The patch titled oom: move oom_adj to signal_struct has been removed from the -mm tree. Its filename was oom-move-oom_adj-to-signal_struct.patch This patch was dropped because an alternative patch was merged The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: oom: move oom_adj to signal_struct From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> The commit 2ff05b2b (oom: move oom_adj value) move oom_adj value to mm_struct. It is very good first step for sanitize OOM. However Paul Menage reported the commit makes regression to his job scheduler. Current OOM logic can kill OOM_DISABLED process. Why? His program has the code of similar to the following. ... set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */ ... if (vfork() == 0) { set_oom_adj(0); /* Invoked child can be killed */ execve("foo-bar-cmd") } .... vfork() parent and child are shared the same mm_struct. then above set_oom_adj(0) doesn't only change oom_adj for vfork() child, but also change oom_adj for vfork() parent. Then, vfork() parent (job scheduler) lost OOM immune and it was killed. Actually, fork-setting-exec idiom is very frequently used in userland program. We must not break this assumption. Therefore, this patch move oom_adj again. it will be moved signal_struct. it is truth per-process data place. Plus, Restored writing to /proc/pid/oom_adj for a kernel thread return success again. changing return value might make confusing to shell-script. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Paul Menage <menage@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/filesystems/proc.txt | 9 +--- fs/proc/base.c | 33 ++++++++------ include/linux/mm_types.h | 2 include/linux/sched.h | 2 kernel/fork.c | 3 - mm/oom_kill.c | 60 +++++++++++++++++++-------- 6 files changed, 70 insertions(+), 39 deletions(-) diff -puN Documentation/filesystems/proc.txt~oom-move-oom_adj-to-signal_struct Documentation/filesystems/proc.txt --- a/Documentation/filesystems/proc.txt~oom-move-oom_adj-to-signal_struct +++ a/Documentation/filesystems/proc.txt @@ -1181,12 +1181,11 @@ CHAPTER 3: PER-PROCESS PARAMETERS ------------------------------------------------------ This file can be used to adjust the score used to select which processes should -be killed in an out-of-memory situation. The oom_adj value is a characteristic -of the task's mm, so all threads that share an mm with pid will have the same +be killed in an out-of-memory situation. All threads in the process will have the same oom_adj value. A high value will increase the likelihood of this process being killed by the oom-killer. Valid values are in the range -16 to +15 as explained below and a special value of -17, which disables oom-killing -altogether for threads sharing pid's mm. +altogether the process. The process to be killed in an out-of-memory situation is selected among all others based on its badness score. This value equals the original memory size of the process @@ -1200,8 +1199,8 @@ the parent's score if they do not share are the prime candidates to be killed. Having only one 'hungry' child will make parent less preferable than the child. -/proc/<pid>/oom_adj cannot be changed for kthreads since they are immune from -oom-killing already. +/proc/<pid>/oom_adj can be changed for kthreads, but it's meaningless. They are immune from +oom-killing. /proc/<pid>/oom_score shows process' current badness score. diff -puN fs/proc/base.c~oom-move-oom_adj-to-signal_struct fs/proc/base.c --- a/fs/proc/base.c~oom-move-oom_adj-to-signal_struct +++ a/fs/proc/base.c @@ -1001,16 +1001,17 @@ static ssize_t oom_adjust_read(struct fi struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode); char buffer[PROC_NUMBUF]; size_t len; - int oom_adjust; + int oom_adjust = OOM_DISABLE; + unsigned long flags; if (!task) return -ESRCH; - task_lock(task); - if (task->mm) - oom_adjust = task->mm->oom_adj; - else - oom_adjust = OOM_DISABLE; - task_unlock(task); + + if (lock_task_sighand(task, &flags)) { + oom_adjust = task->signal->oom_adj; + unlock_task_sighand(task, &flags); + } + put_task_struct(task); len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust); @@ -1024,6 +1025,7 @@ static ssize_t oom_adjust_write(struct f struct task_struct *task; char buffer[PROC_NUMBUF], *end; int oom_adjust; + unsigned long flags; memset(buffer, 0, sizeof(buffer)); if (count > sizeof(buffer) - 1) @@ -1039,19 +1041,20 @@ static ssize_t oom_adjust_write(struct f task = get_proc_task(file->f_path.dentry->d_inode); if (!task) return -ESRCH; - task_lock(task); - if (!task->mm) { - task_unlock(task); + + if (!lock_task_sighand(task, &flags)) { put_task_struct(task); - return -EINVAL; + return -ESRCH; } - if (oom_adjust < task->mm->oom_adj && !capable(CAP_SYS_RESOURCE)) { - task_unlock(task); + + if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) { + unlock_task_sighand(task, &flags); put_task_struct(task); return -EACCES; } - task->mm->oom_adj = oom_adjust; - task_unlock(task); + + task->signal->oom_adj = oom_adjust; + unlock_task_sighand(task, &flags); put_task_struct(task); if (end - buffer == 0) return -EIO; diff -puN include/linux/mm_types.h~oom-move-oom_adj-to-signal_struct include/linux/mm_types.h --- a/include/linux/mm_types.h~oom-move-oom_adj-to-signal_struct +++ a/include/linux/mm_types.h @@ -240,8 +240,6 @@ struct mm_struct { unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ - s8 oom_adj; /* OOM kill score adjustment (bit shift) */ - cpumask_t cpu_vm_mask; /* Architecture-specific MM context */ diff -puN include/linux/sched.h~oom-move-oom_adj-to-signal_struct include/linux/sched.h --- a/include/linux/sched.h~oom-move-oom_adj-to-signal_struct +++ a/include/linux/sched.h @@ -652,6 +652,8 @@ struct signal_struct { unsigned audit_tty; struct tty_audit_buf *tty_audit_buf; #endif + + int oom_adj; /* OOM kill score adjustment (bit shift) */ }; /* Context switch must be unlocked if interrupts are to be enabled */ diff -puN kernel/fork.c~oom-move-oom_adj-to-signal_struct kernel/fork.c --- a/kernel/fork.c~oom-move-oom_adj-to-signal_struct +++ a/kernel/fork.c @@ -448,7 +448,6 @@ static struct mm_struct * mm_init(struct INIT_LIST_HEAD(&mm->mmlist); mm->flags = (current->mm) ? (current->mm->flags & MMF_INIT_MASK) : default_dump_filter; - mm->oom_adj = (current->mm) ? current->mm->oom_adj : 0; mm->core_state = NULL; mm->nr_ptes = 0; set_mm_counter(mm, file_rss, 0); @@ -890,6 +889,8 @@ static int copy_signal(unsigned long clo tty_audit_fork(sig); + sig->oom_adj = current->signal->oom_adj; + return 0; } diff -puN mm/oom_kill.c~oom-move-oom_adj-to-signal_struct mm/oom_kill.c --- a/mm/oom_kill.c~oom-move-oom_adj-to-signal_struct +++ a/mm/oom_kill.c @@ -34,6 +34,31 @@ int sysctl_oom_dump_tasks; static DEFINE_SPINLOCK(zone_scan_lock); /* #define DEBUG */ +int get_oom_adj(struct task_struct *tsk) +{ + unsigned long flags; + int oom_adj = OOM_DISABLE; + + if (tsk->mm && lock_task_sighand(tsk, &flags)) { + oom_adj = tsk->signal->oom_adj; + unlock_task_sighand(tsk, &flags); + } + + return oom_adj; +} + +void set_oom_adj(struct task_struct *tsk, int oom_adj) +{ + unsigned long flags; + + if (lock_task_sighand(tsk, &flags)) { + tsk->signal->oom_adj = oom_adj; + unlock_task_sighand(tsk, &flags); + } +} + + + /** * badness - calculate a numeric value for how bad this task has been * @p: task struct of which task we should calculate @@ -60,17 +85,16 @@ unsigned long badness(struct task_struct struct task_struct *child; int oom_adj; + oom_adj = get_oom_adj(p); + if (oom_adj == OOM_DISABLE) + return 0; + task_lock(p); mm = p->mm; if (!mm) { task_unlock(p); return 0; } - oom_adj = mm->oom_adj; - if (oom_adj == OOM_DISABLE) { - task_unlock(p); - return 0; - } /* * The memory size of the process is the basis for the badness. @@ -283,6 +307,8 @@ static struct task_struct *select_bad_pr static void dump_tasks(const struct mem_cgroup *mem) { struct task_struct *g, *p; + unsigned long flags; + int oom_adj; printk(KERN_INFO "[ pid ] uid tgid total_vm rss cpu oom_adj " "name\n"); @@ -294,6 +320,12 @@ static void dump_tasks(const struct mem_ if (!thread_group_leader(p)) continue; + if (!lock_task_sighand(p, &flags)) + continue; + + oom_adj = p->signal->oom_adj; + unlock_task_sighand(p, &flags); + task_lock(p); mm = p->mm; if (!mm) { @@ -307,7 +339,7 @@ static void dump_tasks(const struct mem_ } printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm, - get_mm_rss(mm), (int)task_cpu(p), mm->oom_adj, p->comm); + get_mm_rss(mm), (int)task_cpu(p), oom_adj, p->comm); task_unlock(p); } while_each_thread(g, p); } @@ -345,16 +377,11 @@ static void __oom_kill_task(struct task_ static int oom_kill_task(struct task_struct *p) { - struct mm_struct *mm; struct task_struct *g, *q; - task_lock(p); - mm = p->mm; - if (!mm || mm->oom_adj == OOM_DISABLE) { - task_unlock(p); + if (get_oom_adj(p) == OOM_DISABLE) return 1; - } - task_unlock(p); + __oom_kill_task(p, 1); /* @@ -363,7 +390,7 @@ static int oom_kill_task(struct task_str * to memory reserves though, otherwise we might deplete all memory. */ do_each_thread(g, q) { - if (q->mm == mm && !same_thread_group(q, p)) + if (q->mm == p->mm && !same_thread_group(q, p)) force_sig(SIGKILL, q); } while_each_thread(g, q); @@ -377,11 +404,12 @@ static int oom_kill_process(struct task_ struct task_struct *c; if (printk_ratelimit()) { + int oom_adj = get_oom_adj(current); + task_lock(current); printk(KERN_WARNING "%s invoked oom-killer: " "gfp_mask=0x%x, order=%d, oom_adj=%d\n", - current->comm, gfp_mask, order, - current->mm ? current->mm->oom_adj : OOM_DISABLE); + current->comm, gfp_mask, order, oom_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); dump_stack(); _ Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are origin.patch mm-revert-oom-move-oom_adj-value.patch linux-next.patch readahead-add-blk_run_backing_dev.patch readahead-add-blk_run_backing_dev-fix.patch readahead-add-blk_run_backing_dev-fix-fix-2.patch mm-clean-up-page_remove_rmap.patch mm-show_free_areas-display-slab-pages-in-two-separate-fields.patch mm-oom-analysis-add-per-zone-statistics-to-show_free_areas.patch mm-oom-analysis-add-buffer-cache-information-to-show_free_areas.patch mm-oom-analysis-show-kernel-stack-usage-in-proc-meminfo-and-oom-log-output.patch mm-oom-analysis-add-shmem-vmstat.patch mm-rename-pgmoved-variable-in-shrink_active_list.patch mm-shrink_inactive_list-nr_scan-accounting-fix-fix.patch mm-vmstat-add-isolate-pages.patch mm-vmstat-add-isolate-pages-fix.patch vmscan-throttle-direct-reclaim-when-too-many-pages-are-isolated-already.patch mm-remove-__addsub_zone_page_state.patch mm-count-only-reclaimable-lru-pages-v2.patch vmscan-dont-attempt-to-reclaim-anon-page-in-lumpy-reclaim-when-no-swap-space-is-avilable.patch vmscan-move-clearpageactive-from-move_active_pages-to-shrink_active_list.patch vmscan-kill-unnecessary-page-flag-test.patch vmscan-kill-unnecessary-prefetch.patch mm-perform-non-atomic-test-clear-of-pg_mlocked-on-free.patch oom-move-oom_adj-to-signal_struct.patch oom-make-oom_score-to-per-process-value.patch oom-oom_kill-doesnt-kill-vfork-parentor-child.patch oom-fix-oom_adjust_write-input-sanity-check.patch oom-fix-oom_adjust_write-input-sanity-check-fix.patch tracing-page-allocator-add-trace-events-for-page-allocation-and-page-freeing.patch tracing-page-allocator-add-trace-event-for-page-traffic-related-to-the-buddy-lists.patch getrusage-fill-ru_maxrss-value.patch getrusage-fill-ru_maxrss-value-update.patch memory-controller-soft-limit-documentation-v9.patch memory-controller-soft-limit-interface-v9.patch memory-controller-soft-limit-organize-cgroups-v9.patch memory-controller-soft-limit-organize-cgroups-v9-fix.patch memory-controller-soft-limit-refactor-reclaim-flags-v9.patch memory-controller-soft-limit-reclaim-on-contention-v9.patch memory-controller-soft-limit-reclaim-on-contention-v9-fix.patch memcg-improve-resource-counter-scalability.patch fs-symlink-write_begin-allocation-context-fix-reiser4-fix.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