State of problem:
- Some drivers that do not support write operations (does not
have write handler or ioctl do not perform any write actions)
are registered with write permissions
- Some drivers that do not support read operation (does not
have read handler or ioctl do not perform any read actions)
are registered with read permissions
- Some drivers are registered with execute permissions
Solution:
- Iterate code where register_driver() is used and change 'mode'
parameter to reflect the actual read/write operations executed
by a driver
- Remove execute permissions from 'mode' parameter
Signed-off-by: Petro Karashchenko <petro.karashchenko@gmail.com>
1. The task which called nxsem_release_holder may not be a holder of the semaphore,
counts of the holder would not be decreamented.
This commit try to resolve the problem if there is only one holder.
2. Avoid counts overflow.
Signed-off-by: Zeng Zhaoxiu <walker.zeng@transtekcorp.com>
Add a list in TCB to track all semphores the task held, so we
can release all holders when exit, so nxsched_verify_tcb
is unnecessary.
Signed-off-by: Zeng Zhaoxiu <walker.zeng@transtekcorp.com>
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.
