testsuite lib/Benchmark unresponsive on older SPARC Solaris 10 server #16003
Created by firstname.lastname@example.org
Please ignore the version of perlbug used to submit this bug.
I performed a normal compile of Perl 5.26.0 from the release
Ran the testsuite and the process seemed fine until the Benchmark
CPU usage was seen to be at 98% for the entire duration.
Some details here are the environment variables in place during
mimas$ env | sort
I then tried to run the test in a more verbose manner :
$ LD_LIBRARY_PATH=/usr/local/build/perl-5.26.0_SunOS_5.10.001 ./perl harness -v ../lib/Benchmark.t
While this was running and seemingly wedged I ran truss also :
mimas # ps -ef | grep perl
Seemed to be in a loop doing not very much.
On the advice of some folks in the perl IRC chan p5p we ran a
$ /usr/local/bin/wget https://rt-archive.perl.org/perl5/Ticket/Attachment/1463473/794827/xBenchmark.t
2017-06-07 18:14:16 (3.16 MB/s) - 'xBenchmark.t' saved 
dclarke@mimas_$ file xBenchmark.t
dclarke@mimas_$ cd ../t
Again this seemed wedged and nonresponsive.
Here is some data from the built perl 5.26.0 :
Characteristics of this binary (from libperl):
Seems to be a single test failure on a machine which is older and slower
On Wed, 07 Jun 2017 19:57:52 GMT, email@example.com wrote:
More diagnostic suggestions. Two possible approaches:
1. via 'git'
If you have 'git' on the machine in question, do a checkout of the 'jkeenan/131531-benchmark' from our repository. (Call: 'perldoc perlhack' and 'perldoc perlgit' for more details.) Configure as you normally would. Call 'make' as you normally would. Then run (I'm guessing somewhat here):
LD_LIBRARY_PATH=`pwd` ./perl -Ilib lib/yBenchmark.t
'yBenchmark.t' is a very stripped-down version of lib/Benchmark.t.
2. via already-checked-out tarball
Store the version of 'lib/Benchmark.pm' in build directory someplace safe. Replace it with the 'Benchmark.pm' attached, to which I have added extra debugging statements. Place attached 'yBenchmark.t' in lib/. Call the same command as (1) above.
In either approach, assuming you get the inordinate slowness, you can try to use the Perl debugger to step through the test file, probably like this:
use Benchmark qw(:all);
my $foo = 0;
What was bug report RT #131531 is now GH issue Perl#16003.
We haven't heard from the original poster since June 2017. I am taking this ticket for the purpose of closing it (and corresponding p.r. #18777) at the end of this month unless we get a response.
Thank you very much.
Closing ticket as per schedule.