Re: [PATCH v2 9/9] mm, oom: print symbolic gfp_flags in oom warning

Michal Hocko
2015-11-25T14:31:58Z

On Tue 24-11-15 13:36:21, Vlastimil Babka wrote:
> It would be useful to translate gfp_flags into string representation when
> printing in case of an OOM, especially as the flags have been undergoing some
> changes recently and the script ./scripts/gfp-translate needs a matching source
> version to be accurate.
>
> Example output:
>
> a.out invoked oom-killer: order=0, oom_score_adj=0, gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|GFP_ZERO)

I like this _very much_

> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

If this can be done with a printk formatter it would be even nicer but
this is good enough for the OOM purpose.

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> mm/oom_kill.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index 5314b20..542d56c 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -386,10 +386,12 @@ static void dump_tasks(struct mem_cgroup *memcg, const nodemask_t *nodemask)
> static void dump_header(struct oom_control *oc, struct task_struct *p,
> struct mem_cgroup *memcg)
> {
> - pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, "
> - "oom_score_adj=%hd\n",
> - current->comm, oc->gfp_mask, oc->order,
> - current->signal->oom_score_adj);
> + pr_warning("%s invoked oom-killer: order=%d, oom_score_adj=%hd, "
> + "gfp_mask=0x%x",
> + current->comm, oc->order, current->signal->oom_score_adj,
> + oc->gfp_mask);
> + dump_gfpflag_names(oc->gfp_mask);
> +
> cpuset_print_current_mems_allowed();
> dump_stack();
> if (memcg)
> --
> 2.6.3

--
Michal Hocko
SUSE Labs