From 1b604d75bbb6e28628c5a95a433432973c33d581 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Mon, 14 Dec 2009 17:57:47 -0800 Subject: [PATCH] oom: dump stack and VM state when oom killer panics The oom killer header, including information such as the allocation order and gfp mask, current's cpuset and memory controller, call trace, and VM state information is currently only shown when the oom killer has selected a task to kill. This information is omitted, however, when the oom killer panics either because of panic_on_oom sysctl settings or when no killable task was found. It is still relevant to know crucial pieces of information such as the allocation order and VM state when diagnosing such issues, especially at boot. This patch displays the oom killer header whenever it panics so that bug reports can include pertinent information to debug the issue, if possible. Signed-off-by: David Rientjes Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/oom_kill.c | 40 ++++++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 16 deletions(-) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index ea2147dabba60..492c98624fc19 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -337,6 +337,21 @@ static void dump_tasks(const struct mem_cgroup *mem) } while_each_thread(g, p); } +static void dump_header(gfp_t gfp_mask, int order, struct mem_cgroup *mem) +{ + pr_warning("%s invoked oom-killer: gfp_mask=0x%x, order=%d, " + "oom_adj=%d\n", + current->comm, gfp_mask, order, current->signal->oom_adj); + task_lock(current); + cpuset_print_task_mems_allowed(current); + task_unlock(current); + dump_stack(); + mem_cgroup_print_oom_info(mem, current); + show_mem(); + if (sysctl_oom_dump_tasks) + dump_tasks(mem); +} + /* * Send SIGKILL to the selected process irrespective of CAP_SYS_RAW_IO * flag though it's unlikely that we select a process with CAP_SYS_RAW_IO @@ -395,20 +410,8 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order, { struct task_struct *c; - if (printk_ratelimit()) { - printk(KERN_WARNING "%s invoked oom-killer: " - "gfp_mask=0x%x, order=%d, oom_adj=%d\n", - current->comm, gfp_mask, order, - current->signal->oom_adj); - task_lock(current); - cpuset_print_task_mems_allowed(current); - task_unlock(current); - dump_stack(); - mem_cgroup_print_oom_info(mem, current); - show_mem(); - if (sysctl_oom_dump_tasks) - dump_tasks(mem); - } + if (printk_ratelimit()) + dump_header(gfp_mask, order, mem); /* * If the task is already exiting, don't alarm the sysadmin or kill @@ -544,6 +547,7 @@ retry: /* Found nothing?!?! Either we hang forever, or we panic. */ if (!p) { read_unlock(&tasklist_lock); + dump_header(gfp_mask, order, NULL); panic("Out of memory and no killable processes...\n"); } @@ -609,8 +613,10 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order) /* Got some memory back in the last second. */ return; - if (sysctl_panic_on_oom == 2) + if (sysctl_panic_on_oom == 2) { + dump_header(gfp_mask, order, NULL); panic("out of memory. Compulsory panic_on_oom is selected.\n"); + } /* * Check if there were limitations on the allocation (only relevant for @@ -626,8 +632,10 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order) break; case CONSTRAINT_NONE: - if (sysctl_panic_on_oom) + if (sysctl_panic_on_oom) { + dump_header(gfp_mask, order, NULL); panic("out of memory. panic_on_oom is selected\n"); + } /* Fall-through */ case CONSTRAINT_CPUSET: __out_of_memory(gfp_mask, order); -- 2.39.5