This PR is a modification that optimizes priority inheritance
for only one holder. After the above modifications are completed,
the mutex lock->unlock process that supports priority inheritance
can be optimized by 200 cycles.
Before modify: 2000 cycle
After modify: 1742 cycle
Signed-off-by: zhangyuan21 <zhangyuan21@xiaomi.com>
- The code will detect an error condition described in
https://cwiki.apache.org/confluence/display/NUTTX/Signaling+Semaphores+and+Priority+Inheritance
- The kernel will go to PANIC if semaphore holder can't be allocated even
if CONFIG_DEBUG_ASSERTIONS is disabled
- Clean-up code that handled posing of semaphore with priority inheritance
enabled from the interrupt context (remove nxsem_restore_baseprio_irq())
Assert in nxsem_post if:
- Priority inheritance is enabled on a semaphore
- A thread that does not hold the semaphore attempts to post it
This will detect an error condition described in https://cwiki.apache.org/confluence/display/NUTTX/Signaling+Semaphores+and+Priority+Inheritance
None. The debug instrumentation is only enabled if CONFIG_DEBUG_ASSERTIONS is enabled.
Use sim:ostest. Verify that no assertions occur.
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>
1. Internal scheduler functions should begin with nxsched_, not sched_
2. Follow the consistent naming patter of https://cwiki.apache.org/confluence/display/NUTTX/Naming+of+OS+Internal+Functions
# clock_systimer -> clock_systime_tick
# clock_systimespec -> clock_systime_timespec
sched_oneshot_extclk -> nxsched_oneshot_extclk
sched_period_extclk -> nxsched_period_extclk
# nxsem_setprotocol -> nxsem_set_protocol
# nxsem_getprotocol -> nxsem_get_protocol
# nxsem_getvalue -> nxsem_get_value
nxsem_initholders -> nxsem_initialize_holders
nxsem_addholder -> nxsem_add_holder
nxsem_addholder_tcb -> nxsem_add_holder_tcb
nxsem_boostpriority -> nxsem_boost_priority
nxsem_releaseholder -> nxsem_release_holder
nxsem_restorebaseprio -> nxsem_restore_baseprio
Some planned name changed were skipped for now because they effect too many files (and would require many hours of coding style fixups).
There is a DEBUGPANIC in some logic. This happens if a a task exists at certain points with priority inheritance enabled. This event was not expected in the original design (although logic was provided to support it). Since, apparently, it does happen, the DEBUGPANIC must be removed.
Noted by Brennan Ashton.
* Simplify EINTR/ECANCEL error handling
1. Add semaphore uninterruptible wait function
2 .Replace semaphore wait loop with a single uninterruptible wait
3. Replace all sem_xxx to nxsem_xxx
* Unify the void cast usage
1. Remove void cast for function because many place ignore the returned value witout cast
2. Replace void cast for variable with UNUSED macro
libs/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
syscall/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
wireless/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
Documentation/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
include/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
drivers/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
sched/: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
configs: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/xtensa: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/z80: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/x86: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/renesas and arch/risc-v: Remove references to CONFIG_DISABLE_SIGNALS. Signals can no longer be disabled.
arch/or1k: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/misoc: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/mips: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/avr: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
arch/arm: Remove all references to CONFIG_DISABLE_SIGNALS. Signals are always enabled.
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().
sched/mqueue: Rename all private static functions for use the nxmq_ vs. mq_ naming.
sched/mqueue: Rename all OS internal functions declared in sched/mqueue/mqueue.h to begin with nxmq_ vs. mq_. The mq_ prefix is reserved for standard application interfaces.
This commit backs out most of commit b4747286b1. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point.
In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable.
In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable.
sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
in the case of CONFIG_SEM_PREALLOCHOLDERS=0
The call to sem_restorebaseprio_task context switches in the
sem_foreachholder(sem, sem_restoreholderprioB, stcb); call
prior to releasing the holder. So the running task is left
as a holder as is the started task. Leaving both slots filled
Thus failing to perforem the boost/or restoration on the
correct tcb.
This PR fixes this by releasing the running task slot prior
to reprioritization that can lead to the context switch.
To faclitate this, the interface to sem_restorebaseprio
needed to take the tcb from the holder prior to the
holder being freed. In the failure case where sched_verifytcb
fails it added the overhead of looking up the holder.
There is also the adfitinal thunking on the foreach to
get from holer to holder->tcb.
An alternate approach could be to leve the interface the same
and allocate a holder on the stack of sem_restoreholderprioB
copy the sem's holder to it, free it as is done in this pr
and and then pass that address sem_restoreholderprio as the
holder. It could then get the holder's tcb but we would
keep the same sem_findholder in sched_verifytcb.
