Re: [PATCH] mm, oom: enable rate-limiting controls for oom dumps

[Michal Hocko <mhocko@suse.com>]

On Fri 09-10-20 11:30:14, Ricardo Cañuelo wrote:
> Add two sysctl entries (vm.oom_dump_ratelimit and
> vm.oom_dump_ratelimit_burst) to control the rate limiting interval and
> burst, respectively, of the OOM killer output (oom_kill_process()).
> 
> These entries are disabled by default and can be enabled during kernel
> configuration with CONFIG_DUMP_RATELIMIT. They take
> DEFAULT_RATELIMIT_INTERVAL and DEFAULT_RATELIMIT_BURST as their default
> values.
> 
> Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
> ---
> 
> In some setups, the amount of output that the OOM killer generates when
> it kills a process and dumps the list of tasks can be too
> large. Unfortunately, the rate-limiting used for it uses the default
> values for the rate limit interval and burst. This patch allows the user
> to configure these values.

How does controling burst and interval solve the problem? Btw. this
should be a part of the changelog which should explain not only what but
also why the change is needed.

It is true that the oom report can generate a lot of output. This is
something that is brought up for quite some time. The largest part of
the output tends to be the list of tasks and this seems to be the case
for you as well. Is the list of tasks so important that you need to have
it in the log? If not you can simply disable this part of the log
altogether by /proc/sys/vm/oom_dump_tasks.
-- 
Michal Hocko
SUSE Labs