It seems to have nothing to do with the race condition, and since the rtcb is
this_task, it will only be modified by one CPU.<br/><br/>As for why your
modification can solve the problem, I haven't figured it out yet. Can you
further analyze the reasons for the failure to boot?
At 2025-04-22 13:25:13, "Serg Podtynnyi" <s...@podtynnyi.com.INVALID> wrote:
>Hi All, Gregory, Sebastien,
>
>I'm porting NuttX on rp2350(pico2 board inside ClockWork PicoCalc) and
>having trouble getting SMP (2-core) config running
>
>without patching the sched lock/unlock routines.
>
>I am looking at the commit
>https://github.com/apache/nuttx/commit/914ae532e68bf4ca75c758d6f541a1d2fcdce8c3
>
>and reverting it helps to boot the system.
>
>This the the patch to make it work for me, I updated the current
>lock/unlock by moving the enter_critical_section above the access to
>rtcb->lockcount
>
>Do you think it could be the case of a race condition with rtcb->lockcount ?
>
>PS
>
>It's almost 11 years since I last touched NuttX - it's a please to work
>with it again.
>
>
> From 86fa0a65fdd37804154faf3db52e2826281cdfbd Mon Sep 17 00:00:00 2001
>From: Serg Podtynnyi <s...@podtynnyi.com>
>Date: Tue, 22 Apr 2025 11:37:48 +0700
>Subject: sched: update lock/unlock critical section entry
>
>Level up enter_critical_section in sched lock/unlock to cover
>rtcb->lockcount access
>
>Signed-off-by: Serg Podtynnyi <s...@podtynnyi.com>
>---
> sched/sched/sched_lock.c | 4 ++--
> sched/sched/sched_unlock.c | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
>diff --git a/sched/sched/sched_lock.c b/sched/sched/sched_lock.c
>index d8f75e7c90..9cc8da3df4 100644
>--- a/sched/sched/sched_lock.c
>+++ b/sched/sched/sched_lock.c
>@@ -82,18 +82,18 @@ void sched_lock(void)
> * operations on this thread (on any CPU)
> */
>
>+ irqstate_t flags = enter_critical_section_wo_note();
> if (rtcb != NULL && rtcb->lockcount++ == 0)
> {
> #if (CONFIG_SCHED_CRITMONITOR_MAXTIME_PREEMPTION >= 0) || \
> defined(CONFIG_SCHED_INSTRUMENTATION_PREEMPTION)
>- irqstate_t flags = enter_critical_section_wo_note();
>
> /* Note that we have pre-emption locked */
>
> nxsched_critmon_preemption(rtcb, true, return_address(0));
> sched_note_preemption(rtcb, true);
>- leave_critical_section_wo_note(flags);
> #endif
> }
>+ leave_critical_section_wo_note(flags);
> }
> }
>diff --git a/sched/sched/sched_unlock.c b/sched/sched/sched_unlock.c
>index 4c7d681454..d21e007587 100644
>--- a/sched/sched/sched_unlock.c
>+++ b/sched/sched/sched_unlock.c
>@@ -69,9 +69,9 @@ void sched_unlock(void)
> * then pre-emption has been re-enabled.
> */
>
>+ irqstate_t flags = enter_critical_section_wo_note();
> if (rtcb != NULL && --rtcb->lockcount == 0)
> {
>- irqstate_t flags = enter_critical_section_wo_note();
>
> /* Note that we no longer have pre-emption disabled. */
>
>@@ -162,7 +162,7 @@ void sched_unlock(void)
> }
> #endif
>
>- leave_critical_section_wo_note(flags);
> }
>+ leave_critical_section_wo_note(flags);
> }
> }
>--
>2.49.0
>
>
>--
>Serg Podtynnyi
>
