On Mon 21-05-18 03:39:46, ufo19890607 wrote: > From: yuzhoujian <[email protected]> > > The dump_header does not print the memcg's name when the system > oom happened. So users cannot locate the certain container which > contains the task that has been killed by the oom killer. > > System oom report will print the memcg's name after this patch, > so users can get the memcg's path from the oom report and check > the certain container more quickly. > > Changes since v3: > - rename the helper's name to mem_cgroup_print_oom_memcg_name. > - add the rcu lock held to the helper. > - remove the print info of memcg's name in mem_cgroup_print_oom_info. > > Changes since v2: > - add the mem_cgroup_print_memcg_name helper to print the memcg's > name which contains the task that will be killed by the oom-killer. > > Changes since v1: > - replace adding mem_cgroup_print_oom_info with printing the memcg's > name only.
This has still the part which is misleading in the global oom context. So no, it seems that a helper will not do much good. Unless we can squeeze everything into a single like like David proposed (http://lkml.kernel.org/r/[email protected]) we should simply open code the relevant part of in the global oom path. > Signed-off-by: yuzhoujian <[email protected]> > --- > include/linux/memcontrol.h | 9 +++++++++ > mm/memcontrol.c | 27 +++++++++++++++++++-------- > mm/oom_kill.c | 1 + > 3 files changed, 29 insertions(+), 8 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index d99b71bc2c66..5fc58beae368 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -464,6 +464,9 @@ void mem_cgroup_handle_over_high(void); > > unsigned long mem_cgroup_get_limit(struct mem_cgroup *memcg); > > +void mem_cgroup_print_oom_memcg_name(struct mem_cgroup *memcg, > + struct task_struct *p); > + > void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, > struct task_struct *p); > > @@ -858,6 +861,12 @@ static inline unsigned long mem_cgroup_get_limit(struct > mem_cgroup *memcg) > return 0; > } > > +static inline void > +mem_cgroup_print_oom_memcg_name(struct mem_cgroup *memcg, > + struct task_struct *p) > +{ > +} > + > static inline void > mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p) > { > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 2bd3df3d101a..138a11edfacb 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1118,19 +1118,15 @@ static const char *const memcg1_stat_names[] = { > }; > > #define K(x) ((x) << (PAGE_SHIFT-10)) > + > /** > - * mem_cgroup_print_oom_info: Print OOM information relevant to memory > controller. > + * mem_cgroup_print_oom_memcg_name: Print the memcg's name which contains the > + * task that will be killed by the oom-killer. > * @memcg: The memory cgroup that went over limit > * @p: Task that is going to be killed > - * > - * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is > - * enabled > */ > -void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct > *p) > +void mem_cgroup_print_oom_memcg_name(struct mem_cgroup *memcg, struct > task_struct *p) > { > - struct mem_cgroup *iter; > - unsigned int i; > - > rcu_read_lock(); > > if (p) { > @@ -1145,7 +1141,22 @@ void mem_cgroup_print_oom_info(struct mem_cgroup > *memcg, struct task_struct *p) > pr_cont("\n"); > > rcu_read_unlock(); > +} > + > +/** > + * mem_cgroup_print_oom_info: Print OOM information relevant to memory > controller. > + * @memcg: The memory cgroup that went over limit > + * @p: Task that is going to be killed > + * > + * NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is > + * enabled > + */ > +void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct > *p) > +{ > + struct mem_cgroup *iter; > + unsigned int i; > > + mem_cgroup_print_oom_memcg_name(memcg, p); > pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n", > K((u64)page_counter_read(&memcg->memory)), > K((u64)memcg->memory.limit), memcg->memory.failcnt); > diff --git a/mm/oom_kill.c b/mm/oom_kill.c > index 8ba6cb88cf58..3e0b725fb877 100644 > --- a/mm/oom_kill.c > +++ b/mm/oom_kill.c > @@ -433,6 +433,7 @@ static void dump_header(struct oom_control *oc, struct > task_struct *p) > if (is_memcg_oom(oc)) > mem_cgroup_print_oom_info(oc->memcg, p); > else { > + mem_cgroup_print_oom_memcg_name(oc->memcg, p); > show_mem(SHOW_MEM_FILTER_NODES, oc->nodemask); > if (is_dump_unreclaim_slabs()) > dump_unreclaimable_slab(); > -- > 2.14.1 -- Michal Hocko SUSE Labs
