linux_dsm_epyc7002/include/linux/oom.h
Michal Hocko 1af8bb4326 mm, oom: fortify task_will_free_mem()
task_will_free_mem is rather weak.  It doesn't really tell whether the
task has chance to drop its mm.  98748bd722 ("oom: consider
multi-threaded tasks in task_will_free_mem") made a first step into making
it more robust for multi-threaded applications so now we know that the
whole process is going down and probably drop the mm.

This patch builds on top for more complex scenarios where mm is shared
between different processes - CLONE_VM without CLONE_SIGHAND, or in kernel
use_mm().

Make sure that all processes sharing the mm are killed or exiting.  This
will allow us to replace try_oom_reaper by wake_oom_reaper because
task_will_free_mem implies the task is reapable now.  Therefore all paths
which bypass the oom killer are now reapable and so they shouldn't lock up
the oom killer.

Link: http://lkml.kernel.org/r/1466426628-15074-8-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00

117 lines
2.9 KiB
C

#ifndef __INCLUDE_LINUX_OOM_H
#define __INCLUDE_LINUX_OOM_H
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/nodemask.h>
#include <uapi/linux/oom.h>
struct zonelist;
struct notifier_block;
struct mem_cgroup;
struct task_struct;
/*
* Details of the page allocation that triggered the oom killer that are used to
* determine what should be killed.
*/
struct oom_control {
/* Used to determine cpuset */
struct zonelist *zonelist;
/* Used to determine mempolicy */
nodemask_t *nodemask;
/* Memory cgroup in which oom is invoked, or NULL for global oom */
struct mem_cgroup *memcg;
/* Used to determine cpuset and node locality requirement */
const gfp_t gfp_mask;
/*
* order == -1 means the oom kill is required by sysrq, otherwise only
* for display purposes.
*/
const int order;
};
/*
* Types of limitations to the nodes from which allocations may occur
*/
enum oom_constraint {
CONSTRAINT_NONE,
CONSTRAINT_CPUSET,
CONSTRAINT_MEMORY_POLICY,
CONSTRAINT_MEMCG,
};
enum oom_scan_t {
OOM_SCAN_OK, /* scan thread and find its badness */
OOM_SCAN_CONTINUE, /* do not consider thread for oom kill */
OOM_SCAN_ABORT, /* abort the iteration and return */
OOM_SCAN_SELECT, /* always select this thread first */
};
extern struct mutex oom_lock;
static inline void set_current_oom_origin(void)
{
current->signal->oom_flag_origin = true;
}
static inline void clear_current_oom_origin(void)
{
current->signal->oom_flag_origin = false;
}
static inline bool oom_task_origin(const struct task_struct *p)
{
return p->signal->oom_flag_origin;
}
extern void mark_oom_victim(struct task_struct *tsk);
#ifdef CONFIG_MMU
extern void wake_oom_reaper(struct task_struct *tsk);
#else
static inline void wake_oom_reaper(struct task_struct *tsk)
{
}
#endif
extern unsigned long oom_badness(struct task_struct *p,
struct mem_cgroup *memcg, const nodemask_t *nodemask,
unsigned long totalpages);
extern void oom_kill_process(struct oom_control *oc, struct task_struct *p,
unsigned int points, unsigned long totalpages,
const char *message);
extern void check_panic_on_oom(struct oom_control *oc,
enum oom_constraint constraint);
extern enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
struct task_struct *task);
extern bool out_of_memory(struct oom_control *oc);
extern void exit_oom_victim(struct task_struct *tsk);
extern int register_oom_notifier(struct notifier_block *nb);
extern int unregister_oom_notifier(struct notifier_block *nb);
extern bool oom_killer_disabled;
extern bool oom_killer_disable(void);
extern void oom_killer_enable(void);
extern struct task_struct *find_lock_task_mm(struct task_struct *p);
bool task_will_free_mem(struct task_struct *task);
/* sysctls */
extern int sysctl_oom_dump_tasks;
extern int sysctl_oom_kill_allocating_task;
extern int sysctl_panic_on_oom;
#endif /* _INCLUDE_LINUX_OOM_H */