Re: [PATCH v11 1/2] Refactor part of the oom report in dump_header

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Sat, Jun 30, 2018 at 7:38 PM,  <ufo19890607@gmail.com> wrote:
> From: yuzhoujian <yuzhoujian@didichuxing.com>
>
> The current system wide oom report prints information about the victim
> and the allocation context and restrictions. It, however, doesn't
> provide any information about memory cgroup the victim belongs to. This
> information can be interesting for container users because they can find
> the victim's container much more easily.
>
> I follow the advices of David Rientjes and Michal Hocko, and refactor
> part of the oom report. After this patch, users can get the memcg's
> path from the oom report and check the certain container more quickly.
>
> The oom print info after this patch:
> oom-kill:constraint=<constraint>,nodemask=<nodemask>,oom_memcg=<memcg>,task_memcg=<memcg>,task=<comm>,pid=<pid>,uid=<uid>


> +static const char * const oom_constraint_text[] = {
> +       [CONSTRAINT_NONE] = "CONSTRAINT_NONE",
> +       [CONSTRAINT_CPUSET] = "CONSTRAINT_CPUSET",
> +       [CONSTRAINT_MEMORY_POLICY] = "CONSTRAINT_MEMORY_POLICY",
> +       [CONSTRAINT_MEMCG] = "CONSTRAINT_MEMCG",
> +};

I'm not sure why we have this in the header.

This produces a lot of noise when W=1.

In file included from
/home/andy/prj/linux-topic-mfld/include/linux/memcontrol.h:31:0,
                from /home/andy/prj/linux-topic-mfld/include/net/sock.h:58,
                from /home/andy/prj/linux-topic-mfld/include/linux/tcp.h:23,
                from /home/andy/prj/linux-topic-mfld/include/linux/ipv6.h:87,
                from /home/andy/prj/linux-topic-mfld/include/net/ipv6.h:16,
                from
/home/andy/prj/linux-topic-mfld/net/ipv4/netfilter/nf_log_ipv4.c:17:
/home/andy/prj/linux-topic-mfld/include/linux/oom.h:32:27: warning:
‘oom_constraint_text’ defined but not used [-W
unused-const-variable=]
static const char * const oom_constraint_text[] = {
                          ^~~~~~~~~~~~~~~~~~~
 CC [M]  net/ipv4/netfilter/iptable_nat.o


If you need (but looking at the code you actually don't if I didn't
miss anything) it in several places, just export.
Otherwise put it back to memcontrol.c.

-- 
With Best Regards,
Andy Shevchenko