Messages in this thread Patch in this message | | | Subject | [RFC PATCH nohz] return NOTIFY_BAD in cpu down call back to stop offlining the cpu | From | Li Zhong <> | Date | Fri, 17 May 2013 16:44:04 +0800 |
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In tick_nohz_cpu_down_callback() if the cpu is the one handling timekeeping , it seems that we should return something that could stop notify CPU_DOWN_PREPARE, and then start notify CPU_DOWN_FAILED on the already called notifier call backs.
-EINVAL will be converted to 0 by notifier_to_errno(), then the cpu would be taken down with part of the DOWN_PREPARE notifier callbacks called, and something bad could happen after that.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> --- kernel/time/tick-sched.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index bc67d42..17b8155 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -306,7 +306,7 @@ static int __cpuinit tick_nohz_cpu_down_callback(struct notifier_block *nfb, * we can't safely shutdown that CPU. */ if (have_nohz_full_mask && tick_do_timer_cpu == cpu) - return -EINVAL; + return NOTIFY_BAD; break; } return NOTIFY_OK; -- 1.7.1
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