RFR: 7194254 jstack reports wrong thread priorities

[David Holmes]

On 7/09/2012 6:21 PM, Dmytro Sheyko wrote:
> David,
>
> Maybe it makes sense to do some little corrections in format specifiers:
>
> st->print("#" INT64_FORMAT " ", java_lang_Thread::thread_id(thread_oop));
> if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
> st->print("prio=" INT32_FORMAT " ", java_lang_Thread::priority(thread_oop));
>
> instead of
>
> st->print("#%ld ", java_lang_Thread::thread_id(thread_oop));
> if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
> st->print("prio=%d ", java_lang_Thread::priority(thread_oop));

I confused myself over the correctness of %ld versus your original %llx 
- sorry.  The %d is fine and is used elsewhere when printing the priority.

Webrev updated at same location.

Thanks,
David

> Thanks,
> Dmytro
>
>
>  > Date: Fri, 7 Sep 2012 16:54:32 +1000
>  > From: david.holmes at oracle.com
>  > To: hotspot-dev at openjdk.java.net
>  > CC: dmytro_sheyko at hotmail.com; serviceability-dev at openjdk.java.net
>  > Subject: RFR: 7194254 jstack reports wrong thread priorities
>  >
>  > This is a formal request for review for the patch contributed by Dymtro
>  > Sheyko as discussed previously here:
>  >
>  >
> http://mail.openjdk.java.net/pipermail/hotspot-dev/2012-August/006376.html
>  >
>  > I am one reviewer of course.
>  >
>  > The webrev is here:
>  >
>  > http://cr.openjdk.java.net/~dholmes/7194254/webrev.v1/
>  >
>  > The fix has two components:
>  >
>  > 1. It fixes a bug in os::get_priority that assumed a more positive
>  > integer was always higher priority than a less positive one.
>  >
>  > 2. It addresses the problem that os::get_priority is often inexact when
>  > desiring the Java thread priority (because the mapping from Java
>  > priority to OS priority is often M:1) by not using it in
>  > Threads::print_on. Instead Threads::print_on will always report the
>  > native OS priority, and JavaThread::print_on() will print the
>  > java.lang.Thread.getId() value together with the
>  > java.lang.Thread.getPriority() value.
>  >
>  > This change in output affects all stackdumps including crash logs and
>  > thread dumps (including those shown by jstack).
>  >
>  > There is also a test program to check jstack output. I'll be doing some
>  > additional validation while the RFR is in progress.
>  >
>  > Thanks,
>  > David