Re: [PATCH v2] kdump: fix OOM issue when vm.min_free_kbytes is set too high

[Dave Young]

On 12/09/14 at 05:36pm, Dave Young wrote:
>  On 12/08/14 at 10:57am, Hari Bathini wrote:
>  > When the value of vm.min_free_kbytes is set too high in /etc/sysctl.conf,
>  > kdump kernel fails with OOM. As min_free_kbytes may not be relevant for
>  > kdump kernel, this patch tries to fix the issue by removing it from the
>  > file sysctl.conf and thus forcing default value for vm.min_free_kbytes
>  > parameter.
>  > 
>  > Changes from v1 to v2:
>  > 1. Moved snippet modifying /etc/sysctl.conf file to a new function
>  > 2. Removed unnecessary expressions while modifying sysctl.conf
>  > 
>  > Signed-off-by: Hari Bathini <hbathini(a)linux.vnet.ibm.com&gt;
>  > ---
>  >  dracut-module-setup.sh |   11 +++++++++++
>  >  1 file changed, 11 insertions(+)
>  > 
>  > diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>  > index dcebc47..72871d0 100755
>  > --- a/dracut-module-setup.sh
>  > +++ b/dracut-module-setup.sh
>  > @@ -378,6 +378,16 @@ kdump_install_conf() {
>  >      rm -f /tmp/$$-kdump.conf
>  >  }
>  >  
>  > +# Certain things configured in /etc/sysctl.conf are not relevant
>  > +# for kdump kernel. Tune them here
>  > +kdump_sysctl_conf() {
>  > +
>  > +    # While min_free_kbytes may not be relevant for kdump kernel,
>  > +    # it leads to OOM in cases where this value is too high.
>  > +    # Let's be paranoid and force it to default value calculated by kernel.
>  > +    sed -e "/min_free_kbytes/d" /etc/sysctl.conf >
> "${initdir}/etc/sysctl.conf"
>  > +}
>  > +
>  >  kdump_iscsi_get_rec_val() {
>  >  
>  >      local result
>  > @@ -586,6 +596,7 @@ kdump_install_random_seed() {
>  >  
>  >  install() {
>  >      kdump_install_conf
>  > +    kdump_sysctl_conf
>  >  
>  >      if is_ssh_dump_target; then
>  >          kdump_install_random_seed
>  > 
>  
>  ACK 
self NACK, I meant to ack the patch for rm sysctl*

>  
>  Thanks
>  Dave