[PATCH] kdump/lib: introduce a script to return recommened mem size

[Pingfan Liu]

There is requirement to decide the recommended memory size for the current
system.

Implementing a script to achieve it.

Signed-off-by: Pingfan Liu <piliu(a)redhat.com&gt;
---
 kdump-lib-memsz.sh | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 kexec-tools.spec   |  2 ++
 2 files changed, 68 insertions(+)
 create mode 100644 kdump-lib-memsz.sh

diff --git a/kdump-lib-memsz.sh b/kdump-lib-memsz.sh
new file mode 100644
index 0000000..d524a9f
--- /dev/null
+++ b/kdump-lib-memsz.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+# kdump-api-memsz.sh
+# return recommended size based on current system RAM size
+
+#get system memory size in the unit of GB
+get_system_size()
+{
+	result=$( cat /proc/iomem  | grep "System RAM" | awk -F ":" {'
print $1 '} | tr [:lower:] [:upper:] | paste -sd+ )
+	result="+$result"
+	# replace '-' with '+0x' and '+' with '-0x'
+	sum=$( echo $result | sed -e 's/-/K0x/g' | sed -e 's/+/-0x/g' | sed -e
's/K/+/g' )
+	size=$(printf "%d\n" $(($sum)))
+	let size=$size/1024/1024/1024
+
+	echo $size
+}
+
+get_recommend_size()
+{
+	local mem_size=$1
+	local _ck_cmdline=$2
+
+	last_sz=""
+	last_unit=""
+
+	IFS=','
+	for i in $_ck_cmdline
+	do
+		end=$( echo $i | awk -F "-" {' print $2 '} | awk -F ":"
{' print $1 '} )
+		recommend=$( echo $i | awk -F "-" {' print $2 '} | awk -F
":" {' print $2 '} )
+		size=${end: : -1}
+		unit=${end: -1}
+		if [ $unit == 'T' ]; then
+			let size=$size*1024
+		fi
+		if [ $mem_size -lt $size ]; then
+			echo $recommend
+			return
+		fi
+	done
+	unset IFS
+}
+
+. /lib/kdump/kdump-lib.sh
+
+arch=$( lscpu | grep Architecture | awk -F ":" {' print $2 '} | tr
[:lower:] [:upper:] )
+
+if [ $arch == "X86_64" ] || [ $arch == "S390" ]; then
+        ck_cmdline="1G-4G:160M,4G-64G:192M,64G-1T:256M,1T-:512M"
+elif [ $arch == "ARM64" ]; then
+        ck_cmdline="2G-:448M"
+elif [ $arch == "PPC64LE" ]; then
+        if is_fadump_capable; then
+               
ck_cmdline="4G-16G:768M,16G-64G:1G,64G-128G:2G,128G-1T:4G,1T-2T:6G,2T-4T:12G,4T-8T:20G,8T-16T:36G,16T-32T:64G,32T-64T:128G,64T-:180G"
+        else
+               
ck_cmdline="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G"
+        fi
+fi
+
+ck_cmdline=$( echo $ck_cmdline | sed -e 's/-:/-102400T:/g' )
+
+sys_mem=$(get_system_size)
+
+result=$( get_recommend_size $sys_mem "$ck_cmdline" )
+
+echo $result
diff --git a/kexec-tools.spec b/kexec-tools.spec
index 623274c..7f982c6 100644
--- a/kexec-tools.spec
+++ b/kexec-tools.spec
@@ -38,6 +38,7 @@ Source28: kdump-udev-throttler
 Source29: kdump.sysconfig.aarch64
 Source30: 60-kdump.install
 Source31: kdump-logger.sh
+Source32: kdump-lib-memsz.sh
 
 #######################################
 # These are sources for mkdumpramfs
@@ -192,6 +193,7 @@ install -m 644 %{SOURCE25} $RPM_BUILD_ROOT%{_mandir}/man8/kdumpctl.8
 install -m 755 %{SOURCE20} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-lib.sh
 install -m 755 %{SOURCE23} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-lib-initramfs.sh
 install -m 755 %{SOURCE31} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-logger.sh
+install -m 755 %{SOURCE32} $RPM_BUILD_ROOT%{_prefix}/lib/kdump/kdump-lib-memsz.sh
 %ifnarch s390x
 install -m 755 %{SOURCE28} $RPM_BUILD_ROOT%{_udevrulesdir}/../kdump-udev-throttler
 %endif
-- 
2.7.5