Add a comment briefly explaining why one timer tick is added to the watchdog delay. This has confused a lot of people and has resulted in numerous awkward discussions and ill-informed attempts to modify the code to remove that addition. Perhaps a rather lengthy comment will reduce that confusion and put an end to this thrashing.
should be removed by:
commit fca07be1df
Author: Gregory Nutt <gnutt@nuttx.org>
Date: Tue Oct 10 08:43:10 2017 -0600
Squashed commit of the following:
Change all calls to mq_send() and mq_timedsend() in the OS to calls to
nxmq_send() and nxmq_timedsend(), making appropriate changes for differences
in return values.
sched/mqueue: Add internal function nxmq_send() and nxmq_timedsend() that are
equivalent to mq_send() and mq_timedsend() except that they do not create
cancellation points and do to not modify the errno variable.
Signed-off-by: chao.an <anchao@xiaomi.com>
since the related code was removed by:
commit 4d5a964f29
Author: Jiuzhu Dong <dongjiuzhu1@xiaomi.com>
Date: Tue Feb 23 18:04:13 2021 +0800
net: unify socket into file descriptor
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Perf timer interface generally uses the hardware cycle counter
provided by the arch chip directly(such as DWT_CYCCNT(cortex-m)),
CYCCNT is a free running counter and counting upwards.
It wraps around to 0 on overflow.
Signed-off-by: chao.an <anchao@xiaomi.com>
For example, task is blocked by nxsem_wait(sem1), use nxsem_wait(sem2)
in signal handler, and take sem2 successfully, after exit from signal
handler to task, nxsem_wait(sem1) returns OK, but the correct result
should be -EINTR.
Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
The BUG is as follow:
1. Suppose there are two ready tasks t1 and t2 have the same priority, and t1 is the running.
2. A new, higher priority task t0 (such as hpwork) is ready, then switch to t0.
3. After t0 is suspended, then switch to t1 and reset the t1's timeslice.
4. goto 2
The t2 will have no chance to run.
Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng@gmail.com>
1. If CONFIG_SCHED_INSTRUMENTATION_SWITCH is enabled, then these additional interfaces are expected:
sched_note_suspend
sched_note_resume
at the same time，If CONFIG_SMP is enabled，then expected：
sched_note_cpu_pause
sched_note_cpu_paused
sched_note_cpu_resume
sched_note_cpu_resumed
2. other board if enable SCHED_INSTRUMENTATION，SCHED_INSTRUMENTATION_SWITCH to defconfig.
There is a potential problem that can lead to deadlock at
condition wait, if the timeout of watchdog is a very small value
(1 tick ?), the timer interrupt will come before the nxsem_wait()
Revert "sched: pthread: Remove a redundant critical section in pthread_condclockwsait.c"
Revert "sched: semaphore: Remove a redundant critical section in nxsem_clockwait()"
Revert "sched: semaphore: Remove a redundant critical section in nxsem_tickwait()"
This reverts commit 7758f3dcb1.
This reverts commit 2976bb212e.
This reverts commit 65dec5d10a.
Signed-off-by: chao.an <anchao@xiaomi.com>
argv is allocated from stack and then belong to userspace,
so task_info_s is a best location to hold this information.
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Summary:
- This commit introduces a private spinlock in sig_action.c
Impact:
- None
Testing:
- Tested with spresense:wifi_smp and spresense:wifi
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
