Summary:
- During repeating ostest with sabre-6quad:smp (QEMU),
I noticed that pthread_rwlock_test sometimes stops
- Finally, I found that nxtask_exit() released a critical
section too early before context switching which resulted in
selecting inappropriate TCB
- This commit fixes this issue by moving nxsched_resume_scheduler()
from nxtask_exit() to up_exit() and also removing
spin_setbit() and spin_clrbit() from nxtask_exit()
because the caller holds a critical section
- To be consistent with non-SMP cases, the above changes
were done for all CPU architectures
Impact:
- This commit affects all CPU architectures regardless of SMP
Testing:
- Tested with ostest with the following configs
- sabre-6quad:smp (QEMU, dev board), sabre-6quad:nsh (QEMU)
- spresense:wifi_smp
- sim:smp, sim:ostest
- maix-bit:smp (QEMU)
- esp32-devkitc:smp (QEMU)
- lc823450-xgevk:rndis
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Summary:
- This commit fixes global IRQ control logic
- In previous implementation, g_cpu_irqset for a remote CPU was
set in sched_add_readytorun(), sched_remove_readytorun() and
up_schedule_sigaction()
- In this implementation, they are removed.
- Instead, in the pause handler, call enter_critical_setion()
which will call up_cpu_paused() then acquire g_cpu_irqlock
- So if a new task with irqcount > 1 restarts on the remote CPU,
the CPU will only hold a critical section. Thus, the issue such as
'POSSIBLE FOR TWO CPUs TO HOLD A CRITICAL SECTION' could be resolved.
- Fix nxsched_resume_scheduler() so that it does not call spin_clrbit()
if a CPU does not hold a g_cpu_irqset
- Fix nxtask_exit() so that it acquires g_cpu_irqlock
- Update TODO
Impact:
- All SMP implementations
Testing:
- Tested with smp, ostest with the following configurations
- Tested with spresense:wifi_smp (NCPUS=2,4)
- Tested with sabre-6quad:smp (QEMU, dev board)
- Tested with maix-bit:smp (QEMU)
- Tested with esp32-core:smp (QEMU)
- Tested with lc823450-xgevk:rndis
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Summary:
- Apply the same logic added to cxd56_cpupause.c
Impact:
- SMP only
Testing:
- Tested with maix-bit:smp (QEMU)
- Run smp and ostest
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
So that it matches what the toolchain expects.
spacetanuki% riscv64-unknown-elf-gcc --version
riscv64-unknown-elf-gcc (SiFive GCC 8.3.0-2019.08.0) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
spacetanuki% riscv64-unknown-elf-gcc -dM -E - < /dev/null | grep UINT64_TYPE
#define __UINT64_TYPE__ long unsigned int
spacetanuki%
Summary:
- Apply the same fix for Arm SMP
Impact:
- Affects SMP only
Testing:
- Tested with maix-bit:smp (qemu)
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
When executing an MRET instruction, MIE is set to MPIE.
In order to branch to up_sigdeliver() with interrupts disabled,
we need to change MPIE, not MIE.
When executing an MRET instruction, MIE is set to MPIE.
In order to branch to up_sigdeliver() with interrupts disabled,
we need to change MPIE, not MIE.
