Messages in this thread | | | Date | Tue, 8 Sep 2015 12:40:08 +0200 | From | Peter Zijlstra <> | Subject | Re: Possible deadlock related to CPU hotplug and kernfs |
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On Mon, Sep 07, 2015 at 11:33:21PM +0200, Rafael J. Wysocki wrote: > On Monday, September 07, 2015 11:11:19 AM Jiang Liu wrote: > Peter, Ingo, some help from lockdep expert is needed. > > We have a splat that almost certainly is a false positive (the original report > is here http://marc.info/?l=linux-kernel&m=144109156901959&w=4) and no ideas > how to make it go away. Can you please have a look and advise?
I can't even find the relevant code :/
From that email I get kernfs_fop_write() which calls kernfs_get_active(), but that does _NOT_ call cpu_up(), so that callchain is shite.
The actual lockdep splat is also not really helpful, and is spraying names over: acpi, device, sysfs and kernfs (do we really need that many layeres of obfuscation for a simple file?)
So, please, start by explaining the thing proper such that simple people like me know what to look for.
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