RFR: 8150134: Simplify concurrent refinement thread deactivation
jon.masamitsu at oracle.com
Fri Feb 19 18:03:54 UTC 2016
On 2/18/2016 5:19 PM, Kim Barrett wrote:
>> On Feb 18, 2016, at 5:56 PM, Jon Masamitsu <jon.masamitsu at oracle.com> wrote:
>> Change looks good.
>> Is it correct that the deactivation threshold could be overshot
>> in the current implementation because the green zone can be less
>> than the deactivation threshold? I don't have any reason to think
>> that will cause a problem.
> The green zone should be less than the deactivation threshold for
> all but the primary thread (though there’s a separate bug already
> in JIRA where the thresholds are computed wrongly in some configs).
> The old code might have refinement threads sometimes do more
> work than their thresholds would suggest. OTOH, there are some
> rare situations where this change could result in an extra thread
> switch that wouldn’t have happened with the old code. But I think
> this change should be performance neutral, and is mostly intended
> to simplify things in preparation for further changes.
>> I know that the logging messages are as in the original but
>> I'd find
>> Deactivated %d, at threshold:
>> better than
>> Deactivated %d, off threshold:
>> at line 154 in the new version.
> Activation uses “on threshold” and deactivation uses “off threshold”,
> as in “turn on” / “turn off”. If “at threshold” were to be used, I think it
> should be applied to both. I think I’d rather keep those pieces distinct,
> for ease of grepping and the like.
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