RFR: 8307766: Linux: Provide the option to override the timer slack [v7]

[Thomas Stuefe]

On Sun, 2 Jul 2023 23:29:57 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> src/hotspot/os/linux/globals_linux.hpp line 90:
>> 
>>> 88:           "same as disabled override. See prctl(PR_SET_TIMERSLACK) for "\
>>> 89:           "more info.")                                                 \
>>> 90:                                                                         \
>> 
>> None of the other Linux specifc args write "(Linux specific)". I'd leave that out.
>> 
>> The first sentence is difficult to parse. How about "Overrides timer slack value to the given number of nanoseconds [1..n]."
>> 
>> Why do we need two values (-1, 0) for oob? Is the "In current Linux, 0..." info useful for anything? I'd just use "0" as "default".
>
> IIUC using zero as default would be incorrect as that may reset an inherited customized value to the platform default. A value of -1 says "ignore this".

We only call pctrl if the flag is >0. So, 0 has already the meaning of "ignore".

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PR Review Comment: https://git.openjdk.org/jdk/pull/13889#discussion_r1250433377