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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-08-30 10:40:17 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-10-09 14:26:09 -0700 |
| commit | 0032f4e889764d22ccccb6a15742071d6f0d1f5a (patch) | |
| tree | 93b8ed1a0626d8d713d1587681c77dd9dda02342 /kernel | |
| parent | 2b1516e55f8416acfb48d5f43d41222d180fb5a3 (diff) | |
| download | lwn-0032f4e889764d22ccccb6a15742071d6f0d1f5a.tar.gz lwn-0032f4e889764d22ccccb6a15742071d6f0d1f5a.zip | |
rcutorture: Dump writer stack if stalled
Right now, rcutorture warns if an rcu_torture_writer() kthread stalls,
but this warning is not always all that helpful. This commit therefore
makes the first such warning include a stack dump.
This in turn requires that sched_show_task() be exported to GPL modules,
so this commit makes that change as well.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 6 | ||||
| -rw-r--r-- | kernel/sched/core.c | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 0273bc0a8586..362eb2f78b3c 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -51,6 +51,7 @@ #include <asm/byteorder.h> #include <linux/torture.h> #include <linux/vmalloc.h> +#include <linux/sched/debug.h> #include "rcu.h" @@ -1240,6 +1241,7 @@ rcu_torture_stats_print(void) long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; static unsigned long rtcv_snap = ULONG_MAX; + static bool splatted; struct task_struct *wtp; for_each_possible_cpu(cpu) { @@ -1325,6 +1327,10 @@ rcu_torture_stats_print(void) gpnum, completed, flags, wtp == NULL ? ~0UL : wtp->state, wtp == NULL ? -1 : (int)task_cpu(wtp)); + if (!splatted && wtp) { + sched_show_task(wtp); + splatted = true; + } show_rcu_gp_kthreads(); rcu_ftrace_dump(DUMP_ALL); } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d17c5da523a0..7ae0151dcc1d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5165,6 +5165,7 @@ void sched_show_task(struct task_struct *p) show_stack(p, NULL); put_task_stack(p); } +EXPORT_SYMBOL_GPL(sched_show_task); static inline bool state_filter_match(unsigned long state_filter, struct task_struct *p) |