memory

Counting number of allocations into the Write Pending Queue - unexpected low result on NV memory

由 孤人 提交于 2020-04-13 08:06:08
问题 I am trying to use some of the uncore hardware counters, such as: skx_unc_imc0-5::UNC_M_WPQ_INSERTS . It's supposed to count the number of allocations into the Write Pending Queue. The machine has 2 Intel Xeon Gold 5218 CPUs with cascade lake architecture, with 2 memory controllers per CPU. linux version is 5.4.0-3-amd64. I have the following simple loop and I am reading this counter for it. Array elements are 64 byte in size, equal to cache line. for(int i=0; i < 1000000; i++){ array[i]

c# Call a method by memory address

由 时光毁灭记忆、已成空白 提交于 2020-04-11 04:47:35
问题 I am trying to call a function at a specified memory address in c#, here is how I would go about it in C: typedef void _do(int i); auto doActor = (_do*)0xAAAABEEF; doActor(1); How do I replicate this behavior in C# if at all possible? Very new to C# all help is appreciated. More in depth explanation of my situation: I am trying to create a tool that helps me automate certain processes within an executable. I decompiled the assembly of the main API and added my functionality (for the most part

How to get a move-only type out of a STL container?

由 ぐ巨炮叔叔 提交于 2020-04-11 04:27:07
问题 Let's consider an std::unordered_set of std::unique_ptr<T> as an example. Can I move an element of the set elsewhere ? #include <unordered_set> #include <iostream> #include <memory> #include <vector> int main() { std::unordered_set<std::unique_ptr<int>> mySet; mySet.insert(std::make_unique<int>(1)); mySet.insert(std::make_unique<int>(2)); mySet.insert(std::make_unique<int>(3)); std::vector<std::unique_ptr<int>> myVector; for (auto&& element : mySet) { std::cout << *element << std::endl; /

Why does the size of class in c++ depend on the public/private status of data members?

由 我们两清 提交于 2020-04-08 19:05:30
问题 From what i know, the size of a class in c++ depends on the below factors - Size of all non-static data members. Order of data members. If byte padding is enabled or not. Size of its immediate base class. The existence of virtual functions. Mode of inheritance (virtual inheritance). Now I've created 2 classes as below - class A{ int a; short s; int b; char d; };// kept a char at last on purpose to leave a "hole" class B : public A{ char c; }; now on checking the size of A and B I see size of

Why does the size of class in c++ depend on the public/private status of data members?

由 风流意气都作罢 提交于 2020-04-08 19:00:50
问题 From what i know, the size of a class in c++ depends on the below factors - Size of all non-static data members. Order of data members. If byte padding is enabled or not. Size of its immediate base class. The existence of virtual functions. Mode of inheritance (virtual inheritance). Now I've created 2 classes as below - class A{ int a; short s; int b; char d; };// kept a char at last on purpose to leave a "hole" class B : public A{ char c; }; now on checking the size of A and B I see size of

Why does the size of class in c++ depend on the public/private status of data members?

由 安稳与你 提交于 2020-04-08 19:00:39
问题 From what i know, the size of a class in c++ depends on the below factors - Size of all non-static data members. Order of data members. If byte padding is enabled or not. Size of its immediate base class. The existence of virtual functions. Mode of inheritance (virtual inheritance). Now I've created 2 classes as below - class A{ int a; short s; int b; char d; };// kept a char at last on purpose to leave a "hole" class B : public A{ char c; }; now on checking the size of A and B I see size of

Why does the size of class in c++ depend on the public/private status of data members?

由 青春壹個敷衍的年華 提交于 2020-04-08 19:00:26
问题 From what i know, the size of a class in c++ depends on the below factors - Size of all non-static data members. Order of data members. If byte padding is enabled or not. Size of its immediate base class. The existence of virtual functions. Mode of inheritance (virtual inheritance). Now I've created 2 classes as below - class A{ int a; short s; int b; char d; };// kept a char at last on purpose to leave a "hole" class B : public A{ char c; }; now on checking the size of A and B I see size of

[转帖]JVM源码分析之安全点safepoint

由 懵懂的女人 提交于 2020-04-08 08:52:36
JVM源码分析之安全点safepoint https://www.jianshu.com/p/c79c5e02ebe6 原来是这个意思.. 简书 占小狼 转载请注明原创出处，谢谢！ 上周有幸参加了一次关于JVM的小范围分享会，听完R大对虚拟机C2编译器的讲解，我的膝盖一直是肿的，能记住的实在有点少，能听进去也不多 1、什么时候进行C2编译，如何进行C2编译（这个实在太复杂） 2、C2编译的时候，是对整个方法体进行编译，而不是某个方法段 3、JVM中的safepoint 一直都知道，当发生GC时，正在执行Java code的线程必须全部停下来，才可以进行垃圾回收，这就是熟悉的STW（stop the world），但是STW的背后实现原理，比如这些线程如何暂停、又如何恢复？就比较疑惑了。 然而这一切的一切，都涉及到一个概念safepoint，openjdk的实现位于 openjdk/hotspot/src/share/vm/runtime/safepoint.cpp 什么是safepoint safepoint可以用在不同地方，比如GC、Deoptimization，在Hotspot VM中，GC safepoint比较常见，需要一个数据结构记录每个线程的调用栈、寄存器等一些重要的数据区域里什么地方包含了GC管理的指针。 从线程角度看

Spark: what's the advantages of having multiple executors per node for a Job?

由 試著忘記壹切 提交于 2020-04-08 06:00:09
问题 I am running my job on AWS-EMR cluster. It is a 40 nodes cluster using cr1.8xlarge instances. Each cr1.8xlarge has 240G memory and 32 cores. I can run with the following config: --driver-memory 180g --driver-cores 26 --executor-memory 180g --executor-cores 26 --num-executors 40 --conf spark.default.parallelism=4000 or --driver-memory 180g --driver-cores 26 --executor-memory 90g --executor-cores 13 --num-executors 80 --conf spark.default.parallelism=4000 Since from the job-tracker website, the

Spark: what's the advantages of having multiple executors per node for a Job?

由 99封情书 提交于 2020-04-08 05:59:07
问题 I am running my job on AWS-EMR cluster. It is a 40 nodes cluster using cr1.8xlarge instances. Each cr1.8xlarge has 240G memory and 32 cores. I can run with the following config: --driver-memory 180g --driver-cores 26 --executor-memory 180g --executor-cores 26 --num-executors 40 --conf spark.default.parallelism=4000 or --driver-memory 180g --driver-cores 26 --executor-memory 90g --executor-cores 13 --num-executors 80 --conf spark.default.parallelism=4000 Since from the job-tracker website, the
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