A method includes storing, with a first programmable processor, shared variable data to cache lines of a first cache of the first processor. The method further includes executing, with the first programmable processor, a store-with-release operation,…
Linux has supported a large number of SMP systems based on a variety of CPUs since the 2.0 kernel. Linux has done an excellent job of abstracting away differences among these CPUs, even in kernel code. One important difference is how CPUs allow memor…
A method and apparatus for preserving memory ordering in a cache coherent link based interconnect in light of partial and non-coherent memory accesses is herein described. In one embodiment, partial memory accesses, such as a partial read, is impleme…
如果不使用任何同步机制(例如 mutex 或 atomic),在多线程中读写同一个变量,那么,程序的结果是难以预料的.简单来说,编译器以及 CPU 的一些行为,会影响到程序的执行结果: 即使是简单的语句,C++ 也不保证是原子操作. CPU 可能会调整指令的执行顺序. 在 CPU cache 的影响下,一个 CPU 执行了某个指令,不会立即被其它 CPU 看见. 利用 C++ 的 atomic<T> 能完成对象的原子的读.写以及RMW(read-modify-write),而参数 std::m…
