Merge: selftests/mm: fix va_high_addr_switch.sh failure

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/7653

JIRA: https://issues.redhat.com/browse/RHEL-130531

The series is for fixing kselftest hugevm va_high_addr_switch test failure caused by two issues, one issue is no enough hugepage caused failure, the other issues is the unaligned hint addr caused test failure.

Added several more commits to resolve the dependency or reduce the conflict context. As the run_vmtests.sh is the entrypoint of all sub tests and some setups are done there,and because of the far distance between the 5.14 and 6.17, there're conflicts on the file in two of the commits.

And patch one is a RHEL-only fix, could help to reduce some conflict on vm_runtests.sh.

We don't have guard pages feature as no 662df3e ("mm: madvise: implement lightweight guard page mechanism") in rhel9, which is added in v6.13-rc1, and in this version the the guard-pages.c/guard-regions.c test are added. So ignored the commit 6d21130 ("selftests/mm: skip guard_regions.uffd tests when uffd is not present") in the dependency series.

Commit cc92882 ("mm: drop hugetlb_get_unmapped_area{_*} functions") is not in the rhel9, in which commit the hint addr round way changed and breaks the test. Commit c563252 ("selftests/mm: fix va_high_addr_switch.sh failure on x86_64") is originally for fixing the broken, using hugepage aligned hint address independent of the align (round up or down) direction being used in the kernel, making it portable, so add it together with the series.

Signed-off-by: Chunyu Hu <chuhu@redhat.com>

Approved-by: Rafael Aquini <raquini@redhat.com>
Approved-by: Luiz Capitulino <luizcap@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Patrick Talbert <ptalbert@redhat.com>

Author: ptalbert

tools/testing/selftests/mm/run_vmtests.sh

@@ -160,13 +160,13 @@ fi
 
 # set proper nr_hugepages
 if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
-	nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
+	orig_nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
 	needpgs=$((needmem_KB / hpgsize_KB))
 	tries=2
 	while [ "$tries" -gt 0 ] && [ "$freepgs" -lt "$needpgs" ]; do
 		lackpgs=$((needpgs - freepgs))
 		echo 3 > /proc/sys/vm/drop_caches
-		if ! echo $((lackpgs + nr_hugepgs)) > /proc/sys/vm/nr_hugepages; then
+		if ! echo $((lackpgs + orig_nr_hugepgs)) > /proc/sys/vm/nr_hugepages; then
 			echo "Please run this test as root"
 			exit $ksft_skip
 		fi
@@ -177,13 +177,15 @@ if [ -n "$freepgs" ] && [ -n "$hpgsize_KB" ]; then
 		done < /proc/meminfo
 		tries=$((tries - 1))
 	done
+	nr_hugepgs=$(cat /proc/sys/vm/nr_hugepages)
 	if [ "$freepgs" -lt "$needpgs" ]; then
 		printf "Not enough huge pages available (%d < %d)\n" \
 		       "$freepgs" "$needpgs"
 	fi
+	HAVE_HUGEPAGES=1
 else
 	echo "no hugetlbfs support in kernel?"
-	exit 1
+	HAVE_HUGEPAGES=0
 fi
 
 # filter 64bit architectures
@@ -212,23 +214,33 @@ pretty_name() {
 # Usage: run_test [test binary] [arbitrary test arguments...]
 run_test() {
 	if test_selected ${CATEGORY}; then
-		echo "running: $1"
+		local skip=0
+
 		# On memory constrainted systems some tests can fail to allocate hugepages.
 		# perform some cleanup before the test for a higher success rate.
-		if [ ${CATEGORY} == "thp" ] | [ ${CATEGORY} == "hugetlb" ]; then
-			echo 3 > /proc/sys/vm/drop_caches
-			sleep 2
-			echo 1 > /proc/sys/vm/compact_memory
-			sleep 2
+		if [ ${CATEGORY} == "thp" -o ${CATEGORY} == "hugetlb" ]; then
+			if [ "${HAVE_HUGEPAGES}" = "1" ]; then
+				echo 3 > /proc/sys/vm/drop_caches
+				sleep 2
+				echo 1 > /proc/sys/vm/compact_memory
+				sleep 2
+			else
+				echo "hugepages not supported" | tap_prefix
+				skip=1
+			fi
 		fi
 
 		local test=$(pretty_name "$*")
 		local title="running $*"
 		local sep=$(echo -n "$title" | tr "[:graph:][:space:]" -)
 		printf "%s\n%s\n%s\n" "$sep" "$title" "$sep" | tap_prefix
 
-		("$@" 2>&1) | tap_prefix
-		local ret=${PIPESTATUS[0]}
+		if [ "${skip}" != "1" ]; then
+			("$@" 2>&1) | tap_prefix
+			local ret=${PIPESTATUS[0]}
+		else
+			local ret=$ksft_skip
+		fi
 		count_total=$(( count_total + 1 ))
 		if [ $ret -eq 0 ]; then
 			count_pass=$(( count_pass + 1 ))
@@ -265,13 +277,15 @@ CATEGORY="hugetlb" run_test ./hugepage-mremap
 CATEGORY="hugetlb" run_test ./hugepage-vmemmap
 CATEGORY="hugetlb" run_test ./hugetlb-madvise 
 
-nr_hugepages_tmp=$(cat /proc/sys/vm/nr_hugepages)
-# For this test, we need one and just one huge page
-echo 1 > /proc/sys/vm/nr_hugepages
-CATEGORY="hugetlb" run_test ./hugetlb_fault_after_madv
-CATEGORY="hugetlb" run_test ./hugetlb_madv_vs_map
-# Restore the previous number of huge pages, since further tests rely on it
-echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages
+if [ "${HAVE_HUGEPAGES}" = "1" ]; then
+	nr_hugepages_tmp=$(cat /proc/sys/vm/nr_hugepages)
+	# For this test, we need one and just one huge page
+	echo 1 > /proc/sys/vm/nr_hugepages
+	CATEGORY="hugetlb" run_test ./hugetlb_fault_after_madv
+	CATEGORY="hugetlb" run_test ./hugetlb_madv_vs_map
+	# Restore the previous number of huge pages, since further tests rely on it
+	echo "$nr_hugepages_tmp" > /proc/sys/vm/nr_hugepages
+fi
 
 if test_selected "hugetlb"; then
 	echo "NOTE: These hugetlb tests provide minimal coverage.  Use"	  | tap_prefix
@@ -371,7 +385,9 @@ CATEGORY="madv_populate" run_test ./madv_populate
 CATEGORY="memfd_secret" run_test ./memfd_secret
 
 # KSM KSM_MERGE_TIME_HUGE_PAGES test with size of 100
-CATEGORY="ksm" run_test ./ksm_tests -H -s 100
+if [ "${HAVE_HUGEPAGES}" = "1" ]; then
+	CATEGORY="ksm" run_test ./ksm_tests -H -s 100
+fi
 # KSM KSM_MERGE_TIME test with size of 100
 CATEGORY="ksm" run_test ./ksm_tests -P -s 100
 # KSM MADV_MERGEABLE test with 10 identical pages
@@ -420,6 +436,10 @@ CATEGORY="migration" run_test ./migration
 
 CATEGORY="mkdirty" run_test ./mkdirty
 
+if [ "${HAVE_HUGEPAGES}" = 1 ]; then
+	echo "$orig_nr_hugepgs" > /proc/sys/vm/nr_hugepages
+fi
+
 echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix
 echo "1..${count_total}" | tap_output