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kdump-lib: use non-debug kernels first 

Kdump uses currently running kernel as default, but when currently
running kernel is a debug kernel, it will consume more memory,
which may cause out-of-memory and fail to collect vmcore.

Now we will try to use non-debug kernels first if possible.

Also extract the logic of determine KDUMP_KERNEL from
prepare_kdump_bootinfo into a function. This function will return
KDUMP_KERNEL given a kernel version.

Signed-off-by: Lichen Liu <lichliu@redhat.com>
Acked-by: Coiby Xu <coxu@redhat.com>
This commit is contained in:
Lichen Liu 2022-06-13 12:08:08 +08:00 committed by Coiby Xu
parent 6f9653b918
commit c5bdd2d8f1
1 changed files with 51 additions and 20 deletions
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71
kdump-lib.sh
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@ -633,8 +633,36 @@ prepare_kexec_args()
echo "$kexec_args"
}
# prepare_kdump_kernel <kdump_kernelver>
# This function return kdump_kernel given a kernel version.
prepare_kdump_kernel()
{
local kdump_kernelver=$1
local dir img boot_dirlist boot_imglist kdump_kernel machine_id
read -r machine_id < /etc/machine-id
boot_dirlist=${KDUMP_BOOTDIR:-"/boot /boot/efi /efi /"}
boot_imglist="$KDUMP_IMG-$kdump_kernelver$KDUMP_IMG_EXT $machine_id/$kdump_kernelver/$KDUMP_IMG"
# Use BOOT_IMAGE as reference if possible, strip the GRUB root device prefix in (hd0,gpt1) format
boot_img="$(sed "s/^BOOT_IMAGE=\((\S*)\)\?\(\S*\) .*/\2/" /proc/cmdline)"
if [[ "$boot_img" == *"$kdump_kernelver" ]]; then
boot_imglist="$boot_img $boot_imglist"
fi
for dir in $boot_dirlist; do
for img in $boot_imglist; do
if [[ -f "$dir/$img" ]]; then
kdump_kernel=$(echo "$dir/$img" | tr -s '/')
break 2
fi
done
done
echo "$kdump_kernel"
}
#
# Detect initrd and kernel location, results are stored in global enviromental variables:
# Detect initrd and kernel location, results are stored in global environmental variables:
# KDUMP_BOOTDIR, KDUMP_KERNELVER, KDUMP_KERNEL, DEFAULT_INITRD, and KDUMP_INITRD
#
# Expectes KDUMP_BOOTDIR, KDUMP_IMG, KDUMP_IMG_EXT, KDUMP_KERNELVER to be loaded from config already
@ -642,37 +670,40 @@ prepare_kexec_args()
#
prepare_kdump_bootinfo()
{
local boot_img boot_imglist boot_dirlist boot_initrdlist
local machine_id dir img default_initrd_base var_target_initrd_dir
local boot_initrdlist nondebug_kernelver debug_kernelver
local default_initrd_base var_target_initrd_dir
if [[ -z $KDUMP_KERNELVER ]]; then
KDUMP_KERNELVER="$(uname -r)"
KDUMP_KERNELVER=$(uname -r)
nondebug_kernelver=$(sed -n -e 's/\(.*\)+debug$/\1/p' <<< "$KDUMP_KERNELVER")
fi
read -r machine_id < /etc/machine-id
boot_dirlist=${KDUMP_BOOTDIR:-"/boot /boot/efi /efi /"}
boot_imglist="$KDUMP_IMG-$KDUMP_KERNELVER$KDUMP_IMG_EXT $machine_id/$KDUMP_KERNELVER/$KDUMP_IMG"
# Use BOOT_IMAGE as reference if possible, strip the GRUB root device prefix in (hd0,gpt1) format
boot_img="$(sed "s/^BOOT_IMAGE=\((\S*)\)\?\(\S*\) .*/\2/" /proc/cmdline)"
if [[ -n $boot_img ]]; then
boot_imglist="$boot_img $boot_imglist"
# Use nondebug kernel if possible, because debug kernel will consume more memory and may oom.
if [[ -n $nondebug_kernelver ]]; then
dinfo "Trying to use $nondebug_kernelver."
debug_kernelver=$KDUMP_KERNELVER
KDUMP_KERNELVER=$nondebug_kernelver
fi
for dir in $boot_dirlist; do
for img in $boot_imglist; do
if [[ -f "$dir/$img" ]]; then
KDUMP_KERNEL=$(echo "$dir/$img" | tr -s '/')
break 2
fi
done
done
KDUMP_KERNEL=$(prepare_kdump_kernel "$KDUMP_KERNELVER")
if ! [[ -e $KDUMP_KERNEL ]]; then
if [[ -n $debug_kernelver ]]; then
dinfo "Fallback to using debug kernel"
KDUMP_KERNELVER=$debug_kernelver
KDUMP_KERNEL=$(prepare_kdump_kernel "$KDUMP_KERNELVER")
fi
fi
if ! [[ -e $KDUMP_KERNEL ]]; then
derror "Failed to detect kdump kernel location"
return 1
fi
if [[ "$KDUMP_KERNEL" == *"+debug" ]]; then
dwarn "Using debug kernel, you may need to set a larger crashkernel than the default value."
fi
# Set KDUMP_BOOTDIR to where kernel image is stored
KDUMP_BOOTDIR=$(dirname "$KDUMP_KERNEL")