Re: [PATCH v2 1/2] tools/xenstore: set oom score for xenstore daemon on Linux

[Julien Grall <julien@xxxxxxx>]

Hi Juergen,

On 08/06/2021 06:58, Juergen Gross wrote:
> Xenstored is absolutely mandatory for a Xen host and it can't be
> restarted, so being killed by OOM-killer in case of memory shortage is
> to be avoided.
>
> Set /proc/$pid/oom_score_adj (if available) to -500 in order to allow
> xenstored to use large amounts of memory without being killed.
>
> Make sure the pid file isn't a left-over from a previous run delete it
> before starting xenstored.
This sentence is a bit confusing to read. Do you mean "*To* make 
sure....*,* delete it before"?
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
> V2:
> - set oom score from launch script (Julien Grall)
> - split off open file descriptor limit setting (Julien Grall)
> ---
>   tools/hotplug/Linux/launch-xenstore.in | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/tools/hotplug/Linux/launch-xenstore.in 
> b/tools/hotplug/Linux/launch-xenstore.in
> index 019f9d6f4d..3ad71e3d08 100644
> --- a/tools/hotplug/Linux/launch-xenstore.in
> +++ b/tools/hotplug/Linux/launch-xenstore.in
> @@ -59,11 +59,14 @@ test -f @CONFIG_DIR@/@CONFIG_LEAF_DIR@/xencommons && . 
> @CONFIG_DIR@/@CONFIG_LEAF
>                 echo "No xenstored found"
>                 exit 1
>         }
> +       rm -f @XEN_RUN_DIR@/xenstored.pid
>   
>   	echo -n Starting $XENSTORED...
>         $XENSTORED --pid-file @XEN_RUN_DIR@/xenstored.pid $XENSTORED_ARGS
>   
>   	systemd-notify --booted 2>/dev/null || timeout_xenstore $XENSTORED || exit 1
> +       XS_PID=`cat @XEN_RUN_DIR@/xenstored.pid`
> +       echo -500 >/proc/$XS_PID/oom_score_adj
NIT: It would be worth considering to introduce a variable so this can 
be set from the configuration file.
With or without it:

Acked-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall