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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>
1 parent 3eaa73b
Raw File
headers.sh 
#!/bin/sh
# Run headers_$1 command for all suitable architectures

# Stop on error
set -e

do_command()
{
	if [ -f ${srctree}/arch/$2/include/asm/Kbuild ]; then
		make ARCH=$2 KBUILD_HEADERS=$1 headers_$1
	else
		printf "Ignoring arch: %s\n" ${arch}
	fi
}

archs=${HDR_ARCH_LIST:-$(ls ${srctree}/arch)}

for arch in ${archs}; do
	case ${arch} in
	um)        # no userspace export
		;;
	cris)      # headers export are known broken
		;;
	*)
		if [ -d ${srctree}/arch/${arch} ]; then
			do_command $1 ${arch}
		fi
		;;
	esac
done
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