affinity

How can I ensure that a process runs in a specific physical CPU core and thread?

假如想象 提交于 2019-12-06 00:33:36
This question asks about ensuring two processes run on the same CPU. Using sched_setaffinity I can limit a process to a number of logical CPUs, but how can I ensure that these are mapped to specific physical CPUs and threads? I expect that the mapping would be: 0 - CPU 0 thread 0 1 - CPU 0 thread 1 2 - CPU 1 thread 0 3 - CPU 1 thread 1 etc... where the number on the left is the relevant CPU used in sched_setaffinity . However, when I tried to test this, it appeared that this is not necessarily the case. To test this, I used the CPUID instruction, which returns the initial APIC ID of the

Set cpu affinity on a loadable linux kernel module

*爱你&永不变心* 提交于 2019-12-05 14:45:42
I need to create a kernel module that enables ARM PMU counters on every core in the computer. I have trouble setting the cpu affinity. Ive tried sched_get_affinity , but apparently, it only works for user space processes. My code is below. Any ideas? #define _GNU_SOURCE #include <linux/module.h> /* Needed by all modules */ #include <linux/kernel.h> /* Needed for KERN_INFO */ int init_module(void){ unsigned reg; /* enable user-mode access to the performance counters*/ asm volatile("MRC p15, 0, %0, C9, C14, 0\n\t" : "=r"(reg)); reg |= 1; asm volatile("MCR p15, 0, %0, C9, C14, 0\n\t" :: "r"(reg))

Using multiple CPU cores in TensorFlow

不打扰是莪最后的温柔 提交于 2019-12-05 06:41:23
问题 I have extensively studied other answers on TensorFlow and I just cannot seem to get it to use multiple cores on my CPU. According to htop, the following program only uses a single CPU core: import tensorflow as tf n_cpus = 20 sess = tf.Session(config=tf.ConfigProto( device_count={ "CPU": n_cpus }, inter_op_parallelism_threads=n_cpus, intra_op_parallelism_threads=1, )) size = 100000 A = tf.ones([size, size], name="A") B = tf.ones([size, size], name="B") C = tf.ones([size, size], name="C")

Android开发指南-框架主题-基础知识

谁都会走 提交于 2019-12-05 04:44:03
应用程序基础 关键类 Activity Service BroadcastReceiver ContentProvider Intent Android应用程序使用Java做为开发语言。aapt工具把编译后的Java代码连同其它应用程序需要的数据和资源文件一起打包到一个Android包文件中,这个文件使用.apk做为扩展名,它是分发应用程序并安装到移动设备的媒介,用户只需下载并安装此文件到他们的设备。单一.apk文件中的所有代码被认为是一个应用程序。 从很多方面来看,每个Android应用程序都存在于它自己的世界之中: 默认情况下,每个应用程序均运行于它自己的Linux进程中。当应用程序中的任意代码开始执行时,Android启动一个进程,而当不再需要此进程而其它应用程序又需要系统资源时,则关闭这个进程。 每个进程都运行于自己的Java虚拟机(VM)中。所以应用程序代码实际上与其它应用程序的代码是隔绝的。 默认情况下,每个应用程序均被赋予一个唯一的Linux用户ID,并加以权限设置,使得应用程序的文件仅对这个用户、这个应用程序可见。当然,也有其它的方法使得这些文件同样能为别的应用程序所访问。 使两个应用程序共有同一个用户ID是可行的,这种情况下他们可以看到彼此的文件。从系统资源维护的角度来看,拥有同一个ID的应用程序也将在运行时使用同一个Linux进程,以及同一个虚拟机。

第十五章 Kubernetes调度器

梦想与她 提交于 2019-12-05 04:22:51
一、 简介 Scheduler 是 kubernetes 的调度器,主要的任务是把定义的 pod 分配到集群的节点上。听起来非常简单,但有很多要考虑的问题: ①  公平:如何保证每个节点都能被分配资源 ②  资源高效利用:集群所有资源最大化被使用 ③  效率:调度的性能要好,能够尽快地对大批量的 pod 完成调度工作 ④  灵活:允许用户根据自己的需求控制调度的逻辑 Scheduler 是作为单独的程序运行的,启动之后会一直 坚挺 API Server ,获取 PodSpec.NodeName 为空的 pod ,对每个 pod 都会创建一个 binding (必须遵守的) ,表明该 pod 应该放到哪个节点上 二、 调度过程 调度分为几个部分: 1) 首先是过滤掉不满足条件的节点,这个过程称为 predicate(预选) ; 2) 然后对通过的节点按照优先级排序,这个是 priority(优选) ; 3) 最后从中选择优先级最高的节点。 如果中间任何一步骤有错误,就直接返回错误 (先预选,后优选) Predicate(预选) 有一系列的算法可以使用: ① PodFitsResources :节点上剩余的资源是否大于 pod 请求的资源 ② PodFitsHost :如果 pod 指定了 NodeName ,检查节点名称是否和 NodeName 匹配 ③

Pthread affinity before create threads

空扰寡人 提交于 2019-12-05 04:21:22
问题 I need to set the affinity (thread to core, eg: 1st thread to 1st core) before creating a thread. Something like KMP_AFFINITY in OpenMP . Is it possible? edit: I try in this way, but dont' work :/ void* DoWork(void* args) { int nr = (int)args; printf("Wątek: %d, ID: %d, CPU: %d\n", nr,pthread_self(), sched_getcpu()); } int main() { int count = 8; pthread_t threads[count]; pthread_attr_t attr; cpu_set_t mask; CPU_ZERO(&mask); pthread_attr_init(&attr); for (int i = 0; i < count ; i++) CPU_SET(i

To set the affinity of CPUs using C#

我的未来我决定 提交于 2019-12-04 13:00:57
问题 I have created a window application in C#.Now I want to set the CPU affinity for this application.I may have 2 processors,4 processors,8 processors or may be more than 8 processors. I want to set the cpu affinity using input from interface. How can i achieve this? How can it is possible to set the affinity using Environment.ProcessorCount? 回答1: Try this: Process.GetCurrentProcess().ProcessorAffinity = (System.IntPtr)2; Here's more about it. ProcessorAffinity represents each processor as a bit

Is it possible to set pthread CPU affinity in OS X?

喜你入骨 提交于 2019-12-04 10:02:43
In Linux there is a sched_setaffinity() function defined in sched.h , but I can't seem to find anything like that in Mac OS X 10.6 pthreads implementation... If it is not possible to set affinity, what is the default policy in OS X ? Kazuki Sakamoto Mac OS X has Thread Affinity API and you can use it with pthread ID as thread_policy_set(pthread_mach_thread_np(pthreadId), but, as far as I know, there are no APIs like sched_setaffinity. 来源: https://stackoverflow.com/questions/6183888/is-it-possible-to-set-pthread-cpu-affinity-in-os-x

setting cpu affinity for linux kernel, not process [closed]

百般思念 提交于 2019-12-04 03:25:18
I am having a hard time finding information about how to set cpu affinity for linux kernel (with all of its loaded modules), NOT for a specific process. This is because I want the kernel to run on CPU 0 all the time to handle I/O stuff, and not do any switches to run on other 3 CPUs because it may pollute L1 and L2 caches. Thanks in advance. Nulik Kernel work on behalf of processes will always happen on the CPU that makes the request. You can steer interrupts, though. Look at /proc/interrupts to identify the interrupts you want to move (say everything matching eth0 ) and set the affinity by

Pthread affinity before create threads

你。 提交于 2019-12-03 20:57:20
I need to set the affinity (thread to core, eg: 1st thread to 1st core) before creating a thread. Something like KMP_AFFINITY in OpenMP . Is it possible? edit: I try in this way, but dont' work :/ void* DoWork(void* args) { int nr = (int)args; printf("Wątek: %d, ID: %d, CPU: %d\n", nr,pthread_self(), sched_getcpu()); } int main() { int count = 8; pthread_t threads[count]; pthread_attr_t attr; cpu_set_t mask; CPU_ZERO(&mask); pthread_attr_init(&attr); for (int i = 0; i < count ; i++) CPU_SET(i, &mask); pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &mask); for(int i=0; i<count ; i++) {