This commit repartitions the logic by moving some of the changes from mm_sem.c into task_getpid.c. The logic is equivalent for the case of mm_trysemaphore(), but no has wider impact since it potentially affects all callers of getpid(). Hence, this change may also introduce some other issues that will need to be addressed.
This solution to the problem noted by EunBong Song results in major memory fragmentation and and out-of-memory conditions on the PX4 platform. On that platform the lower priority work queue is very low priority and essentially never runs when the system is busy. As a result, the systems gets slowly starved of memory until failures and bad behaviors begin to occur.
This is an addition patch coming later to result the original problem in a different way that does not have cause memory starvation.
This reverts commit 91aa26774b.
fs/procfs/fs_procfsproc: Extended the process ID ProcFS output to show per-thread maximum time for pre-emption disabled and maximum time within a critical section.
sched/sched/sched_critmonitor.c: Adds data collection logic in support of monitoring critical sections and pre-emption state.
1. Move exepath_*() related code to libc/misc
1. Rename exepath_ to envpath_
2. Rename BINFMT_EXEPATH to LIB_ENVPATH
libs/libc/modlib: Add pre module library symbol table support
many locations: Change occurences of open() followed by file_detach() to file_open(). Change most non-controversion calls to open() to nx_open().
fs/inode/fs_fileopen.c: Flesh out file_open() with some interim, placeholder logic.
fs/inode/fs_fileopen.c: Add a framework for a file_open() implementation (no real logic in place yet).
fs/vfs/fs_open.c: Add nx_open() which is the same as open() except that it does not create a cancellation point nor does it modify the errno variable.
sched/wqueue/kwork_notifier.c: Redesign some data structures. struct works_s must appear at the beginning of the notifier entry structure. That is because it contains the work queue indices. This solves a harfault issue.
net/tcp/tcp_netpoll.c: tcp_iob_work() needs to free the allocated argument when it is finished.
net/tcp/tcp_send_buffered.c: Extend psock_tcp_cansend() so that it also requires that at least on IOB is also avaialble.
mm/iob: iob_navail() was returning the number of free IOB chain queue entries, not the number of free IOBs. Completely misnamed.
net/tcp/tcp_netpoll.c: Add logic to receive notifications when IOBs are freed (Needs CONFIG_NET_TCP_WRITE_BUFFERS and CONFIG_IOB_NOTIFIER). At present, does nothing because the logic in in psock_tcp_cansend() does not check for the availability of IOBs. That will change.
TASK A TASK B
malloc()
mm_takesemaphore()
heap holder is set to TASK B
<--- preempt
...
task_exit()
Set to current task to
TASK B
Try to release tcb, and
stack memory
free()
mm_takesemaphore()
- Successfully obtain
semaphore because current
task and heap holder is
same.
Free memory....
Heap corrupt.
This change forces all de-allocations via sched_kfree() and sched_ufree()
to be delayed. Eliminating the immediate de-allocation prevents the
above problem with the the re-entrant semaphore because the deallocation
always occurs on the worker thread, never on TASK B.
There could be consequences in the timing of memory availability. We
will see.
Squashed commit of the following:
Fix up some final compile isses.
net/netdev: Convert the network down notification logic to use the new wqueue-based notification factility.
net/udp: Convert the UDP readahead notification logic to use the new wqueue-based notification factility.
net/tcp: Convert the TCP readahead notification logic to use the new wqueue-based notification factility.
mm/iob: Convert the IOB notification logic to use the new wqueue-based notification factility.
sched/wqueue: Signals are not good IPCs to support the target poll functionality for several reasons including the amount of data that can be passed with a signal and in the fact that in protected and kernel modes, user threads executing signal handlers in protected, kernel memory is problematic. Instead, convert the same logic to perform the notifications via function callback on the high priority work queue.
Squashed commit of the following:
mm/iob: The IOB available notifier is now just a wrapper around the common signal notifier.
sched/signal: Add a generic signal notification facility.
sched/signal/sig_evthread.c: More trivial naming changes.
sched/signal: Rename nxsig_notification() to nxsig_evthread() to make forthcoming naming additions more consistent.
Squashed commit of the following:
Add procfs support to show stopped tasks. Add nxsig_action() to solve a chicken and egg problem: We needed to use sigaction to set default actions, but sigaction() would refuse to set actions if the default actions could not be caught or ignored.
sched/signal: Add configuration option to selectively enabled/disable default signal actions for SIGSTOP/SIGSTP/SIGCONT and SIGKILL/SIGINT. Fix some compilation issues.
sched/sched: Okay.. I figured out a way to handle state changes that may occur while they were stopped. If a task/thread was already blocked when SIGSTOP/SIGSTP was received, it will restart in the running state. I will appear that to the task/thread that the blocked condition was interrupt by a signal and returns the EINTR error.
sched/group and sched/sched: Finish framework for continue/resume logic.
sched/signal: Roughing out basic structure to support task suspend/resume
drivers/serial/Kconfig: It is no longer necessary to restrict Ctrl-C handling to the FLAT build
sched/signal: Add a new configuration option to select signal default actions, separate handling of signal default actions from both task startup logic and from the serial TTY Ctrl-C logic. Add a signal set in the group structure to keep track of what signals have been set to the default action. In dispatching signals in PROTECTED or KERNEL mode, use this signal set to determine if the default signal handler is attached and dispatch the signal in kernel mode for the default actions.
drivers/serial: Add Ctrl-C/Ctrl-X support. This is an initial working implementation that still requires that several details be resolved.
sched/task/task_start.c: Add default signal action to SIGKILL.
sched/wqueue: Modify high priority work queue to support multiple threads.
sched/wqueue and libs/libc/wqueue: workqueues don't need set global data to zero since .bss is cleared automatically. Removing this unnecessary initialization also avoids the loss the work items queued before initialization.
include/nuttx/arch.h: Add prototype for an architecture-specific up_trigger_irq function
arch/, include/nuttx, sched/sched: Add the garbage collection hook so each architecture can do custom memory cleanup if necesary.
arch/Kconfig: Add configureation CONFIG_ARCH_GNU_NO_WEAKFUNCTIONS to suppress use of weak functions. Some gnu derived toolchains do not support weak symbols
Author: Xiang Xiao <xiaoxiang@xiaomi.com>
arch/arm/src/armv7-m: Implement SYSTICK timer driver
Author: anchao <anchao@pinecone.net>
configs/sim/loadable: Add loadable demo for arch sim
sched/init: Restore previously reverted option to mount block device for INIT_FILEPATH case
configs/stm3240g-eval/knxwm: Fix build breakage.
Author: Gregory Nutt <gnutt@nuttx.org>
configs: With recent changes to apps/ all configurations that build applications as modules must now also select CONFIG_APPS_LOADABLE.
Author: anchao <anchao@pinecone.net>
configs/sim/loadable: Add loadable demo for arch sim
Kconfig and tools/Makefile.unix and : add dynamic application loadable support
sched/group: Fix a deadlock when loading an ELF
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: GregoryN <gnutt@nuttx.org>
sched/mqueue/mq_notify.c: Fix - only part of struct copied to internal structure
As source adress the adress of the struct member sigev_value was used,
and it is not located the start of the struct.
This leads to invalid data being copied to internal structure.
Both source and destination should be of type struct sigevent* .
Approved-by: GregoryN <gnutt@nuttx.org>
binfmt/, libs/libc/unistd, and others: Rename CONFIG_EXECFUNCS_SYMTAB to CONFIG_EXECFUNCS_SYMTAB_ARRAY. Rename CONFIG_EXECFUNCS_NSYMBOLS to CONFIG_EXECFUNCS_NSYMBOLS_VAR. Unlike CONFIG_EXECFUNCS_NSYMBOLS, CONFIG_EXECFUNCS_NSYMBOLS_VAR holds the name of an 'int' variable that contains the number of symbols in the symbol table.
configs/sama5d4-ek: Partial update to knsh build instructions.
sched/clock: Move the implementation of clock() from libs/libc/time to sched/clock. This is necessary because it calls the (now) internal OS function clock_systimer. clock() is now accessed only via a system call in certain configuratins.
libs/libc/wqueue: Replace calls to clock_systimer() with calls to the equivalent clock().
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
The time slice check will decrement the currently running task's time slice allotment. If such a context switch occurs, then the newly started task will lost one could of that allotment before it even has a chance to run.
Change all Sony related copyright to conform with our company's internal rules.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
Fix SMP related bugs
* sched/sched: Fix a deadlock in SMP mode
Two months ago, I introduced sched_tasklist_lock() and
sched_tasklist_unlock() to protect tasklists in SMP mode.
Actually, this change works pretty well for HTTP audio
streaming aging test with lc823450-xgevk.
However, I found a deadlock in the scheduler when I tried
similar aging tests with DVFS autonomous mode where CPU
clock speed changed based on cpu load. In this case, call
sequences were as follows;
cpu1: sched_unlock()->sched_mergepending()->sched_addreadytorun()->up_cpu_pause()
cpu0: sched_lock()->sched_mergepending()
To avoid this deadlock, I added sched_tasklist_unlock() when calling
up_cpu_pause() and sched_addreadytorun(). Also, added
sched_tasklist_lock() after the call.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* libc: Add critical section in lib_filesem.c for SMP
To set my_pid into fs_folder atomically in SMP mode,
critical section API must be used.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* mm: Add critical section in mm_sem.c for SMP
To set my_pid into mm_folder atomically in SMP mode,
critical section API must be used.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* net: Add critical section in net_lock.c for SMP
To set my pid (me) into fs_folder atomically in SMP mode,
critical section API must be used.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
lc823450 smp test
* sched/clock: Replace critical section APIs with spin lock APIs in clock_gettime.c
This change will improve performance for SMP systems but nothing
changes for non-SMP systems. (Pls see include/nuttx/irq.h)
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* sched/sched: Remove unnecessary DEBUGASSERT in sched_removereadytorun.c
In SMP mode, rtrtcb is not always at the g_readytorun.head.
This change removes DEBUGASSERT() to avoid this condition.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
Fix signal handing for smp
* sched/signal: Remove SMP related logic in sig_dispatch.c
This change prevents from a deadlock in up_schedulesigaction.c
where inter-CPU signal handling is actually implemented.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
* arch/arm/src/armv7-m: Fix signal handling for SMP
In previous implementation, signal handling for SMP was incorrect.
Thus, for example, if an inter-CPU signal happened an incorret tcb
was signaled and caused ASSERT().
This change fixes the issues and works for both inter-CPU signal
handling and signal handling on the same CPU.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
