Messages in this thread | | | Date | Thu, 03 Oct 2013 00:41:45 +0800 | From | Chen Gang F T <> | Subject | Re: [Suggestion] about calling debug_hotplug_cpu() which enabled by 'allmodconfig' for a x86_64 dual core laptop. |
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On 10/02/2013 11:28 PM, Toshi Kani wrote: > On Wed, 2013-10-02 at 03:10 +0000, Chen Gang wrote: >> Hello Maintainers: >> >> Under my x86_64 dual core laptop, I build kernel next-20130927 with >> 'allmodconfig', and install it, the machine can not start. Related >> information is: >> >> after call debug_hotplug_cpu(), output "cpu 0 is offline" .... and then "Failed to execute /init". >> >> After remove "_debug_hotplug_cpu(0, 0);", can pass the issue (but will >> fail in another place). I guess, the reason is my laptop cpu is not >> 'hotplug', but have to call debug_hotplug_cpu() with allmodconfig. >> >> >> I will continue analyzing, welcome any additional suggestions or >> completions. > > allmodconfig sets CONFIG_DEBUG_HOTPLUG_CPU0 to y (which is defined as > "def_bool n"), which puts CPU0 offline during boot for testing. This > debug feature is causing the problem on your laptop. I am not familiar > with allmodconfig, but it seems that it enables all the config options, > preferably with 'm'. >
Hmm... excuse me, I don't know: for laptop, if cpu0 is offline, whether it still can work or not. If any members know about it, please tell me, thanks.
In my opinion, if enable DEBUG_HOTPLUG_CPU0, but "should not let cpu0 offline for laptop", we need let 'offline' operation fail.
And I am analyzing (just constructing environments: KVM, kgdb ...), before let kernel start successfully, only according to my current proofs, we can not say "let laptop cpu0 offline" must be an issue.
Thanks.
> Thanks, > -Toshi > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
Thanks. -- Chen Gang
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