From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm: oom_reaper: remove some bloat mmput_async is currently used only from the oom_reaper which is defined only for CONFIG_MMU. We can save work_struct in mm_struct for !CONFIG_MMU. [akpm@xxxxxxxxxxxxxxxxxxxx: fix typo, per Minchan] Link: http://lkml.kernel.org/r/20160520061658.GB19172@xxxxxxxxxxxxxx Reported-by: Minchan Kim <minchan@xxxxxxxxxx> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mm_types.h | 2 ++ include/linux/sched.h | 4 +++- kernel/fork.c | 2 ++ 3 files changed, 7 insertions(+), 1 deletion(-) diff -puN include/linux/mm_types.h~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix include/linux/mm_types.h --- a/include/linux/mm_types.h~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix +++ a/include/linux/mm_types.h @@ -514,7 +514,9 @@ struct mm_struct { #ifdef CONFIG_HUGETLB_PAGE atomic_long_t hugetlb_usage; #endif +#ifdef CONFIG_MMU struct work_struct async_put_work; +#endif }; static inline void mm_init_cpumask(struct mm_struct *mm) diff -puN include/linux/sched.h~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix include/linux/sched.h --- a/include/linux/sched.h~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix +++ a/include/linux/sched.h @@ -2745,10 +2745,12 @@ static inline bool mmget_not_zero(struct /* mmput gets rid of the mappings and all user-space */ extern void mmput(struct mm_struct *); -/* same as above but performs the slow path from the async kontext. Can +#ifdef CONFIG_MMU +/* same as above but performs the slow path from the async context. Can * be called from the atomic context as well */ extern void mmput_async(struct mm_struct *); +#endif /* Grab a reference to a task's mm, if it is not already going away */ extern struct mm_struct *get_task_mm(struct task_struct *task); diff -puN kernel/fork.c~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix kernel/fork.c --- a/kernel/fork.c~mm-oom_reaper-do-not-mmput-synchronously-from-the-oom-reaper-context-fix +++ a/kernel/fork.c @@ -736,6 +736,7 @@ void mmput(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(mmput); +#ifdef CONFIG_MMU static void mmput_async_fn(struct work_struct *work) { struct mm_struct *mm = container_of(work, struct mm_struct, async_put_work); @@ -749,6 +750,7 @@ void mmput_async(struct mm_struct *mm) schedule_work(&mm->async_put_work); } } +#endif /** * set_mm_exe_file - change a reference to the mm's executable file _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
