Commit-ID: 51a96c77815e7f139892a6e9c8275a50e9baebdf Gitweb: http://git.kernel.org/tip/51a96c77815e7f139892a6e9c8275a50e9baebdf Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> AuthorDate: Fri, 19 Nov 2010 20:37:53 +0100 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 23 Nov 2010 10:29:08 +0100 cpu: Remove incorrect BUG_ON Oleg mentioned that there is no actual guarantee the dying cpu's migration thread is actually finished running when we get there, so replace the BUG_ON() with a spinloop waiting for it. Reported-by: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/cpu.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index 3945066..cb7a1ef 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -249,8 +249,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) * The migration_call() CPU_DYING callback will have removed all * runnable tasks from the cpu, there's only the idle task left now * that the migration thread is done doing the stop_machine thing. + * + * Wait for the stop thread to go away. */ - BUG_ON(!idle_cpu(cpu)); + while (!idle_cpu(cpu)) + cpu_relax(); /* This actually kills the CPU. */ __cpu_die(cpu); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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