multicore

问题 I was reading the Intel instruction set guide 64-ia-32 guide to get an idea on memory fences. My question is that for an example with SFENCE, in order to make sure that all store operations are globally visible, does the multi-core CPU parks all the threads even running on other cores till the cache coherence achieved ? 回答1: Barriers don't make other threads/cores wait. They make some operations in the current thread wait , depending on what kind of barrier it is. Out-of-order execution of

问题 I was reading the Intel instruction set guide 64-ia-32 guide to get an idea on memory fences. My question is that for an example with SFENCE, in order to make sure that all store operations are globally visible, does the multi-core CPU parks all the threads even running on other cores till the cache coherence achieved ? 回答1: Barriers don't make other threads/cores wait. They make some operations in the current thread wait , depending on what kind of barrier it is. Out-of-order execution of

问题 I was reading the Intel instruction set guide 64-ia-32 guide to get an idea on memory fences. My question is that for an example with SFENCE, in order to make sure that all store operations are globally visible, does the multi-core CPU parks all the threads even running on other cores till the cache coherence achieved ? 回答1: Barriers don't make other threads/cores wait. They make some operations in the current thread wait , depending on what kind of barrier it is. Out-of-order execution of

问题 If I spawn 2 threads on a single core PC does it ever access for example an ArrayList in the same time so it will throw ConcurrentModificationException ? My gut tells me although there are 2 threads, they cannot achieve true parallelism because there is a single core and what it can do mostly is to jump from one thread to another but without executing an instruction such as arrayList.add(element) in the same time. 回答1: TL;DR: Yes List<String> myList = new ArrayList<String>(Arrays.asList("My

问题 If I spawn 2 threads on a single core PC does it ever access for example an ArrayList in the same time so it will throw ConcurrentModificationException ? My gut tells me although there are 2 threads, they cannot achieve true parallelism because there is a single core and what it can do mostly is to jump from one thread to another but without executing an instruction such as arrayList.add(element) in the same time. 回答1: TL;DR: Yes List<String> myList = new ArrayList<String>(Arrays.asList("My

问题 If I spawn 2 threads on a single core PC does it ever access for example an ArrayList in the same time so it will throw ConcurrentModificationException ? My gut tells me although there are 2 threads, they cannot achieve true parallelism because there is a single core and what it can do mostly is to jump from one thread to another but without executing an instruction such as arrayList.add(element) in the same time. 回答1: TL;DR: Yes List<String> myList = new ArrayList<String>(Arrays.asList("My

问题 If I spawn 2 threads on a single core PC does it ever access for example an ArrayList in the same time so it will throw ConcurrentModificationException ? My gut tells me although there are 2 threads, they cannot achieve true parallelism because there is a single core and what it can do mostly is to jump from one thread to another but without executing an instruction such as arrayList.add(element) in the same time. 回答1: TL;DR: Yes List<String> myList = new ArrayList<String>(Arrays.asList("My

来源： https://stackoverflow.com/questions/45382914/parallel-memory-access-on-modern-processors

来源： https://stackoverflow.com/questions/10403201/8-logical-threads-at-4-cores-will-at-a-maximum-run-4-times-faster-in-parallel

问题 I have this program that I've written in PyCharm. This program should be running for a week or so, and it is very processor-needy. So when I run it I pretty much have no use of my notebook, as it becomes very laggy. Is there a way to somehow tell PyCharm to use first three of my cores and leave one for other programms so they can operate normally? 回答1: Go into task manager Find the running task (it probably won't be the main pycharm window) Right click and select "go to details" Right click