getpriority() and top display for priority is inconsistent
Lavrentiev, Anton (NIH/NLM/NCBI) [C] via cygwin
Tue Aug 6 18:54:00 GMT 2019
I have noticed a discrepancy between the process priority shown by "top" vs. what getpriority() returns.
I'm using the procps-based "top", so it reads the priority value from /proc/PID/stat. The value gets there via code found in "fhandler_process.cc":
/* The BasePriority returned to a 32 bit process under WOW64 is
apparently broken, for 32 and 64 bit target processes. 64 bit
processes get the correct base priority, even for 32 bit processes. */
if (wincap.is_wow64 ())
priority = 8; /* Default value. */
priority = pbi.BasePriority;
But that's an inconsistent way of generating the value, because it is supposed to be the one that "getpriority()" returns.
Also, it looks like the higher value in "pbi.BasePriority" corresponds to a higher process priority, while Unix priority is higher when the value is less
(20 - nice, generally).
It looks like it should have been done by calling a utility function, winprio_to_nice(GetPriorityClass(CurrentProcess())), and setting up both the priority
field (as "NZERO + winprio_to_nice()") and the following "nice" field (which is currently set to permanent zero) with what winprio_to_nice() returns.
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