Top "Futex" questions

"A futex (short for “fast userspace mutex”) is a kernel system call that programmers can use to implement basic locking, or as a building block for higher-level locking abstractions such as semaphores and POSIX mutexes or condition variables.

What is the difference between FUTEX_WAIT and FUTEX_WAIT_PRIVATE?

I have been tracing a process with strace and have seen entries such as: futex(0x7ffff79b3e00, FUTEX_…

linux strace futex
The futex facility returned an unexpected error code?

Two threads in same process using rwlock object stored in shared memory encounter crash during pthreads stress test. I spent …

multithreading linux-kernel pthreads futex
Why is a pthread mutex considered "slower" than a futex?

Why are POSIX mutexes considered heavier or slower than futexes? Where is the overhead coming from in the pthread mutex …

c linux pthreads futex
Java periodically hangs at futex and very low IO output

Currently my application periodically blocked in IO , and the output is very low . I use some command to trace the …

java io futex huge-pages
How to debug a futex contention shown in strace?

I'm debugging an issue in a multi-threaded linux process, where a certain thread appears to not execute for few seconds. …

linux multithreading futex
High system CPU usage when contending futex

I have observed that when the linux futexes are contended, the system spends A LOT of time in the spinlocks. …

linux spinlock futex
Python: Process hangs with futex(0x2a5fcc0, FUTEX_WAIT_PRIVATE, 0, NULL in multithreading

So I have a Queue : q = Queue.Queue() And I'm putting some items in it. items = ["First", "Second"] for val …

python multithreading queue futex
Futex based locking mechanism

Somebody can tell me an example of using locking mechanism based on futex? (for muticore x86 CPU, CentOS)

linux synchronization locking centos futex