex, etc) no BUG_ONs or lockdep complaints so far.

I believe I addressed all of the Dmitry's comments for original Linus'
version. I changed both fair and rt balancer to mask out non-active cpus.
And replaced cpu_is_offline() with !cpu_active() in the main scheduler
code where it made sense (to me).

Signed-off-by: Max Krasnyanskiy <maxk@qualcomm.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Gregory Haskins <ghaskins@novell.com>
Cc: dmitry.adamushko@gmail.com
Cc: pj@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-18 13:22:25 +02:00
..
acpi Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
asm-alpha
asm-arm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2008-07-16 15:17:52 -07:00
asm-avr32 atmel-mci: Driver for Atmel on-chip MMC controllers 2008-07-15 14:14:49 +02:00
asm-blackfin
asm-cris
asm-frv frv: fix irqs_disabled() to return an int, not an unsigned long 2008-07-12 14:33:42 -07:00
asm-generic Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2008-07-16 17:25:46 -07:00
asm-h8300
asm-ia64 ACPI : Create "idle=nomwait" bootparam 2008-07-16 23:27:05 +02:00
asm-m32r
asm-m68k
asm-m68knommu
asm-mips Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc 2008-07-16 15:17:52 -07:00
asm-mn10300
asm-parisc
asm-powerpc Merge commit 'origin/master' 2008-07-16 11:07:59 +10:00
asm-s390 [S390] qdio: new qdio driver. 2008-07-17 17:22:10 +02:00
asm-sh
asm-sparc
asm-sparc64
asm-um
asm-v850
asm-x86 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-17 10:38:59 -07:00
asm-xtensa
crypto
drm drm/radeon: fixup issue with radeon and PAT support. 2008-07-15 15:48:05 +10:00
keys
linux cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) 2008-07-18 13:22:25 +02:00
math-emu
media
mtd
net
pcmcia
rdma RDMA/addr: Keep pointer to netdevice in struct rdma_dev_addr 2008-07-14 23:48:53 -07:00
rxrpc
scsi Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2008-07-15 18:58:04 -07:00
sound ALSA: Release v1.0.17 2008-07-14 09:54:43 +02:00
video
xen
Kbuild drm: reorganise drm tree to be more future proof. 2008-07-14 10:45:01 +10:00