linux_dsm_epyc7002/arch
Anton Vorontsov 73863ab028 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>
2012-05-31 17:49:29 -07:00
..
alpha Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
arm arm: use clear_tasks_mm_cpumask() 2012-05-31 17:49:29 -07:00
avr32 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
blackfin Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
c6x Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
cris cris: select GENERIC_ATOMIC64 2012-05-29 16:22:18 -07:00
frv Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
h8300 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
hexagon Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
ia64 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
m32r Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-24 13:29:46 -07:00
m68k Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
microblaze Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze 2012-05-28 09:49:56 -07:00
mips Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2012-05-28 10:32:28 -07:00
mn10300 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
openrisc openrisc: use generic strnlen_user() function 2012-05-27 21:00:32 -07:00
parisc Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
powerpc powerpc: use clear_tasks_mm_cpumask() 2012-05-31 17:49:29 -07:00
s390 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
score Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
sh Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
sparc sparc: use the new generic strnlen_user() function 2012-05-26 11:33:54 -07:00
tile Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2012-05-25 15:59:38 -07:00
um um/kernel/trap.c: port OOM changes to handle_page_fault() 2012-05-31 17:49:26 -07:00
unicore32 Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
x86 mm: pmd_read_atomic: fix 32bit PAE pmd walk vs pmd_populate SMP race condition 2012-05-29 16:22:24 -07:00
xtensa Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2012-05-24 16:17:30 -07:00
.gitignore
Kconfig Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping 2012-05-25 09:18:59 -07:00