WebJul 30, 2014 · I'm not aware yet about Linux kernel programming specifics, so here is a partial (general) answer. On x86, this operation carries full memory fence with it, there is no need in mfence/lfence/sfence around cmpxchg op.. On other architectures with relaxed memory model, it can be coupled with other memory semantics, e.g. "release", … WebOn Sun, Mar 05, 2024 at 09:56:19PM +0100, Uros Bizjak wrote: > Cast _oldp to the type of _ptr to avoid incompatible-pointer-types warning. Can you give an example of where we are passing an incompatible pointer? That sounds indicative of a …

> "Verifying and Optimizing Compact NUMA-Aware Locks on Weak

WebMar 18, 2024 · share. Every cmpxchg define (_relaxed, _acquire, _release, vanilla) … WebAug 2, 2014 · Frequently processors have special lower latency instructions that can operate without the typical synchronization overhead, but still provide some sort of relaxed atomicity guarantees. The x86, for example, can execute RMW (Read Modify Write) instructions like inc/dec/cmpxchg without the lock prefix and the associated latency penalty. its norman oklahoma

[RFC PATCH v2 3/6] riscv/cmpxchg: Deduplicate arch_cmpxchg() …

WebMar 17, 2011 · If the fast-path fails to get the lock, your spin-loop should check read-only before retrying xchg or cmpxchg, to avoid having all the waiters hammering on the cache line and delaying the thread trying to unlock.(Use _mm_pause() and atomic_load_explicit(lockaddr, memory_order_relaxed) in the spinloop. Avoid having … WebMay 6, 2009 · Compare EDX:EAX register to 64-bit memory location. If equal, set the … WebNov 10, 2012 · Since you are using atomic_cmpxchg, which is a part of an optional extension in OpenCL, you need to check that your device supports it, and then enable it in your kernel code: Check that cl_khr_global_int32_base_atomics is listed in the extensions returned by clGetDeviceInfo (..., CL_DEVICE_EXTENSIONS, ...) Add the following to the … its nobbut snow doctor