On Wed, Jul 4, 2018 at 5:25 AM, 禹舟键 <ufo19890607@xxxxxxxxx> wrote: > Hi Andy > The const char array need to be used by the new func > mem_cgroup_print_oom_context and some funcs in oom_kill.c in the > second patch. Did I understand correctly that the array is added by you in this solely patch? Did I understand correctly that it's used only in one module (oom_kill.c in new version)? If both are true, just move it to the C file. If you need a synchronization, a) put a comment, b) create another enum item (like FOO_BAR_MAX) at the end and use it in the array as a fixed size, > > Thanks > >> >> On Sat, Jun 30, 2018 at 7:38 PM, <ufo19890607@xxxxxxxxx> wrote: >> > From: yuzhoujian <yuzhoujian@xxxxxxxxxxxxxxx> >> > >> > 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 -- With Best Regards, Andy Shevchenko