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From:   Joel Savitz <jsavitz@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     Joel Savitz <jsavitz@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Shuah Khan <shuah@kernel.org>,
        David Hildenbrand <dhildenb@redhat.com>,
        Nico Pache <npache@redhat.com>, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org
Subject: [PATCH linux-next] selftests/vm: calculate variables in correct order
Date:   Fri, 28 Oct 2022 09:26:40 -0400
Message-Id: <20221028132640.2791026-1-jsavitz@redhat.com>
MIME-Version: 1.0
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commit b5ba705c2608 ("selftests/vm: enable running select groups of tests")
unintentionally reversed the ordering of some of the lines of
run_vmtests.sh that calculate values based on system configuration.
Importantly, $hpgsize_MB is determined from $hpgsize_KB, but this later
value is not read from /proc/meminfo until later, causing userfaultfd
tests to incorrectly fail since $half_ufd_size_MB will always be 0.

Switch these statements around into proper order to fix the invocation
of the userfaultfd tests that use $half_ufd_size_MB.

Suggested-by: Nico Pache <npache@redhat.com>
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
---
 tools/testing/selftests/vm/run_vmtests.sh | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/vm/run_vmtests.sh b/tools/testing/selftests/vm/run_vmtests.sh
index fff00bb77086..ce52e4f5ff21 100755
--- a/tools/testing/selftests/vm/run_vmtests.sh
+++ b/tools/testing/selftests/vm/run_vmtests.sh
@@ -82,16 +82,6 @@ test_selected() {
 	fi
 }
 
-# Simple hugetlbfs tests have a hardcoded minimum requirement of
-# huge pages totaling 256MB (262144KB) in size.  The userfaultfd
-# hugetlb test requires a minimum of 2 * nr_cpus huge pages.  Take
-# both of these requirements into account and attempt to increase
-# number of huge pages available.
-nr_cpus=$(nproc)
-hpgsize_MB=$((hpgsize_KB / 1024))
-half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128))
-needmem_KB=$((half_ufd_size_MB * 2 * 1024))
-
 # get huge pagesize and freepages from /proc/meminfo
 while read -r name size unit; do
 	if [ "$name" = "HugePages_Free:" ]; then
@@ -102,6 +92,16 @@ while read -r name size unit; do
 	fi
 done < /proc/meminfo
 
+# Simple hugetlbfs tests have a hardcoded minimum requirement of
+# huge pages totaling 256MB (262144KB) in size.  The userfaultfd
+# hugetlb test requires a minimum of 2 * nr_cpus huge pages.  Take
+# both of these requirements into account and attempt to increase
+# number of huge pages available.
+nr_cpus=$(nproc)
+hpgsize_MB=$((hpgsize_KB / 1024))
+half_ufd_size_MB=$((((nr_cpus * hpgsize_MB + 127) / 128) * 128))
+needmem_KB=$((half_ufd_size_MB * 2 * 1024))
+
 # set proper nr_hugepages
 if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
 	nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
-- 
2.31.1