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

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