- `g_iob_sem.semcount` must be equal to the total number of free IOBs.
It can also be negative if there are no free IOBs and there are threads
waiting for an IOB.
- g_throttle_sem.semcount represents the number of IOBs available for
throttled IOB allocations. Like any other semaphore, it should only go
negative if there is a thread waiting for it.
- Both semaphores are related to the same resource (free IOBs), hence,
they must be incremented/decremented simultaneously:
- Whenever a IOB buffer is freed, if a thread is waiting for a
non-throttled IOB or a thread is waiting for a throttled IOB and we
have at least `CONFIG_IOB_THROTTLE` buffers available, the IOB is put
in the committed list (`g_iob_committed`). Otherwise, it is put in the
common free list (`g_iob_freelist`).
- `g_iob_sem` is always incremented when an IOB buffer is freed, but
`g_throttle_sem` is incremented only if we have at least CONFIG_IOB_THROTTLE
buffers free.
- Both semaphores are posted with the schedule locked to avoid any
mismatches in the semaphores count.
- If a task is waiting for an IOB semaphore (`iob_allocwait`) is
awakened and would check the `g_iob_committed`. The highest priority
task waiting for a semaphore will be awakened first.
If the CAN stack receiving packets fast, but the application layer reading packets slow. Then `conn->readahead` will continue to grow, leading to memory leaks. Finally CAN stack potentially starve out all IOB buffers. To prevent memory leaks, users can restrict can socket buffer length.
Signed-off-by: gaohedong <gaohedong@xiaomi.com>
Support the network interface card driver to receive zero copies of packets and send and receive giant frame packets, allowing drivers to initialize the DMA buffer to the iob structure, and we can apply for IOB with large memory
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
rndis header length is 36, L2 header is 14, IPv6 header is 40, tcp header is 56 when sack option count is 4(default max_ofosegs is 4). so the iob bufsize should greater than we need.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.com>
If we apply `iob_reserve` on an IOB with `io_offset != 0`, the `head->io_pktlen` and `iob->io_len` will become wrong value, because we only need to trim `offset - iob->io_offset`.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
if there are two throttled wait, when iob_free occurs, one of wait
will be awakened to execute iob_alloc_committed, but it will fail
to execute, sem will be posted at this time, then another wait will
be awakened. after the other wait thread is awakened, This step is
repeated. the two threads are in the critical_section state and
cannot be switched to other threads. then cpu will busy util timeout.
Signed-off-by: zhanghongyu <zhanghongyu@xiaomi.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>
We don't want to get a NULL pointer after iob_pack on an IOB chain with
several iobs with length 0, it should return one IOB with length 0.
Otherwise each place calls iob_pack needs to check the result.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
In the past, header file paths were generated by the incdir command
Now they are generated by concatenating environment variables
In this way, when executing makefile, no shell command will be executed,
it will improve the speed of executing makfile
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
In the past, predefined macros were generated by define.sh scripts
Now they are generated by concatenating environment variables
In this way, when executing makefile, no shell command will be executed,
it will improve the speed of executing makfile
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
since it is impossible to track producer and consumer
correctly if TCP/IP stack pass IOB directly to netdev
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
The operations of struct iob_queue_s in qh_head & qh_tail are performed with interrupts disabled.
change iflags to flags
add header file ref
update for check
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.
Gregory Nutt is the copyright holder for those files and he has submitted the
SGA as a result we can migrate the licenses to Apache.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
Tiago Medicci Serrano