1. remove up_interrupt_context() check, which should be safe in interrupt context
2. remove sem instance check will be handle in nxsem_trywait()
Signed-off-by: chao an <anchao@lixiang.com>
Otherwise the free holder list will leak, causing either a crash due to
holder->htcb = NULL, or the free holder list becomes (erroneously) empty
even though most of the holder entries are free.
The holder list can be modified via interrupt so using addrenv_select is
not safe. Access the semaphore by mapping it into kernel virtual memory
instead.
The temporary mappings via addrenv_select() and addrenv_restore() simply
do not work from interrupt, so remove its usage and replace with kmap
which is safe.
Add sem_wait fast operations, use atomic to ensure
atomicity of semcount operations, and do not depend
on critical section.
Test with robot:
before modify:
nxmutex_lock cost: 78 ns
nxmutex_unlock cost: 82 ns
after modify:
nxmutex_lock cost: 28 ns
nxmutex_unlock cost: 14 ns
Signed-off-by: zhangyuan29 <zhangyuan29@xiaomi.com>
This reverts commit befe29801f.
Because a few regressions have been reported and
it likely will take some time to fix them:
* for some configurations, semaphore can be used on the special
memory region, where atomic access is not available.
cf. https://github.com/apache/nuttx/pull/14625
* include/nuttx/lib/stdatomic.h is not compatible with
the C11 semantics, which the change in question relies on.
cf. https://github.com/apache/nuttx/pull/14755
Move CONFIG_SEM_PREALLOCHOLDERS to include/semaphore.h to avoid undefined issues from occurring in other places as well.
Signed-off-by: cuiziwei <cuiziwei@xiaomi.com>
Add sem_wait fast operations, use atomic to ensure
atomicity of semcount operations, and do not depend
on critical section.
Test with robot:
before modify:
nxmutex_lock cost: 78 ns
nxmutex_unlock cost: 82 ns
after modify:
nxmutex_lock cost: 28 ns
nxmutex_unlock cost: 14 ns
Signed-off-by: zhangyuan29 <zhangyuan29@xiaomi.com>
set CONFIG_PRIORITY_INHERITANCE=y
set CONFIG_SEM_PREALLOCHOLDERS=0 or CONFIG_SEM_PREALLOCHOLDERS=8
#24 0x4dcab71 in __assert assert/lib_assert.c:37
#25 0x4d6b0e9 in nxsem_destroyholder semaphore/sem_holder.c:602
#26 0x4d80cf7 in nxsem_destroy semaphore/sem_destroy.c:80
#27 0x4d80db9 in sem_destroy semaphore/sem_destroy.c:120
#28 0x4dcb077 in nxmutex_destroy misc/lib_mutex.c:122
#29 0x4dc6611 in pipecommon_freedev pipes/pipe_common.c:117
#30 0x4dc7fdc in pipecommon_close pipes/pipe_common.c:397
#31 0x4ed4f6d in file_close vfs/fs_close.c:78
#32 0x6a91133 in local_free local/local_conn.c:184
#33 0x6a92a9c in local_release local/local_release.c:129
#34 0x6a91d1a in local_subref local/local_conn.c:271
#35 0x6a75767 in local_close local/local_sockif.c:797
#36 0x4e978f6 in psock_close socket/net_close.c:102
#37 0x4eed1b9 in sock_file_close socket/socket.c:115
#38 0x4ed4f6d in file_close vfs/fs_close.c:78
#39 0x4ed1459 in nx_close_from_tcb inode/fs_files.c:754
#40 0x4ed1501 in nx_close inode/fs_files.c:781
#41 0x4ed154a in close inode/fs_files.c:819
#42 0x6bcb9ce in property_get kvdb/client.c:307
#43 0x6bcd465 in property_get_int32 kvdb/common.c:270
#44 0x5106c9a in tz_offset_restore app/miwear_bluetooth.c:745
#45 0x510893f in miwear_bluetooth_main app/miwear_bluetooth.c:1033
#46 0x4dcf5c8 in nxtask_startup sched/task_startup.c:70
#47 0x4d70873 in nxtask_start task/task_start.c:134
#48 0x4e04a07 in pre_start sim/sim_initialstate.c:52
Signed-off-by: ligd <liguiding1@xiaomi.com>
set CONFIG_PRIORITY_INHERITANCE=y
set CONFIG_SEM_PREALLOCHOLDERS=0
semaphore/sem_holder.c:320:34: runtime error: member access within null pointer of type 'struct tcb_s'
#0 0xd8b540 in nxsem_boostholderprio semaphore/sem_holder.c:320
#1 0xd8c1cf in nxsem_boost_priority semaphore/sem_holder.c:703
#2 0xda5dfa in nxsem_wait semaphore/sem_wait.c:145
#3 0xda61d9 in nxsem_wait_uninterruptible semaphore/sem_wait.c:248
#4 0x12f2477 in media_service_thread0 /home/ligd/platform/dev/apps/examples/hello/hello_main.c:44
#5 0x1204154 in pthread_startup pthread/pthread_create.c:59
#6 0x1cd906f in pthread_start pthread/pthread_create.c:139
#7 0xe72fcb in pre_start sim/sim_initialstate.c:52
Signed-off-by: ligd <liguiding1@xiaomi.com>
If the write lock is already held by oneself and sine the write
lock can be recursively held, so, this operation can be converted to a write
lock to avoid deadlock.
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
nxsem_tickwait correctly sleeps more than 1 tick. But nxsem_tickwait_uninterruptible
may wake up to a signal (with -EINTR), in which case the tick + 1 must also
be taken into account. Otherwise the nxsem_tickwait_uninterruptible may
wake up 1 tick too early.
Also fix the nxsem_tickwait to return with -ETIMEDOUT if called with delay 0.
This is similar to e.g. posix sem_timedwait.
Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
reason:
1In the scenario of active waiting, context switching is inevitable, and we can eliminate redundant judgments.
code size
before
hujun5@hujun5-OptiPlex-7070:~/downloads1/vela_sim/nuttx$ size nuttx
text data bss dec hex filename
262848 49985 63893 376726 5bf96 nuttx
after
hujun5@hujun5-OptiPlex-7070:~/downloads1/vela_sim/nuttx$ size nuttx
text data bss dec hex filename
263324 49985 63893 377202 5c172 nuttx
reduce code size by -476
Configuring NuttX and compile:
$ ./tools/configure.sh -l qemu-armv8a:nsh_smp
$ make
Running with qemu
$ qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic \
-machine virt,virtualization=on,gic-version=3 \
-net none -chardev stdio,id=con,mux=on -serial chardev:con \
-mon chardev=con,mode=readline -kernel ./nuttx
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
we can use g_cpu_lockset to determine whether we are currently in the scheduling lock,
and all accesses and modifications to g_cpu_lockset, g_cpu_irqlock, g_cpu_irqset
are in the critical section, so we can directly operate on it.
test:
We can use qemu for testing.
compiling
make distclean -j20; ./tools/configure.sh -l qemu-armv8a:nsh_smp ;make -j20
running
qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic -machine virt,virtualization=on,gic-version=3 -net none -chardev stdio,id=con,mux=on -serial chardev:con -mon chardev=con,mode=readline -kernel ./nuttx
Signed-off-by: hujun5 <hujun5@xiaomi.com>
The overhead of spinlok is less than mutext (mutex need to call
enter_critical section.)
After this patch, `down_write_trylock` and `down_read_trylock` can be
use in interrupt context.
The instruction is protected with mutex only one instruction so using
spinlock is better.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
A new locking mechanism: read/write locks
When there is a writer it is not possible to put on a read lock or a write lock; when there is a reader it is possible to reenter the read lock but not the write lock.
Writers are exclusive locks, readers are shared locks.
At the same time through the waiter count to determine whether there is currently a blocked task, if there is then in the unlock time to wake up all the waiter, through the priority of the competition to complete the blocked lock execution.
For example:
When we have a reader blocking two waiter writers, when the reader is unlocked it wakes up both writers. The writer with higher priority wakes up and checks for a successful condition and locks the lock, the second writer wakes up and fails to check for a condition and continues to block the lock.
Signed-off-by: chenrun1 <chenrun1@xiaomi.com>
This moves all the public POSIX semaphore functions into libc and with
this most of the user-space logic is also moved; namely cancel point and
errno handling.
This also removes the need for the _SEM_XX macros used to differentiate
which API is used per user-/kernel mode. Such macros are henceforth
unnecessary.
If the semaphore is shared, the holder has put its own mmapped address
to pholder->sem. This means we must switch to the holder's address
environment when going through the held semaphores list.
A better option would be to get the kernel mapped address for the
semaphore's physical page, but that mechanism is not functional yet.
This fixes a full system crash when CONFIG_PRIORITY_INHERITANCE=y and
CONFIG_BUILD_KERNEL=y and user makes shared semaphore via:
int semfd = shm_open("sem", O_CREAT | O_RDWR, 0666);
sem_t *sem = mmap(0, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_SHARED, semfd, 0);
This path just for modify Mac sim-02 issue.
The compiler require the firt paramter of atomic_compare_exchange_strong
is atomic type and second parameter is int type.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
spinlock.c:
Implement read write spinlock.
Readers can take lock simultaneously but only one writer can take lock.
irq_spinlock.c:
Align g_irq_spin_count.
If the lock is NULL, the caller will get global lock (e.g. g_irq_spin) and spin_lock_irqsave() support nest on the same CPU.
If the CPU can write lock, it can call write_lock_irqsave() again (e.g. support nest).
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
Co-authored-by: David Sidrane <David.Sidrane@Nscdg.com>
test config: ./tools/configure.sh -l qemu-armv8a:nsh_smp
Pass ostest
No matter big-endian or little-endian, ticket spinlock only check the
next and the owner is equal or not.
If they are equal, it means there is a task hold the lock or lock is
free.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
Co-authored-by: Xiang Xiao <xiaoxiang781216@gmail.com>
1. Update all CMakeLists.txt to adapt to new layout
2. Fix cmake build break
3. Update all new file license
4. Fully compatible with current compilation environment(use configure.sh or cmake as you choose)
------------------
How to test
From within nuttx/. Configure:
cmake -B build -DBOARD_CONFIG=sim/nsh -GNinja
cmake -B build -DBOARD_CONFIG=sim:nsh -GNinja
cmake -B build -DBOARD_CONFIG=sabre-6quad/smp -GNinja
cmake -B build -DBOARD_CONFIG=lm3s6965-ek/qemu-flat -GNinja
(or full path in custom board) :
cmake -B build -DBOARD_CONFIG=$PWD/boards/sim/sim/sim/configs/nsh -GNinja
This uses ninja generator (install with sudo apt install ninja-build). To build:
$ cmake --build build
menuconfig:
$ cmake --build build -t menuconfig
--------------------------
2. cmake/build: reformat the cmake style by cmake-format
https://github.com/cheshirekow/cmake_format
$ pip install cmakelang
$ for i in `find -name CMakeLists.txt`;do cmake-format $i -o $i;done
$ for i in `find -name *\.cmake`;do cmake-format $i -o $i;done
Co-authored-by: Matias N <matias@protobits.dev>
Signed-off-by: chao an <anchao@xiaomi.com>
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>
Store the old environment in a local context so another temporary address
environment can be selected. This can happen especially when a process
is being loaded (the new process's mappings are temporarily instantiated)
and and interrupt occurs.
- 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.
sem_t is user memory and the correct mappings are needed to perform
the semaphore wait interruption.
Otherwise either a page fault, or access to the WRONG address environment
happens.
NuttX kernel should not use the syscall functions, especially after
enabling CONFIG_SCHED_INSTRUMENTATION_SYSCALL, all system functions
will be traced to backend, which will impact system performance.
Signed-off-by: chao an <anchao@xiaomi.com>
