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The following commit(s) were added to refs/heads/master by this push:
new dc6ddd8d4d7 sched: Fix scheduler CPU selection and ready-to-run list
management
dc6ddd8d4d7 is described below
commit dc6ddd8d4d7ef1c9bd49c79b3802d4867655d85b
Author: hujun5 <[email protected]>
AuthorDate: Wed Jan 28 20:00:20 2026 +0800
sched: Fix scheduler CPU selection and ready-to-run list management
Fix critical issues in SMP scheduler: correct CPU selection logic by
removing redundant lock check and prioritizing eligible CPUs, simplify
ready-to-run list addition by removing unnecessary condition check and
early validation, and relocate switch_running() call for proper cleanup
sequencing in remove_self() operation.
Signed-off-by: hujun5 <[email protected]>
---
sched/sched/sched.h | 6 +++---
sched/sched/sched_addreadytorun.c | 17 ++++++++---------
sched/sched/sched_process_delivered.c | 2 +-
sched/sched/sched_removereadytorun.c | 3 ++-
4 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/sched/sched/sched.h b/sched/sched/sched.h
index db20164b90e..cd75865003e 100644
--- a/sched/sched/sched.h
+++ b/sched/sched/sched.h
@@ -577,7 +577,7 @@ static inline_function int nxsched_select_cpu(cpu_set_t
affinity)
int i;
minprio = SCHED_PRIORITY_MAX;
- cpu = CONFIG_SMP_NCPUS;
+ cpu = 0xff;
for (i = 0; i < CONFIG_SMP_NCPUS; i++)
{
@@ -600,8 +600,7 @@ static inline_function int nxsched_select_cpu(cpu_set_t
affinity)
DEBUGASSERT(rtcb->sched_priority == 0);
return i;
}
- else if (rtcb->sched_priority <= minprio &&
- !nxsched_islocked_tcb(rtcb))
+ else if (rtcb->sched_priority <= minprio)
{
DEBUGASSERT(rtcb->sched_priority > 0);
minprio = rtcb->sched_priority;
@@ -610,6 +609,7 @@ static inline_function int nxsched_select_cpu(cpu_set_t
affinity)
}
}
+ DEBUGASSERT(cpu != 0xff);
return cpu;
}
# endif
diff --git a/sched/sched/sched_addreadytorun.c
b/sched/sched/sched_addreadytorun.c
index d4bc4e66d87..2724a1bd5ac 100644
--- a/sched/sched/sched_addreadytorun.c
+++ b/sched/sched/sched_addreadytorun.c
@@ -163,7 +163,7 @@ bool nxsched_switch_running(int cpu, bool switch_equal)
return false;
}
- if (switch_equal)
+ if (switch_equal && sched_priority > 0)
{
sched_priority--;
}
@@ -255,6 +255,7 @@ bool nxsched_add_readytorun(FAR struct tcb_s *btcb)
bool doswitch = false;
int target_cpu = btcb->flags & TCB_FLAG_CPU_LOCKED ? btcb->cpu :
nxsched_select_cpu(btcb->affinity);
+ FAR struct tcb_s *tcb = current_task(target_cpu);
/* Add the btcb to the ready to run list, and try to run it on the target
* CPU
@@ -263,15 +264,13 @@ bool nxsched_add_readytorun(FAR struct tcb_s *btcb)
btcb->task_state = TSTATE_TASK_READYTORUN;
nxsched_add_prioritized(btcb, list_readytorun());
- if (target_cpu < CONFIG_SMP_NCPUS)
- {
- FAR struct tcb_s *tcb = current_task(target_cpu);
+ /* In some cases, such as setaffinity, cpu need to be used. */
- if (tcb->sched_priority < btcb->sched_priority)
- {
- doswitch = nxsched_deliver_task(this_cpu(), target_cpu,
- SWITCH_HIGHER);
- }
+ btcb->cpu = target_cpu;
+ if (tcb->sched_priority < btcb->sched_priority)
+ {
+ doswitch = nxsched_deliver_task(this_cpu(), target_cpu,
+ SWITCH_HIGHER);
}
return doswitch;
diff --git a/sched/sched/sched_process_delivered.c
b/sched/sched/sched_process_delivered.c
index 663161de754..36effcd028d 100644
--- a/sched/sched/sched_process_delivered.c
+++ b/sched/sched/sched_process_delivered.c
@@ -105,7 +105,7 @@ void nxsched_process_delivered(int cpu)
{
int target_cpu = tcb->flags & TCB_FLAG_CPU_LOCKED ?
tcb->cpu : nxsched_select_cpu(tcb->affinity);
- if (target_cpu < CONFIG_SMP_NCPUS && target_cpu != cpu &&
+ if (target_cpu != cpu &&
current_task(target_cpu)->sched_priority < tcb->sched_priority)
{
nxsched_deliver_task(cpu, target_cpu, priority);
diff --git a/sched/sched/sched_removereadytorun.c
b/sched/sched/sched_removereadytorun.c
index 0166c443fe6..88b11263a44 100644
--- a/sched/sched/sched_removereadytorun.c
+++ b/sched/sched/sched_removereadytorun.c
@@ -162,12 +162,13 @@ static void nxsched_remove_running(FAR struct tcb_s *tcb)
nxttcb->task_state = TSTATE_TASK_RUNNING;
g_assignedtasks[cpu] = nxttcb;
up_update_task(nxttcb);
+
+ nxsched_switch_running(tcb->cpu, false);
}
void nxsched_remove_self(FAR struct tcb_s *tcb)
{
nxsched_remove_running(tcb);
- nxsched_switch_running(tcb->cpu, false);
}
bool nxsched_remove_readytorun(FAR struct tcb_s *tcb)
