June 12, 2026 at 3:58 AM, "Paul E. McKenney" <[email protected] mailto:[email protected]?to=%22Paul%20E.%20McKenney%22%20%3Cpaulmck%40kernel.org%3E > wrote:
> > On Thu, Jun 11, 2026 at 03:32:01PM +0800, Kunwu Chan wrote: > > > > > From: Kunwu Chan <[email protected]> > > > > RCU stall warnings currently print task states as raw hexadecimal > > values (e.g., ->state=0x402), forcing developers to manually decode > > them from memory. > > > > Replace these raw hex values with the compact, single-letter symbols > > already established by sched_show_task(): > > > > ->state=0x402 becomes ->state=I (TASK_IDLE) > > ->state=0x0 becomes ->state=R (TASK_RUNNING) > > ->state=0x2 becomes ->state=D (TASK_UNINTERRUPTIBLE) > > > > Convert five print sites across tree_stall.h, rcutorture.c, and > > hazptrtorture.c to use task_state_to_char() instead of the raw > > ->__state value. > > > > Suggested-by: Zqiang <[email protected]> > > Co-developed-by: Wang Lian <[email protected]> > > Signed-off-by: Wang Lian <[email protected]> > > Signed-off-by: Kunwu Chan <[email protected]> > > > Nice! > > But could you please split this into three commits, one for each file? > That makes it easier to create branches to send to Linus. Especially > since hazptrtorture.c will likely be in a different pull request. ;-) > > Thanx, Paul > Sure, I'll split it into one commit per file. Makes sense, especially for the hazptr one. ;-) Thanks! > > > > --- > > Based on: linux-rcu repo (dev branch) > > URL: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > base-commit: 85bf11e84 ("smp: Make CSD lock acquisition atomic for debug > > mode") > > --- > > kernel/rcu/hazptrtorture.c | 4 ++-- > > kernel/rcu/rcutorture.c | 4 ++-- > > kernel/rcu/tree_stall.h | 12 ++++++------ > > 3 files changed, 10 insertions(+), 10 deletions(-) > > > > diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c > > index 0da0a4606..19ea479c9 100644 > > --- a/kernel/rcu/hazptrtorture.c > > +++ b/kernel/rcu/hazptrtorture.c > > @@ -497,10 +497,10 @@ hazptr_torture_stats_print(void) > > unsigned long __maybe_unused gp_seq = 0; > > > > wtp = READ_ONCE(writer_task); > > - pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", > > + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %c cpu %d\n", > > hazptr_torture_writer_state_getname(), > > hazptr_torture_writer_state, gp_seq, flags, > > - wtp == NULL ? ~0U : wtp->__state, > > + wtp == NULL ? '?' : task_state_to_char(wtp), > > wtp == NULL ? -1 : (int)task_cpu(wtp)); > > if (!splatted && wtp) { > > sched_show_task(wtp); > > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c > > index fcb421ced..4d4ebeeea 100644 > > --- a/kernel/rcu/rcutorture.c > > +++ b/kernel/rcu/rcutorture.c > > @@ -3074,10 +3074,10 @@ rcu_torture_stats_print(void) > > if (cur_ops->get_gp_data) > > cur_ops->get_gp_data(&flags, &gp_seq); > > wtp = READ_ONCE(writer_task); > > - pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n", > > + pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %c cpu %d\n", > > rcu_torture_writer_state_getname(), > > rcu_torture_writer_state, gp_seq, flags, > > - wtp == NULL ? ~0U : wtp->__state, > > + wtp == NULL ? '?' : task_state_to_char(wtp), > > wtp == NULL ? -1 : (int)task_cpu(wtp)); > > if (!splatted && wtp) { > > sched_show_task(wtp); > > diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h > > index 317ef91b1..7ca434b08 100644 > > --- a/kernel/rcu/tree_stall.h > > +++ b/kernel/rcu/tree_stall.h > > @@ -596,13 +596,13 @@ static void rcu_check_gp_kthread_starvation(void) > > > > if (rcu_is_gp_kthread_starving(&j)) { > > cpu = gpk ? task_cpu(gpk) : -1; > > - pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x > > ->cpu=%d\n", > > + pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%c > > ->cpu=%d\n", > > rcu_state.name, j, > > (long)rcu_seq_current(&rcu_state.gp_seq), > > data_race(READ_ONCE(rcu_state.gp_flags)), > > gp_state_getname(rcu_state.gp_state), > > data_race(READ_ONCE(rcu_state.gp_state)), > > - gpk ? data_race(READ_ONCE(gpk->__state)) : ~0, cpu); > > + gpk ? task_state_to_char(gpk) : '?', cpu); > > if (gpk) { > > struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu); > > > > @@ -639,12 +639,12 @@ static void > > rcu_check_gp_kthread_expired_fqs_timer(void) > > time_after(jiffies, jiffies_fqs + RCU_STALL_MIGHT_MIN) && > > gpk && !READ_ONCE(gpk->on_rq)) { > > cpu = task_cpu(gpk); > > - pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x > > %s(%d) ->state=%#x\n", > > + pr_err("%s kthread timer wakeup didn't happen for %ld jiffies! g%ld f%#x > > %s(%d) ->state=%c\n", > > rcu_state.name, (jiffies - jiffies_fqs), > > (long)rcu_seq_current(&rcu_state.gp_seq), > > data_race(READ_ONCE(rcu_state.gp_flags)), // Diagnostic read > > gp_state_getname(RCU_GP_WAIT_FQS), RCU_GP_WAIT_FQS, > > - data_race(READ_ONCE(gpk->__state))); > > + task_state_to_char(gpk)); > > pr_err("\tPossible timer handling issue on cpu=%d timer-softirq=%u\n", > > cpu, kstat_softirqs_cpu(TIMER_SOFTIRQ, cpu)); > > } > > @@ -971,10 +971,10 @@ void show_rcu_gp_kthreads(void) > > jr = j - data_race(READ_ONCE(rcu_state.gp_req_activity)); > > js = j - data_race(READ_ONCE(rcu_state.gp_start)); > > jw = j - data_race(READ_ONCE(rcu_state.gp_wake_time)); > > - pr_info("%s: wait state: %s(%d) ->state: %#x ->rt_priority %u delta > > ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu > > ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags > > %#x\n", > > + pr_info("%s: wait state: %s(%d) ->state: %c ->rt_priority %u delta > > ->gp_start %lu ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu > > ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_max %lu ->gp_flags > > %#x\n", > > rcu_state.name, gp_state_getname(rcu_state.gp_state), > > data_race(READ_ONCE(rcu_state.gp_state)), > > - t ? data_race(READ_ONCE(t->__state)) : 0x1ffff, t ? t->rt_priority : > > 0xffU, > > + t ? task_state_to_char(t) : '?', t ? t->rt_priority : 0xffU, > > js, ja, jr, jw, (long)data_race(READ_ONCE(rcu_state.gp_wake_seq)), > > (long)data_race(READ_ONCE(rcu_state.gp_seq)), > > (long)data_race(READ_ONCE(rcu_get_root()->gp_seq_needed)), > > -- > > 2.43.0 > > >
