f44a31c337
This is a memory monitoring interface implemented with reference to Linux's PSI (Pressure Stall Information),
which can send notifications when the system's remaining memory is below the threshold.
The following example code sets two different thresholds.
When the system memory is below 10MB, a notification is triggered.
When the system memory is below 20 MB, a notification (POLLPRI event) is triggered every 1s.
```
int main(int argc, FAR char *argv[])
{
struct pollfd fds[2];
int ret;
if (argc == 2)
{
char *ptr = malloc(1024*1024*atoi(argv[1]));
printf("Allocating %d MB\n", atoi(argv[1]));
ptr[0] = 0;
return 0;
}
fds[0].fd = open("/proc/pressure/memory", O_RDWR);
fds[1].fd = open("/proc/pressure/memory", O_RDWR);
fds[0].events = POLLPRI;
fds[1].events = POLLPRI;
dprintf(fds[0].fd, "%llu -1", 1024LLU*1024 * 10);
dprintf(fds[1].fd, "%llu 1000000", 1024LLU*1024 * 20);
while (1)
{
ret = poll(fds, 2, -1);
if (ret > 0)
{
printf("Memory pressure: POLLPRI, %d\n", ret);
}
}
return 0;
}
```
https://docs.kernel.org/accounting/psi.html
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
|
||
|---|---|---|
| .github | ||
| Documentation | ||
| arch | ||
| audio | ||
| binfmt | ||
| boards | ||
| cmake | ||
| crypto | ||
| drivers | ||
| dummy | ||
| fs | ||
| graphics | ||
| include | ||
| libs | ||
| mm | ||
| net | ||
| openamp | ||
| pass1 | ||
| sched | ||
| syscall | ||
| tools | ||
| video | ||
| wireless | ||
| .asf.yaml | ||
| .gitignore | ||
| .pre-commit-config.yaml | ||
| .yamllint | ||
| AUTHORS | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| INVIOLABLES.md | ||
| Kconfig | ||
| LICENSE | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
| ReleaseNotes | ||
README.md
Apache NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint. Scalable from 8-bit to 64-bit microcontroller environments, the primary governing standards in NuttX are POSIX and ANSI standards. Additional standard APIs from Unix and other common RTOSs (such as VxWorks) are adopted for functionality not available under these standards, or for functionality that is not appropriate for deeply-embedded environments (such as fork()).
For brevity, many parts of the documentation will refer to Apache NuttX as simply NuttX.
Getting Started
First time on NuttX? Read the Getting Started guide! If you don't have a board available, NuttX has its own simulator that you can run on terminal.
Documentation
You can find the current NuttX documentation on the Documentation Page.
Alternatively, you can build the documentation yourself by following the Documentation Build Instructions.
The old NuttX documentation is still available in the Apache wiki.
Supported Boards
NuttX supports a wide variety of platforms. See the full list on the Supported Platforms page.
Contributing
If you wish to contribute to the NuttX project, read the Contributing guidelines for information on Git usage, coding standard, workflow and the NuttX principles.
License
The code in this repository is under either the Apache 2 license, or a license compatible with the Apache 2 license. See the License Page for more information.