2013/5/20 Srivatsa S. Bhat <[email protected]>: > On 05/17/2013 02:14 PM, Li Zhong wrote: >> 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(), > > This above line is not relevant here, because notifier_call_chain() > doesn't use notifier_to/from_errno(). It simply uses a straight-forward > check like this: > > if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK) > break; > >> 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 <[email protected]> >> --- > > Reviewed-by: Srivatsa S. Bhat <[email protected]>
I applied the patch and will send to Ingo, thanks guys! > >> 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; >> > > Regards, > Srivatsa S. Bhat > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
