One of the largest chunks of log messages in a OOM is from dump_stack() and in some cases it isn't even necessary to figure out what's going on. In systems with multiple tenants/containers with limited resources each OOMs can be way more frequent and being able to reduce the amount of log output for each situation is useful.
This patch adds a sysctl to allow disabling dump_stack() during an OOM while keeping the default to behave the same way it behaves today. Cc: Greg Thelen <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Aristeu Rozanski <[email protected]> --- include/linux/oom.h | 1 + kernel/sysctl.c | 7 +++++++ mm/oom_kill.c | 4 +++- 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/linux/oom.h b/include/linux/oom.h index 03e6257..bdd03e5 100644 --- a/include/linux/oom.h +++ b/include/linux/oom.h @@ -115,6 +115,7 @@ static inline bool task_will_free_mem(struct task_struct *task) /* sysctls */ extern int sysctl_oom_dump_tasks; +extern int sysctl_oom_dump_stack; extern int sysctl_oom_kill_allocating_task; extern int sysctl_panic_on_oom; #endif /* _INCLUDE_LINUX_OOM_H */ diff --git a/kernel/sysctl.c b/kernel/sysctl.c index e69201d..c812523 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1176,6 +1176,13 @@ static struct ctl_table vm_table[] = { .proc_handler = proc_dointvec, }, { + .procname = "oom_dump_stack", + .data = &sysctl_oom_dump_stack, + .maxlen = sizeof(sysctl_oom_dump_stack), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { .procname = "overcommit_ratio", .data = &sysctl_overcommit_ratio, .maxlen = sizeof(sysctl_overcommit_ratio), diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 1ecc0bc..bdbf83b 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -42,6 +42,7 @@ int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; int sysctl_oom_dump_tasks = 1; +int sysctl_oom_dump_stack = 1; DEFINE_MUTEX(oom_lock); @@ -384,7 +385,8 @@ static void dump_header(struct oom_control *oc, struct task_struct *p, current->signal->oom_score_adj); cpuset_print_task_mems_allowed(current); task_unlock(current); - dump_stack(); + if (sysctl_oom_dump_stack) + dump_stack(); if (memcg) mem_cgroup_print_oom_info(memcg, p); else -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
