Commit Graph

16 Commits

Author SHA1 Message Date
Xiang Xiao
1fb8c13e5e Replace nxsem_timedwait_uninterruptible with nxsem_tickwait_uninterruptible
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
2022-05-15 13:55:58 +03:00
chao.an
0b18cfbd9a mm/iob: add support of alloc with timeout iob_timedalloc()
Signed-off-by: chao.an <anchao@xiaomi.com>
2022-02-17 11:55:29 -03:00
YAMAMOTO Takashi
5b1f2dff5f iob_tryalloc: Fix throttled allocation
If threads are blocking for throttled allocation,
g_throttle_sem.semcount doesn't represent the number of
usable IOBs well.

Note: For non-throttled allocations, the g_iob_committed mechanism
is a rescue. But there is no equivalent for throttled allocations.
2021-08-02 11:25:55 -07:00
YAMAMOTO Takashi
e96a870485 iob_tryalloc: Remove a wrong assertion 2021-08-02 11:25:55 -07:00
Alin Jerpelea
acb8ad4c7b mm: nxstyle fixes
Nxstyle fixes to pass CI

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-02-09 01:21:53 -08:00
Alin Jerpelea
bcee9c391c mm: Author Gregory Nutt: update licenses to Apache
Gregory Nutt has submitted the SGA and we can mograte the licenses
to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-02-09 01:21:53 -08:00
Xiang Xiao
5c80b94820 Replace #include <semaphore.h> to #include <nuttx/semaphore.h>
Since the kernel side should call nxsem_xxx instead and remove the unused inclusion
2020-02-01 08:27:30 -06:00
Xiang Xiao
6a3c2aded6 Fix wait loop and void cast (#24)
* 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
2020-01-02 10:54:43 -06:00
Anthony Merlino
70404ed0dc Merged in antmerlino/nuttx/iobinstrumentation (pull request #1001)
Iobinstrumentation

* mm/iob: Introduces producer/consumer id to every iob call. This is so that the calls can be instrumented to monitor the IOB resources.

* iob instrumentation - Merges producer/consumer enumeration for simpler IOB user.

* fs/procfs: Starts adding support for /proc/iobinfo

* fs/procfs: Finishes first pass of simple IOB user stastics and /proc/iobinfo entry

Approved-by: Gregory Nutt <gnutt@nuttx.org>
2019-08-16 22:42:25 +00:00
Xiang Xiao
4721381d1c mm/iob/iob_alloc.c: iob_allocwait should decrease semcount manually. 2019-01-26 09:24:12 -06:00
Gregory Nutt
7cc63f90d9 sched/semaphore: sem_trywait() modifies the errno value and, hence, should not be used within the OS. Use nxsem_trywait() instead. 2017-10-05 07:59:06 -06:00
Gregory Nutt
9568600ab1 Squashed commit of the following:
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.
2017-10-04 15:22:27 -06:00
Gregory Nutt
42a0796615 Squashed commit of the following:
sched/semaphore:  Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable.  Changed all references to sem_post in the OS to nxsem_post().

    sched/semaphore:  Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable.  Changed all references to sem_destroy() in the OS to nxsem_destroy().

    libc/semaphore and sched/semaphore:  Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable.  Changed all references to sem_setprotocol in the OS to nxsem_setprotocol().  sem_getprotocol() was not used in the OS
2017-10-03 15:35:24 -06:00
Gregory Nutt
6a3800f611 There can be a failure in IOB allocation to some asynchronous behavior caused by the use of sem_post(). Consider this scenario:
Task A holds an IOB.  There are no further IOBs.  The value of semcount is zero.
Task B calls iob_alloc().  Since there are not IOBs, it calls sem_wait().  The v
alue of semcount is now -1.

Task A frees the IOB.  iob_free() adds the IOB to the free list and calls sem_post() this makes Task B ready to run and sets semcount to zero NOT 1.  There is one IOB in the free list and semcount is zero.  When Task B wakes up it would increment the sem_count back to the correct value.

But an interrupt or another task runs occurs before Task B executes.  The interrupt or other tak takes the IOB off of the free list and decrements the semcount.  But since semcount is then < 0, this causes the assertion because that is an invalid state in the interrupt handler.

So I think that the root cause is that there the asynchrony between incrementing the semcount.  This change separates the list of IOBs:  Currently there is only a free list of IOBs.  The problem, I believe, is because of asynchronies due sem_post() post cause the semcount and the list content to become out of sync.  This change adds a new 'committed' list:  When there is a task waiting for an IOB, it will go into the committed list rather than the free list before the semaphore is posted.  On the waiting side, when awakened from the semaphore wait, it will expect to find its IOB in the committed list, rather than free list.

In this way, the content of the free list and the value of the semaphore count always remain in sync.
2017-05-16 11:03:35 -06:00
Gregory Nutt
d3b9f5b37f Syslog buffering: Use IOBs to buffer data, not an on-stack buffer 2017-05-10 17:36:08 -06:00
Gregory Nutt
2043e1a114 IOBs: Move from driver/iob to a better location in mm/iob 2017-05-09 07:35:30 -06:00