Re: [PATCH] Revert "Always set vm.zone_reclaim_mode = 3 in kdump kernel"

[piliu]

On 4/19/21 11:00 PM, Kairui Song wrote:
>  This reverts commit 5633e8331866098c97e72e99f233a254fa479a4d.
>  
>  vm.zone_reclaim_mode may cause trashing on some machines. And after
>  second thought, vm.zone_reclaim_mode is barely helpful for machines
>  with high mem stress, so just revert it.
>  ---
>    dracut-module-setup.sh | 12 +++++-------
>    1 file changed, 5 insertions(+), 7 deletions(-)
>  
>  diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>  index 066d0ce..b32b39b 100755
>  --- a/dracut-module-setup.sh
>  +++ b/dracut-module-setup.sh
>  @@ -645,18 +645,16 @@ kdump_install_conf() {
>        rm -f ${initdir}/tmp/$$-kdump.conf
>    }
>    
>  -# Remove user custom configurations sysctl.conf & sysctl.d/*
>  -# and apply some optimization for kdump
>  -overwrite_sysctl_conf() {
>  +# Default sysctl parameters should suffice for kdump kernel.
>  +# Remove custom configurations sysctl.conf & sysctl.d/*
>  +remove_sysctl_conf() {
>  +
>        # As custom configurations like vm.min_free_kbytes can lead
>        # to OOM issues in kdump kernel, avoid them
>        rm -f "${initdir}/etc/sysctl.conf"
>        rm -rf "${initdir}/etc/sysctl.d"
>        rm -rf "${initdir}/run/sysctl.d"
>        rm -rf "${initdir}/usr/lib/sysctl.d"
>  -
>  -    mkdir -p "${initdir}/etc/sysctl.d"
>  -    echo "vm.zone_reclaim_mode = 3" >
> "${initdir}/etc/sysctl.d/99-zone-reclaim.conf"
>    }
>    
>    kdump_iscsi_get_rec_val() {
>  @@ -947,7 +945,7 @@ kdump_install_systemd_conf() {
>    install() {
>        kdump_module_init
>        kdump_install_conf
>  -    overwrite_sysctl_conf
>  +    remove_sysctl_conf
>    
>        if is_ssh_dump_target; then
>            kdump_install_random_seed
>   
Acked-by: Pingfan Liu <piliu(a)redhat.com&gt;