From b8b9170f9df44fab6480ed0a561c778d306ed657 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Wed, 23 Dec 2020 16:07:14 -0500
Subject: [PATCH] Remove Unix::Processors dependency

---
 ci/ci-install.bash            |  4 ++--
 ci/docker/buildenv/Dockerfile |  2 +-
 docs/install.adoc             |  1 -
 docs/internals.adoc           |  2 +-
 test_regress/driver.pl        | 15 ++++++++++-----
 5 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/ci/ci-install.bash b/ci/ci-install.bash
index 66216d5ff..7e0e4a398 100755
--- a/ci/ci-install.bash
+++ b/ci/ci-install.bash
@@ -55,7 +55,7 @@ if [ "$CI_BUILD_STAGE_NAME" = "build" ]; then
       sudo apt-get install libsystemc libsystemc-dev
     fi
     if [ "$COVERAGE" = 1 ]; then
-      yes yes | sudo cpan -fi Unix::Processors Parallel::Forker
+      yes yes | sudo cpan -fi Parallel::Forker
     fi
     if [ "$M32" = 1 ]; then
       sudo apt-get install gcc-multilib g++-multilib
@@ -100,7 +100,7 @@ elif [ "$CI_BUILD_STAGE_NAME" = "test" ]; then
   if [ "$CI_RUNS_ON" != "ubuntu-14.04" ]; then
     CI_CPAN_REPO=https://cpan.org
   fi
-  yes yes | sudo cpan -M $CI_CPAN_REPO -fi Unix::Processors Parallel::Forker
+  yes yes | sudo cpan -M $CI_CPAN_REPO -fi Parallel::Forker
   install-vcddiff
 
   autoconf
diff --git a/ci/docker/buildenv/Dockerfile b/ci/docker/buildenv/Dockerfile
index 6f9dd3539..7e6682357 100644
--- a/ci/docker/buildenv/Dockerfile
+++ b/ci/docker/buildenv/Dockerfile
@@ -40,7 +40,7 @@ RUN apt-get update \
 
 WORKDIR /tmp
 
-RUN cpan install -fi Unix::Processors Parallel::Forker
+RUN cpan install -fi Parallel::Forker
 
 RUN git clone https://github.com/veripool/vcddiff.git && \
     make -C vcddiff && \
diff --git a/docs/install.adoc b/docs/install.adoc
index 65ae632f3..ef88b1dce 100644
--- a/docs/install.adoc
+++ b/docs/install.adoc
@@ -100,7 +100,6 @@ Those developing Verilator itself may also want these (see internals.adoc):
 
    sudo apt-get install gdb asciidoctor graphviz cmake clang clang-format gprof lcov
    cpan install Pod::Perldoc
-   cpan install Unix::Processors
    cpan install Parallel::Forker
 
 ==== Install SystemC
diff --git a/docs/internals.adoc b/docs/internals.adoc
index c8eb93f70..11df4107a 100644
--- a/docs/internals.adoc
+++ b/docs/internals.adoc
@@ -697,7 +697,7 @@ Verilator problem.
 When enabling the long tests, some additional PERL modules are needed,
 which you can install using cpan.
 
-   cpan install Unix::Processors
+   cpan install Parallel::Forker
 
 There are some traps to avoid when running regression tests
 
diff --git a/test_regress/driver.pl b/test_regress/driver.pl
index f4214443f..61360b7e3 100755
--- a/test_regress/driver.pl
+++ b/test_regress/driver.pl
@@ -249,12 +249,17 @@ sub parameter {
     }
 }
 
+our $_Max_Procs;
 sub max_procs {
-    my $ok = eval "
-        use Unix::Processors;
-        return Unix::Processors->new->max_online;
-    ";
-    return $ok;
+    if (!defined $_Max_Procs) {
+        $_Max_Procs = `python3 -c 'import multiprocessing\nprint(multiprocessing.cpu_count())'`;
+        chomp $_Max_Procs;
+        if ($_Max_Procs < 2) {
+            $_Max_Procs = 2;
+            warn "driver.pl: Python didn't find at least two CPUs\n";
+        }
+    }
+    return $_Max_Procs;
 }
 
 sub calc_threads {