Developer Guide
Developer Guide for Intel® oneAPI Math Kernel Library macOS*
                    
                        ID
                        766688
                    
                
                
                    Date
                    3/31/2023
                
                
                    Public
                
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                                Getting Help and Support
                            
                        
                            
                            
                                What's New
                            
                        
                            
                            
                                Notational Conventions
                            
                        
                            
                            
                                Related Information
                            
                        
                            
                                Getting Started
                            
                            
                        
                            
                                Structure of the Intel® oneAPI Math Kernel Library
                            
                            
                        
                            
                                Linking Your Application with the Intel® oneAPI Math Kernel Library
                            
                            
                        
                            
                                Managing Performance and Memory
                            
                            
                        
                            
                                Language-specific Usage Options
                            
                            
                        
                            
                                Obtaining Numerically Reproducible Results
                            
                            
                        
                            
                                Coding Tips
                            
                            
                        
                            
                                Managing Output
                            
                            
                        
                            
                                Working with the Intel® oneAPI Math Kernel Library Cluster Software
                            
                            
                        
                            
                                Managing Behavior of the Intel® oneAPI Math Kernel Library with Environment Variables
                            
                            
                        
                            
                                Configuring Your Integrated Development Environment to Link with Intel® oneAPI Math Kernel Library
                            
                            
                        
                            
                                Intel® oneAPI Math Kernel Library Benchmarks
                            
                            
                        
                            
                                Appendix A: Intel® oneAPI Math Kernel Library Language Interfaces Support
                            
                            
                        
                            
                                Appendix B: Support for Third-Party Interfaces
                            
                            
                        
                            
                                Appendix C: Directory Structure in Detail
                            
                            
                        
                            
                            
                                Notices and Disclaimers
                            
                        
                    
                
                                                
                                                
                                                    
                                                    
                                                        OpenMP* Threaded Functions and Problems
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Functions Threaded with Intel® Threading Building Blocks
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Avoiding Conflicts in the Execution Environment
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Techniques to Set the Number of Threads
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Setting the Number of Threads Using an OpenMP* Environment Variable
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Changing the Number of OpenMP* Threads at Run Time
                                                    
                                                    
                                                
                                                    
                                                        Using Additional Threading Control
                                                    
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Calling oneMKL Functions from Multi-threaded Applications
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Using Intel® Hyper-Threading Technology
                                                    
                                                    
                                                
                                            
                                        Setting the Number of Threads Using an OpenMP* Environment Variable
You can set the number of threads using the environment variable OMP_NUM_THREADS. To change the number of OpenMP threads, in the command shell in which the program is going to run, enter:
export OMP_NUM_THREADS=<number of threads to use>.
 Parent topic: Improving Performance with Threading