processor

I know,there are some basic function in openMPI implementation for mapping the different processes to different cores of different sockets(if the system have more than one sockets). --bind-to-socket (first come first serve) --bysocket (round-robin,based on load balencing) --npersocket N (assign N processes to each socket) --npersocket N --bysocket (assign N process to each socket , but in a round-robin basis) --bind-to-core (binds one process to each core in a sequential fashion) --bind-to-core --bysocket (assign one process to each core ,but never leave any socket less utilized) --cpus-per

Can someone please explain if there's really any advantage to writing a multi-threaded piece of code that runs on a single processor with a single core? E.g., a method that processes document pages such that the pages are mutually exclusive w/r/t the aforementioned piece of code. At first glance, it doesn't seem like there'd be an advantage because true multi-threading is not possible. I.e., the OS would have to context switch the threads anyway. I'm wondering if just coding something in a single-threaded manner could actually be more efficient. Clearly, there are plenty of cases where writing

What book or website would you recommend to learn about QEMU? I'd like to see some usage examples as well as how to use the APIs. Brian Gianforcaro Best Resources: Main QEMU Usage Documentation Qemu Man Page - Invaluable resource when working with qemu. Quick Start Guide - Slightly ubuntu/debian specific. Covers KVM. Qemu Networking Guide - Great resource, super useful. Have fun qemu's a great tool. Brian G. db42 Some additional resources to understand and get started with the source code: http://vmsplice.net/~stefan/qemu-code-overview.pdf https://wiki.aalto.fi/download/attachments/41747647

The task is for architecture ColdFire processor MCF5271: I don't understand how many and what size cycles will be needed to perform a longword transfer to the CPU, or word transfers. I'm reading the chart and I don't see what the connection is? Any comments are very appreciated. I've attached 2 examples with the answers. DATA BUS SIZE The MCF5271 manual discusses the external interface of the processor in Chapter 17. The processor implements a byte-addressable address space with a 32-bit external data bus. The D[31:0] signals represent the data bus, the A[23:0] signals represent the address

I was studying about interrupts. So most architecture are interrupt driven, if everything is interrupt driven, how fast the processor can handle all of those. For example, while pressing a key board keys, it creates an interrupt asking the kernel to look for the buffer for new characters, in that case, how fast the processor can serve, also when an interrupt is put, the processor needs to switch to kernel space and that costs a lot in terms of context switch. So I assume, even after all these if the processor has a good performance, then I can only assume that the time between two key strokes

According to AMD manual segmentation can not be disabled. My question is why, why it's impossible? Another question, it says that 64-bit disables it, what does that mean? Is segmentation completly disabled on 64-bit mode? AMD Manual: https://s7.postimg.cc/hk15o6swr/Capture.png Introduction In 64-bit mode, whenever a non-null segment selector is loaded into any of the segment registers, the processor automatically loads the corresponding segment descriptor in the hidden part of the segment register, just like in protected/compatibility mode. However, the segment descriptors selected by the DS,

I have been looking for a way to log all memory accesses of a process/execution in Linux. I know there have been questions asked on this topic previously here like this Logging memory access footprint of whole system in Linux But I wanted to know if there is any non-instrumentation tool that performs this activity. I am not looking for QEMU/ VALGRIND for this purpose since it would be a bit slow and I want as little overhead as possible. I looked at perf mem and PEBS events like cpu/mem-loads/pp for this purpose but I see that they will collect only sampled data and I actually wanted the trace

OK, this question sounds simple but I am taken by surprise. In the ancient days when 1 Megabyte was a huge amount of memory, Intel was trying to figure out how to use 16 bits to access 1 Megabyte of memory. They came up with the idea of using segment and offset address values to generate a 20 bit address. Now, 20 bits gives 2^20 = 1,048,576 locations that can be addressed. Now assuming that we access 1 byte per address location we get 1,048,576/(1024*1024) = 2^20/2^20 Megabytes = 1 Megabyte. Ok understood. The confusion comes here, we have 16 bit data bus in the ancient 8086 and can access 2

I want to check whether multithreading is faster than single thread,then I make a demo here: public class ThreadSpeedTest { /** * @param args */ public static void main(String[] args) { System.out.println("cpu number:" + Runtime.getRuntime().availableProcessors()); singleThreadStart(); // secondThreadStart(); // fiveThreadStart(); } private static void sum() { long sum = 0; for (int i = 0; i < 1000000; i++) { sum += i; } System.out.println(sum); } private static void singleThreadStart() { new Thread(new Runnable() { public void run() { long start = System.nanoTime(); // sum(); // sum(); // sum