On Fri, Dec 05, 2014 at 09:57:41PM +0530, Hari Bathini wrote:
On 12/05/2014 08:41 PM, Vivek Goyal wrote:
>On Tue, Nov 25, 2014 at 11:42:20AM +0530, 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.
>>
>>Signed-off-by: Hari Bathini <hbathini(a)linux.vnet.ibm.com>
>>---
>> dracut-module-setup.sh | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>>diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
>>index dcebc47..6ada7d3 100755
>>--- a/dracut-module-setup.sh
>>+++ b/dracut-module-setup.sh
>>@@ -612,6 +612,11 @@ install() {
>> # Also redirect dracut-emergency to kdump error handler
>> ln_r "$systemdsystemunitdir/emergency.service"
"$systemdsystemunitdir/dracut-emergency.service"
>>+ # 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 in kernel.
>>+ sed -e "/^$/d" -e "/^#/d" -e
"/min_free_kbytes/d" /etc/sysctl.conf >
"${initdir}/etc/sysctl.conf"
>Hari,
>
>which service inside dracut applies forces these parameters? It does
>sound like a problem in kdump environment because lot of these settings
>might make sense in first kernel (when all cpus and memory is available)
>but might not make sense in second kernel.
>
>It would be preferrable if we can override those settings based on user
>inputs instead of hardcoding these. Having said that I am not finding
>any way to do that.
>
>So I guess for the time being we can take this patch. If more problems
>like this crop up, we might have to request dracut guys to provide us
>a command line option where sysctl options can be specified and user
>will need to provide those command line options.
>
>
>So I guess for the time being we can take this patch. If more problems
>like this crop up, we might have to request dracut guys to provide us
>a command line option where sysctl options can be specified and user
>will need to provide those command line options.
>
>w.r.t patch, what are expressions "-e "/^$/d"" and -e
"/^#/d"?
Since we are here, thought of cleaning the sysctl.conf file in kdump initrd
by deleting empty lines and comment lines respectively, as done for
kdump.conf file
Ok, I don't think it was required but I am not particular about it. So..
Acked-by: Vivek Goyal <vgoyal(a)redhat.com>
Thanks
Vivek