processors

问题 I thought I've always understood why Java was portable, until I took Computer Organization. This is my interpretation of a C program from start to finish: C program --> compiler --> assembly --> machine code --> ISA --> micro architecture (how the computer interprets ISA) --> logic gate --> circuit --> device Where the compiler must have knowledge of the ISA. Also, the assembly and machine code will vary based on ISA. Java is as such: (inside JVM): Java program --> compiler --> bytecode

问题 I have to use spring batch to read the file and process the contents in batches. I thought of using remote chunking, but it wont meet my actual requirement. I just mentioned my requirement below; ____Item Processor1----> | | Item Reader --->Item --Item Processor2----> ---ItemWriter | | | -- Item Processor n---> Say for example, if my commit count is 20, I wanted the ItemReader to read 20 items and should distribute to the concurrent processors and the same should commit by the ItemWriter, and

问题 Along with my settings.py and urls.py file, I created a context_processors.py file in the same directory. This is my context_processors.py file: from django.contrib.auth.forms import AuthenticationForm def loginFormCustom(request): form = AuthenticationForm() return {'loginForm': form,} and this is my views.py: from django.template import RequestContext from tp.context_processors import loginFormCustom def main_page(request): variables = { 'title': 'This is the title of the page' } return

问题 This question already has an answer here : Performance Issues with newFixedThreadPool vs newSingleThreadExecutor (1 answer) Closed 6 years ago . What is the difference between- newSingleThreadExecutor vs newFixedThreadPool(20) in terms of Operating System and Programming point of view. Whenever I am running my program using newSingleThreadExecutor my program works very well and end to end latency(95th percentile) comes around 5ms . But as soon as I start running my program using-

问题 On unix, how could we know whether the system is multiprocessor or uniprocessor? 回答1: Some times we have to answer owr own question :) On Solaris run the command /usr/sbin/psrinfo -v|grep "Status of processor"|wc -l On AIX run the command lsdev -C|grep Process|wc -l On HP-UX run the following commands (requires superuser privileges): P=`echo processor_count/D | adb -k /stand/vmunix /dev/mem |tail -1|awk '{print $2}'` echo "The number of processors on `hostname` = $P" On Tru64 run the command

问题 Just wondering if threading with one processor improves things for me. I am building an application that performs data intensive calculations (fft on pcm data) while a UI is running and needs to run smoothly. I have been looking at AsyncTask but was thinking: If I have a single core processor (600 MHz ARM 11 processor) running on my Optimus One, will threading make a difference? I thought for threads to run independantly you would need multiple processors? Or have I gone wrong somewhere? 回答1:

问题 Sorry, I'm sure making a silly mistake, but did not work out. I'm compiling a simple mpi hello world: #include <stdio.h> #include <mpi.h> int main (argc, argv) int argc; char *argv[]; { int rank, size; MPI_Init (&argc, &argv); /* starts MPI */ MPI_Comm_rank (MPI_COMM_WORLD, &rank); /* get current process id */ MPI_Comm_size (MPI_COMM_WORLD, &size); /* get number of processes */ printf( "Hello world from process %d of %d\n", rank, size ); MPI_Finalize(); return 0; } And: > mpicc -o hello_world

问题 Following is my code in MPI, which I run it over a core i7 CPU (quad core), but the problem is it shows me that it's running under 1 processor CPU, which has to be 4. int main(int argc, char *argv[]) { int rank, size; MPI_Init(&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &rank); MPI_Comm_size(MPI_COMM_WORLD, &size); printf("Hello world! I am %d of %d\n", rank, size); MPI_Finalize(); return 0; } I was wondering if the problem is with MPI library or sth else? Here is the result that it shows me

问题 I recently bought a Moto Atrix 2 mobile. When I tried to look at the processor specs in the phone, Runtime.getRuntime().availableProcessors() returned 1. /proc/cpuinfo too had information about just processor 0. Out of curiosity I checked the same in my friend's Samsung Galaxy S2, which is again a dual core phone. This too showed that no. of cores is 1. I checked the same in my Moto xoom tablet which is again dual core. This time availableProcessors() returned 2 and cpuinfo also had both

问题 In Java there's the method Runtime.getRuntime().availableProcessors() which has the following Javadoc: Returns the number of processors available to the Java virtual machine. This value may change during a particular invocation of the virtual machine. How can the value actually change? Under what circumstances would there be less processors available to the JVM than physically installed for example? Jonas 回答1: The Linux command taskset(1) can be used to force processes to use a specific CPU