Fix signal handing for smp
* sched/signal: Remove SMP related logic in sig_dispatch.c
This change prevents from a deadlock in up_schedulesigaction.c
where inter-CPU signal handling is actually implemented.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* arch/arm/src/armv7-m: Fix signal handling for SMP
In previous implementation, signal handling for SMP was incorrect.
Thus, for example, if an inter-CPU signal happened an incorret tcb
was signaled and caused ASSERT().
This change fixes the issues and works for both inter-CPU signal
handling and signal handling on the same CPU.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
sched/: Convert legitimate uses of task_create() to nxtask_create(). Review handling of returned values from all uses of kthread_create() (as well as nxtask_create()).
graphics/: Review return values for all calls to kthread_start() because it no longer returns an errno.
drivers/: threads started by drivers should be kernel threads, not user tasks. Review return values for all calls to kthread_start() because it no longer returns an errno.
configs/: threads started by board bringup logic should be kernel threads, not user tasksi (part 2 of 2).
sched/task: Add nxtask_create(). Kthread_create() and nxtask_create() are internal OS functions and should not modify the errno variable. configs/: threads started by board bringup logic should be kernel threads, not user tasks.
The previous implementation of clearing global IRQ in sched_addreadytorun()
and sched_removereadytorun() was done too early. As a result, nxsem_post()
would have a chance to enter the critical section even nxsem_wait() is
still not in blocked state. This patch moves clearing global IRQ controls
from sched_addreadytorun() and sched_removereadytorun() to sched_resumescheduler()
to ensure that nxsem_post() can enter the critical section correctly.
For this change, sched_resumescheduler.c is always necessary for SMP configuration.
In addition, by this change, task_exit() had to be modified so that it calls
sched_resumescheduler() because it calls sched_removescheduler() inside the
function, otherwise it will cause a deadlock.
However, I encountered another DEBUGASSERT() in sched_cpu_select() during
HTTP streaming aging test on lc823450-xgevk. Actually sched_cpu_select()
accesses the g_assignedtasks which might be changed by another CPU. Similarly,
other tasklists might be modified simultaneously if both CPUs are executing
scheduling logic. To avoid this, I introduced tasklist protetion APIs.
With these changes, SMP kernel stability has been much improved.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
binfmt/, configs/, grahics/, libc/, mm/, net/, sched/: OS references to the errno variable should always use the set_errno(), get_errno() macros
arch/arm/src/stm32 and stm32f7: Architecture-specific code is not permitted to modify the errno variable. drivers/ and libc/: OS references to the errno variable should always use the set_errno(), get_errno() macros
sched/sched: Correct some build issues introduced by last set of changes.
sched/sched: Add new internal OS function nxsched_setaffinity() that is identical to sched_isetaffinity() except that it does not modify the errno value. All usage of sched_setaffinity() within the OS is replaced with nxsched_setaffinity().
sched/sched: Internal functions sched_reprioritize() and sched_setpriority() no longer movidify the errno value. Also renamed to nxsched_reprioritize() and sched_setpriority().
sched/sched: Add new internal OS function nxsched_getscheduler() that is identical to sched_getscheduler() except that it does not modify the errno value. All usage of sched_getscheduler() within the OS is replaced with nxsched_getscheduler().
sched/sched: Add new internal OS function nxsched_setparam() that is identical to sched_setparam() except that it does not modify the errno value. All usage of sched_setparam() within the OS is replaced with nxsched_setparam().
sched/sched: Add new internal OS function nxsched_getparam() that is identical to sched_getparam() except that it does not modify the errno value (actually, the previous value erroneously neglected to set the errno value to begin with, but this fixes both issues). All usage of sched_getparam() within the OS is replaced with nxsched_getparam().
These APIs are used in sched_note.c to protect instumentation data.
The deffrence between these APIs to exsiting spin_lock() and spin_unlock()
is that they do not perform insturumentation to avoid recursive call
when SCHED_INSTRUMENTATION_SPINLOCKS=y.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
If SMP=n or SMP=y && SPINLOCK_IRQ=n, this works in the same way as before.
If SMP=y && SPINLOCK_IRQ=y, performance will be improved.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
In ARM document regarding memory barrires, SP_DMB() must be issued
before changing a spinlock state to SP_UNLOCKED. However, we found
that SP_DSB() is also needed to ensure that spin_unlock() works
correctly for network streaming aging test.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
sched/sched: Remove DEBUGASSERT() in sched_mergepending()
Because this DEBUGASSERT() assumes that while loop executes only once.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
SMP: Introduce spin_lock_irqsave() and spin_unlock_irqrestore()
These APIs are simplified version of enter_critical_section() and
leave_critical_section() to protect data (e.g. registers) in SMP mode.
By using these APIs inside drivers, performace will be improved.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
