Intel s procs that end in g
![intel s procs that end in g intel s procs that end in g](https://letstechready.com/wp-content/uploads/2021/05/Intel_Core_2020_logo.png)
The low-level interface does not make use of the concept of a GTID, and can be used by programs containing arbitrarily many levels of parallelism.ĭoes not bind OpenMP threads to particular thread contexts however, if the operating system supports affinity, the compiler still uses the OpenMP thread affinity interface to determine machine topology. Hence, their usefulness is limited in programs containing nested parallelism. The high-level and mid-level interfaces rely heavily on this concept. In the normal case where all other threads are created by the library and when there is no nested parallelism, then n-threads-var - 1 new threads are created with GTIDs ranging from 1 to ntheads-var - 1, and each thread's GTID is equal to the OpenMP thread number returned by function omp_get_thread_num(). The thread that first initializes the library is given GTID 0. The term OpenMP Global Thread ID (GTID) refers to an integer which uniquely identifies all threads known to the Intel OpenMP runtime library. The term package refers to a single or multi-core processor chip. The total number of processing elements on the machine is referred to as the number of OS thread contexts.Įach processing element is referred to as an Operating System processor, or O S proc.Įach OS processor has a unique integer identifier associated with it, called an OS proc ID. The following terms are used in this section
![intel s procs that end in g intel s procs that end in g](https://www.cowcotland.com/images/news/2021/11/intel-raptor-lake-s-q3-2022-f.jpg)
For example, you can set the affinity type KMP_AFFINITY to disabled, which disables the low-level affinity interface, or you could use the KMP_AFFINITY or GOMP_CPU_AFFINITY environment variables to set the initial affinity mask, and then retrieve the mask with the low-level API interface. In addition, you can specify certain options of the KMP_AFFINITY environment variable to affect the behavior of the low-level API interface. This interface is similar in nature to sched_setaffinity and related functions on Linux* systems or to SetThreadAffinityMask and related functions on Windows* systems. The low-level affinity interface uses APIs to enable OpenMP threads to make calls into the OpenMP runtime library to explicitly specify the set of processors on which they are to be run.
![intel s procs that end in g intel s procs that end in g](https://m.media-amazon.com/images/I/61qUfPKfqJL._SL1200_.jpg)
INTEL S PROCS THAT END IN G WINDOWS
The GOMP_CPU_AFFINITY environment variable is supported on Linux systems only, but users on Windows or Linux systems can use the similar functionality provided by the KMP_AFFINITY environment variable. This interface provides compatibility with the GNU gcc* GOMP_CPU_AFFINITY environment variable, but you can also invoke it by using the KMP_AFFINITY environment variable. The mid-level affinity interface uses an environment variable to explicitly specifies which processors (labeled with integer IDs) are bound to OpenMP threads. This interface is controlled entirely by the KMP_AFFINITY environment variable. The high-level affinity interface uses an environment variable to determine the machine topology and assigns OpenMP threads to the processors based upon their physical location in the machine. There are three types of interfaces you can use to specify this binding, which are collectively referred to as the Intel OpenMP Thread Affinity Interface: The Intel compiler's OpenMP runtime library has the ability to bind OpenMP threads to physical processing units. The thread affinity interface is supported only for Intel processors.
INTEL S PROCS THAT END IN G MAC
Thread affinity is supported on Windows OS systems and versions of Linux OS systems that have kernel support for thread affinity, but is not supported by Mac OS* X. Depending upon the topology of the machine, thread affinity can have a dramatic effect on the execution speed of a program. Thread affinity restricts execution of certain threads (virtual execution units) to a subset of the physical processing units in a multiprocessor computer. Depending on the system (machine) topology, application, and operating system, thread affinity can have a dramatic effect on the application speed. The interface is controlled using the KMP_AFFINITY environment variable. The Intel runtime library has the ability to bind OpenMP threads to physical processing units.