From 710b4a70321148b470bf55c73d81170f07c839f9 Mon Sep 17 00:00:00 2001 From: Aymeric Augustin Date: Thu, 10 Sep 2015 14:06:06 +0200 Subject: [PATCH] Avoided running more test processes than necessary. This reduces the time spent cloning databases. Thanks Tim for the suggestion. --- django/test/runner.py | 12 +++++++++++- docs/ref/django-admin.txt | 4 ++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/django/test/runner.py b/django/test/runner.py index 04ee14ec72..243ab714a4 100644 --- a/django/test/runner.py +++ b/django/test/runner.py @@ -453,7 +453,17 @@ class DiscoverRunner(object): suite = reorder_suite(suite, self.reorder_by, self.reverse) if self.parallel > 1: - suite = self.parallel_test_suite(suite, self.parallel, self.failfast) + parallel_suite = self.parallel_test_suite(suite, self.parallel, self.failfast) + + # Since tests are distributed across processes on a per-TestCase + # basis, there's no need for more processes than TestCases. + parallel_units = len(parallel_suite.subsuites) + if self.parallel > parallel_units: + self.parallel = parallel_units + + # If there's only one TestCase, parallelization isn't needed. + if self.parallel > 1: + suite = parallel_suite return suite diff --git a/docs/ref/django-admin.txt b/docs/ref/django-admin.txt index 4a7b03de43..dff48ac460 100644 --- a/docs/ref/django-admin.txt +++ b/docs/ref/django-admin.txt @@ -1274,6 +1274,10 @@ By default ``--parallel`` runs one process per core according to either by providing it as the option's value, e.g. ``--parallel=4``, or by setting the ``DJANGO_TEST_PROCESSES`` environment variable. +Django distributes test cases — :class:`unittest.TestCase` subclasses — to +subprocesses. If there are fewer test cases than configured processes, Django +will reduce the number of processes accordingly. + Each process gets its own database. You must ensure that different test cases don't access the same resources. For instance, test cases that touch the filesystem should create a temporary directory for their own use.