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 <[email protected]> --- kernel/rcu/rcutorture.c | 6 ++++++ kernel/sched/core.c | 1 + 2 files changed, 7 insertions(+) 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) -- 2.5.2
