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Revision 73863ab028579ed98c4f1f36d016536b1b415344 authored by Anton Vorontsov on 31 May 2012, 23:26:23 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:29 UTC 
powerpc: use clear_tasks_mm_cpumask()
 
Current CPU hotplug code has some task->mm handling issues:

1. Working with task->mm w/o getting mm or grabing the task lock is
   dangerous as ->mm might disappear (exit_mm() assigns NULL under
   task_lock(), so tasklist lock is not enough).

   We can't use get_task_mm()/mmput() pair as mmput() might sleep,
   so we must take the task lock while handle its mm.

2. Checking for process->mm is not enough because process' main
   thread may exit or detach its mm via use_mm(), but other threads
   may still have a valid mm.

   To fix this we would need to use find_lock_task_mm(), which would
   walk up all threads and returns an appropriate task (with task
   lock held).

clear_tasks_mm_cpumask() has all the issues fixed, so let's use it.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Makefile 
#
# arch/arm/boot/Makefile
#
# This file is subject to the terms and conditions of the GNU General Public
# License.  See the file "COPYING" in the main directory of this archive
# for more details.
#
# Copyright (C) 1995-2000 Russell King
#

targets := Image zImage bootpImage

SYSTEM	=$(LINUX)

ZTEXTADDR	 = 0x02080000
PARAMS_PHYS	 = 0x0207c000
INITRD_PHYS	 = 0x02180000
INITRD_VIRT	 = 0x02180000

#
# If you don't define ZRELADDR above,
# then it defaults to ZTEXTADDR
#
ifeq ($(ZRELADDR),)
ZRELADDR	= $(ZTEXTADDR)
endif

export	SYSTEM ZTEXTADDR ZBSSADDR ZRELADDR INITRD_PHYS INITRD_VIRT PARAMS_PHYS

Image: $(obj)/Image

targets: $(obj)/Image

$(obj)/Image: vmlinux FORCE
	$(OBJCOPY) -O binary -R .note -R .comment -S vmlinux $@

#$(obj)/Image:	$(CONFIGURE) $(SYSTEM)
#	$(OBJCOPY) -O binary -R .note -R .comment -g -S $(SYSTEM) $@

bzImage: zImage

zImage:	$(CONFIGURE) compressed/$(LINUX)
	$(OBJCOPY) -O binary -R .note -R .comment -S compressed/$(LINUX) $@

bootpImage: bootp/bootp
	$(OBJCOPY) -O binary -R .note -R .comment -S bootp/bootp $@

compressed/$(LINUX): $(LINUX) dep
	@$(MAKE) -C compressed $(LINUX)

bootp/bootp: zImage initrd
	@$(MAKE) -C bootp bootp

initrd:
	@test "$(INITRD_VIRT)" != "" || (echo This architecture does not support INITRD; exit -1)
	@test "$(INITRD)" != "" || (echo You must specify INITRD; exit -1)

#
# installation
#
install: $(CONFIGURE) Image
	sh ./install.sh $(KERNELRELEASE) Image System.map "$(INSTALL_PATH)"

zinstall: $(CONFIGURE) zImage
	sh ./install.sh $(KERNELRELEASE) zImage System.map "$(INSTALL_PATH)"

#
# miscellany
#
mrproper clean:
#	@$(MAKE) -C compressed clean
#	@$(MAKE) -C bootp clean

dep:
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