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>
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>
Summary:
- This commit introduces SP_WFE() and SP_SEV() to be used for spinlock
- Also, use wfe/sev instructions for ARMV7-A to reduce power consumption
Impact:
- ARMV7-a SMP only
Testing:
- sabre-6quad:smp (QEMU, dev board)
- maix-bit:smp, esp32-devkitc:smp, spresense:smp sim:smp (compile only)
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
libs/libc/pthread/pthread_spinlock.c: Resolve several TODO issues by accessing up_testset() via the boardctl() interface rather than attempting to call it directly.
configs/boardctl.c, include/sys/boardctl.h: Add access to architecture-specific up_testset() via boardctl().
arch/Kconfig's, sched/Kconfig, and include/nuttx/spinlock.h: Spinlocks are not available unless the architecture supports the up_testset() operation.
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>
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>
This commit corrects this. This is matching logic in sched_addreadytorun to avoid starting new tasks within the critical section (unless the CPU is the holder of the lock). The holder of the IRQ lock must be permitted to do whatever it needs to do.
