大约有 3,000 项符合查询结果(耗时:0.0173秒) [XML]

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Context switches much slower in new linux kernels

...ance problem in recent kernels has to do with the switch to the intel_idle cpuidle driver from acpi_idle, the driver used in older kernels. Sadly, the intel_idle driver ignores the user's BIOS configuration for the C-states and dances to its own tune. In other words, even if you completely disable a...
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clang: how to list supported target architectures?

...the architectures listed, llc -march=ARCH -mattr=help will list "available CPUs" and "available features". The CPUs are generally just a convenient way of setting a default collection of features. But now for the bad news. There is no convenient table of triples in Clang or LLVM that can be dumped...
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Using Java with Nvidia GPUs (CUDA)

...of the matrix. In this case, one can expect that the GPU will outperform a CPU at a certain matrix size. Another example could be when many complex trigonometric computations (sine/cosine etc) are performed on "few" data elements. As a rule of thumb: You can assume that reading/writing one data el...
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Finding Number of Cores in Java

...logical threads actually available to the JVM (at startup I guess). Using CPU affinity the user/OS can restrict the number of "cores" a JVM sees. You can even do it on a running JVM but I'm not too sure how this influence availableProcessors(). – SyntaxT3rr0r ...
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Why does my application spend 24% of its life doing a null check?

...uting instructions, it is accessing memory. The execution core of a modern CPU is many times faster than the memory bus. A problem related to distance, the further an electrical signal has to travel, the harder it gets to get that signal delivered to the other end of the wire without it being corrup...
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What is the advantage of GCC's __builtin_expect in if else statements?

...ase precedes the foo case (as opposed to the C code). This can utilise the CPU pipeline better, since a jump thrashes the already fetched instructions. Before the jump is executed, the instructions below it (the bar case) are pushed to the pipeline. Since the foo case is unlikely, jumping too is un...
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【PM干货】2015年阿里业务型PM笔试题 - 项目管理 - 清泛网 - 专注C/C++及内核技术

...界面优化方案。 3、淘宝过程中经常存在用户信息泄露的问题,而快递公司必须知道买家的联系方式,淘宝商家利用这个联系方式向用户发送营销信息。 请设计一个流程来改善这个问题,必须包括: 1)分析淘宝卖家、买家和...
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Select random lines from a file

...0 --file lines_78000000000.txt > /dev/null 0.02s user 0.01s system 80% cpu 0.047 total The reason it is so fast, well I don't read the whole file and just move the file pointer 10 times and print the line after the pointer. Gitlab Repo Old attempt First I needed a file of 78.000.000.000 lines:...
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“register” keyword in C?

... It tells the compiler to try to use a CPU register, instead of RAM, to store the variable. Registers are in the CPU and much faster to access than RAM. But it's only a suggestion to the compiler, and it may not follow through. ...
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如何选择机器学习算法 - 大数据 & AI - 清泛网 - 专注IT技能提升

...ng-a-Machine-Learning-Classifier机器学习 算法如何针对某个分类问题决定使用何种机器学习算法? 当然,如果你真心在乎准确率,最好的途径就是测试一大堆各式各样的算法(同时确保在每个算法上也测试不同的参数),最后选择在...