Could Qt Thread be marked on one CPU？

Mihan

Hi all

I want some threads could only run on one CPU so that the main thread (UI) could be smooth.

QThread::currentThreadId()  //to get current tid
sched_setaffinity()    // to set CPU

However, I still have a doubt:

Could I do that in the thread or out of the thread, what about QtConcurrent::run()?

The topic in chinese is as follow
Chinese - 如何指定线程到某一CPU

Hope someine help

Best regards
Mihan

Christian Ehrlicher

No that's not possible - if you really want such specific stuff you have to use OS specific calls.

Mihan

Sorry for late.

Yes, sched_setaffinity() is the function in Linux.

/*sched.h*/
/* Set the CPU affinity for a task */
extern int sched_setaffinity (__pid_t __pid, size_t __cpusetsize,
			      const cpu_set_t *__cpuset) __THROW;

but I don't know if it works well.

JoeCFD

@Mihan said in Could Qt Thread be marked on one CPU？:

sched_setaffinity()

From its definitions it is what you need.
https://stackoverflow.com/questions/10490756/how-to-use-sched-getaffinity-and-sched-setaffinity-in-linux-from-c
https://cpp.hotexamples.com/examples/-/-/sched_setaffinity/cpp-sched_setaffinity-function-examples.html