Re: [PATCH] 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. You can still specify the kernel by setting the KDUMP_KERNELVER in /etc/sysconfig/kdump. This patch may only works for Fedora and RHEL, since we rely on the "+debug" suffix to determine if the currently running kernel is a debug version. For other distros, fallback to using the currently running kernel.

Signed-off-by: Lichen Liu <lichliu(a)redhat.com&gt; --- kdump-lib.sh | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/kdump-lib.sh b/kdump-lib.sh index b137c89..bd4eeed 100755 --- a/kdump-lib.sh +++ b/kdump-lib.sh @@ -642,11 +642,21 @@ prepare_kexec_args() # prepare_kdump_bootinfo() { - local boot_img boot_imglist boot_dirlist boot_initrdlist + local boot_img boot_imglist boot_dirlist boot_initrdlist nondebug_kernelver debug_kernelver debug_imglist local machine_id dir img default_initrd_base var_target_initrd_dir if [[ -z $KDUMP_KERNELVER ]]; then KDUMP_KERNELVER="$(uname -r)" + nondebug_kernelver="$(echo -n "$KDUMP_KERNELVER" | sed -n -e 's/\(.*\)+debug$/\1/p')" + fi + + + # 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" + debug_imglist="$KDUMP_IMG-$debug_kernelver$KDUMP_IMG_EXT $machine_id/$debug_kernelver/$KDUMP_IMG" + KDUMP_KERNELVER="$nondebug_kernelver" fi read -r machine_id < /etc/machine-id @@ -656,7 +666,11 @@ prepare_kdump_bootinfo() # 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 $boot_imglist" + if [[ "$boot_img" == *"+debug"* ]]; then + debug_imglist="$boot_img $debug_imglist" + else + boot_imglist="$boot_img $boot_imglist" + fi fi for dir in $boot_dirlist; do @@ -668,6 +682,21 @@ prepare_kdump_bootinfo() done done + if ! [[ -e $KDUMP_KERNEL ]]; then + if [[ -n $debug_kernelver ]]; then + dinfo "Fallback to using debug kernel" + for dir in $boot_dirlist; do + for img in $debug_imglist; do + if [[ -f "$dir/$img" ]]; then + KDUMP_KERNEL=$(echo "$dir/$img" | tr -s '/') + KDUMP_KERNELVER="$debug_kernelver" + break 2 + fi + done + done + fi + fi + if ! [[ -e $KDUMP_KERNEL ]]; then derror "Failed to detect kdump kernel location" return 1 -- 2.27.0 _______________________________________________ kexec mailing list -- kexec(a)lists.fedoraproject.org To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure