powerpc64 head -r344018 stuck sleeping problems: th->th_scale * tc_delta(th) overflows unsigned 64 bits sometimes [patched failed]

[Poul-Henning Kamp]

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In message <210dfd0f50ee6b1149c914ee503502654eb5f328.camel at freebsd.org>, Ian Lepore writes:
>On Fri, 2019-03-01 at 20:57 +0000, Poul-Henning Kamp wrote:
>> --------
>> In message <679402FF-907C-43AF-B18C-8C9CC857D7A6 at yahoo.com>, Mark
>> Millard via freebsd-hackers writes:
>> 
>> > > I must admit that 2 seconds of interval where the timehands where
>> > > not updated is too much.
>> 
>> I have no idea how you got in that situation, but it is very far
>> from how timecounters were designed to work.
>> 
>
>I wonder if it's fallout from reducing the number of timehands to 2,

Unless somebody added refcounting, that sounds even less safe.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.