Merge pull request #57 from angelabriel/master

change THP from 'never' to 'madvise' (bsc#1232373)

lib/sc_hooks.sh

@@ -33,15 +33,31 @@ lc_add() {
     sed -i 's/^# Set to 65536/# Set to 1048576 (as recommended by revision 6 of the SAP Note)/' "$SN"
 }
 
+thp_change() {
+    osvers=$(grep ^VERSION= /etc/os-release | awk -F \" '{ print $2 }')
+    case "$osvers" in
+    15-SP[567])
+        sed -i 's/^THP=never/THP=madvise/g' "$SN"
+        sed -i "s/^# set to 'never'/# set to 'madvise'/g" "$SN"
+        sed -i '/^# Disable transparent hugepages/i\
+# '\''madvise'\'' will enter direct reclaim like '\''always'\'' but only for regions that\
+# are have used madvise(MADV_HUGEPAGE). This is the default behaviour.' "$SN"
+        sed -i 's/^# Disable transparent hugepages/# Configure transparent hugepages/' "$SN"
+        ;;
+    esac
+}
+
 case "$hook_opt" in
 add)
     add_ignore
     lc_add
+    thp_change
     ;;
 del)
     del_ignore
     ;;
 nothing)
     lc_add
+    thp_change
     ;;
 esac

man/sapconf.5

@@ -14,7 +14,7 @@
 .\" * GNU General Public License for more details.
 .\" */
 .\" 
-.TH sapconf 5 "April 2023" "sapconf configuration file"
+.TH sapconf 5 "November 2024" "sapconf configuration file"
 .SH NAME
 sapconf \- central configuration file of sapconf
 
@@ -188,10 +188,13 @@ SAP Note 2684254
 .RE
 .PP
 .TP 4
-.BI THP=never
-Disable transparent hugepages.
+.BI THP=madvise
+Configure transparent hugepages.
 .br
-Set to 'never' to disable or to 'always' to enable.
+Set to 'never' to disable or to 'always' to enable or 'madvise'.
+.br
+\fBmadvise\fP will enter direct reclaim like 'always' but only for regions that
+are have used madvise(MADV_HUGEPAGE). This is the default behaviour.
 .PP
 .RS 4
 Set in \fB/sys/kernel/mm/transparent_hugepage/enabled\fP during the SAP tuning part of the scripting

sysconfig/sapconf

@@ -183,12 +183,14 @@ NUMA_BALANCING=0
 # /sys/kernel/mm/transparent_hugepage/enabled
 #
 # 'never' to disable, 'always' to enable
-# Disable transparent hugepages
-# set to 'never'
+# 'madvise' will enter direct reclaim like 'always' but only for regions that
+# are have used madvise(MADV_HUGEPAGE). This is the default behaviour.
+# Configure transparent hugepages
+# set to 'madvise'
 #
 # SAP Note 2131662, 2684254, 2031375
 #
-THP=never
+THP=madvise
 
 # Energy Performance Bias EPB (applies to Intel-based systems only)
 #