The patch titled Subject: mm, oom: refactor oom_kill_process() has been added to the -mm tree. Its filename is mm-oom-refactor-the-oom_kill_process-function.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-oom-refactor-the-oom_kill_process-function.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-oom-refactor-the-oom_kill_process-function.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Roman Gushchin <guro@xxxxxx> Subject: mm, oom: refactor oom_kill_process() Patch series "cgroup-aware OOM killer", v13. This patchset makes the OOM killer cgroup-aware. This patch (of 7): oom_kill_process() consists of two logical parts: the first one is responsible for considering task's children as a potential victim and printing the debug information. The second half is responsible for sending SIGKILL to all tasks sharing the mm struct with the given victim. This commit splits oom_kill_process() with an intention to re-use the the second half: __oom_kill_process(). The cgroup-aware OOM killer will kill multiple tasks belonging to the victim cgroup. We don't need to print the debug information for the each task, as well as play with task selection (considering task's children), so we can't use the existing oom_kill_process(). Link: http://lkml.kernel.org/r/20171130152824.1591-2-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/oom_kill.c | 123 +++++++++++++++++++++++++----------------------- 1 file changed, 65 insertions(+), 58 deletions(-) diff -puN mm/oom_kill.c~mm-oom-refactor-the-oom_kill_process-function mm/oom_kill.c --- a/mm/oom_kill.c~mm-oom-refactor-the-oom_kill_process-function +++ a/mm/oom_kill.c @@ -814,68 +814,12 @@ static bool task_will_free_mem(struct ta return ret; } -static void oom_kill_process(struct oom_control *oc, const char *message) +static void __oom_kill_process(struct task_struct *victim) { - struct task_struct *p = oc->chosen; - unsigned int points = oc->chosen_points; - struct task_struct *victim = p; - struct task_struct *child; - struct task_struct *t; + struct task_struct *p; struct mm_struct *mm; - unsigned int victim_points = 0; - static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, - DEFAULT_RATELIMIT_BURST); bool can_oom_reap = true; - /* - * If the task is already exiting, don't alarm the sysadmin or kill - * its children or threads, just give it access to memory reserves - * so it can die quickly - */ - task_lock(p); - if (task_will_free_mem(p)) { - mark_oom_victim(p); - wake_oom_reaper(p); - task_unlock(p); - put_task_struct(p); - return; - } - task_unlock(p); - - if (__ratelimit(&oom_rs)) - dump_header(oc, p); - - pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n", - message, task_pid_nr(p), p->comm, points); - - /* - * If any of p's children has a different mm and is eligible for kill, - * the one with the highest oom_badness() score is sacrificed for its - * parent. This attempts to lose the minimal amount of work done while - * still freeing memory. - */ - read_lock(&tasklist_lock); - for_each_thread(p, t) { - list_for_each_entry(child, &t->children, sibling) { - unsigned int child_points; - - if (process_shares_mm(child, p->mm)) - continue; - /* - * oom_badness() returns 0 if the thread is unkillable - */ - child_points = oom_badness(child, - oc->memcg, oc->nodemask, oc->totalpages); - if (child_points > victim_points) { - put_task_struct(victim); - victim = child; - victim_points = child_points; - get_task_struct(victim); - } - } - } - read_unlock(&tasklist_lock); - p = find_lock_task_mm(victim); if (!p) { put_task_struct(victim); @@ -949,6 +893,69 @@ static void oom_kill_process(struct oom_ } #undef K +static void oom_kill_process(struct oom_control *oc, const char *message) +{ + struct task_struct *p = oc->chosen; + unsigned int points = oc->chosen_points; + struct task_struct *victim = p; + struct task_struct *child; + struct task_struct *t; + unsigned int victim_points = 0; + static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + + /* + * If the task is already exiting, don't alarm the sysadmin or kill + * its children or threads, just give it access to memory reserves + * so it can die quickly + */ + task_lock(p); + if (task_will_free_mem(p)) { + mark_oom_victim(p); + wake_oom_reaper(p); + task_unlock(p); + put_task_struct(p); + return; + } + task_unlock(p); + + if (__ratelimit(&oom_rs)) + dump_header(oc, p); + + pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n", + message, task_pid_nr(p), p->comm, points); + + /* + * If any of p's children has a different mm and is eligible for kill, + * the one with the highest oom_badness() score is sacrificed for its + * parent. This attempts to lose the minimal amount of work done while + * still freeing memory. + */ + read_lock(&tasklist_lock); + for_each_thread(p, t) { + list_for_each_entry(child, &t->children, sibling) { + unsigned int child_points; + + if (process_shares_mm(child, p->mm)) + continue; + /* + * oom_badness() returns 0 if the thread is unkillable + */ + child_points = oom_badness(child, + oc->memcg, oc->nodemask, oc->totalpages); + if (child_points > victim_points) { + put_task_struct(victim); + victim = child; + victim_points = child_points; + get_task_struct(victim); + } + } + } + read_unlock(&tasklist_lock); + + __oom_kill_process(victim); +} + /* * Determines whether the kernel must panic because of the panic_on_oom sysctl. */ _ Patches currently in -mm which might be from guro@xxxxxx are mm-show-total-hugetlb-memory-consumption-in-proc-meminfo.patch mm-oom-refactor-the-oom_kill_process-function.patch mm-implement-mem_cgroup_scan_tasks-for-the-root-memory-cgroup.patch mm-oom-cgroup-aware-oom-killer.patch mm-oom-introduce-memoryoom_group.patch mm-oom-add-cgroup-v2-mount-option-for-cgroup-aware-oom-killer.patch mm-oom-docs-describe-the-cgroup-aware-oom-killer.patch cgroup-list-groupoom-in-cgroup-features.patch -- 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