[Info-vax] High resolution per-process CPU consumption statistics

[VAXman- at SendSpamHere.ORG]

In article <m5reG.280253$YY1.29280 at fx08.iad>, Mark Daniel <mark.daniel at wasd.vsm.com.au> writes:
>On 24/3/20 9:24 pm, johnwallace4 at yahoo.co.uk wrote:
>> On Tuesday, 24 March 2020 00:02:22 UTC, Mark Daniel  wrote:
>>> Would like to be able to measure process CPU consumed during specified
>>> continuous sections of processing.  Only interested in CPU-intensive
>>> sections so USER mode consumed relevant.  Imagine inserting calls at the
>>> beginning and ending of those sections with a magic number representing
>>> CPU consumption/delta/whatever made available.
>>>
>>> As some of these CPU-intensive code sections are short duration the
>>> granularity needs to be quite fine.  The likes of JPI$_CPUTIM and
>>> LIB$STAT_TIMER (10mS) seem unsuitable.
>>>
>>> Prepared for non- USER mode code.  This is only for ad hoc developmental
>>> insight and not general use.  Needs to accommodate Alpha and/or Itanium
>>> (and/or x86-64 :-)
>>>
>>> And, of course, any other suggestion.
>>>
>>> As always, TIA.
>> 
>> Is it safe to assume that the code in question is single-threaded?
>
>Yes.
>
>> Is it safe to assume that the code in question is running on a
>> single-processor system?
>
>Yes.
>
>> Is an Alpha-only solution better than nothing at all?
>
>Sure.
>
>> Have a look at RPCC (Read Process Cycle Counter) in the Alpha/VMS
>> PALcode and see if it might help.
>> 
>> See e.g. the Alpha Architecture Reference Manual documentation e.g.
>> http://www.bitsavers.org/pdf/dec/alpha/Sites_AlphaArchitectureReferenceManual_1992.pdf
>> (there's probably more useful RPCC-related stuff available too).
>
>Before posting here, a fair effort with an unnamed but common search 
>engine and my chosen query strings consistently returned references to 
>that document and section.
>
>My fevered imagination (but internals hacking very-much limited to 
>monkey-see-monkey-do) has something of the ilk:
>
>    unsigned __int64  start_count,
>                      end_count;
>
>    void get_cpu_count (unsigned __int64 *here)
>    {
>       *here = EXE$GL_CURRENT_CPU_COUNT;
>       return SS$_NORMAL;
>    }
>
>    sys$cmkrnl (&get_cpu_count, &start_count);
>    ...
>    sys$cmkrnl (&get_cpu_count, &end_count);
>
>Some similar code would be used to obtain the RPCC.

SYS$RPCC_64.  No need to add jackets and or jump into inner mode.

No arguments.  It returns the RPCC value in R0, the function return.

-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

I speak to machines with the voice of humanity.