cpu

I need to find the architecture type of a CPU. I do not have access to /proc/cpuinfo, as the machine is running syslinux. I know there is a way to do it with inline ASM, however I believe my syntax is incorrect as my variable iedx is not being set properly. I'm drudging along with ASM, and by no means an expert. If anyone has any tips or can point me in the right direction, I would be much obliged. static int is64Bit(void) { int iedx = 0; asm("mov %eax, 0x80000001"); asm("cpuid"); asm("mov %0, %%eax" : : "a" (iedx)); if ((iedx) && (1 << 29)) { return 1; } return 0; } tyranid How many bugs can

I've got a Java application that is consuming 100% of the CPU most of the time (as indicated by cacti and top monitoring). We fired up YourKit (which confirms the CPU resource issue) and it identifies java.net.SocketInputStream.read(byte[], int, int) as the biggest hot spot at 15% of time. I believe they aren't accurately measuring CPU time for methods that perform blocking IO like SocketInputStream.read would. There are 6 other identified hot spots, but they account for less than 20% of accounted for CPU time combined. all in the 5%-1% range. So I know I have a problem, I can see the problem,

Which version is faster ? x * 0.5 or x / 2 Ive had a course at the university called computer systems some time ago. From back then i remember that multiplying two values can be achieved with comparably "simple" logical gates but division is not a "native" operation and requires a sum register that is in a loop increased by the divisor and compared to the dividend. Now i have to optimise an algorithm with a lot of divisions. Unfortunately its not just dividing by two so binary shifting is no option. Will it make a difference to change all divisions to multiplications ? update: I have changed

Do we still need to emulate 128bit integers in software, or is there hardware support for them in your average desktop processor these days? Z boson The x86-64 instruction set can do 64-bit*64-bit to 128-bit using one instruction ( mul for unsigned imul for signed each with one operand) so I would argue that to some degree that the x86 instruction set does include some support for 128-bit integers. If your instruction set does not have an instruction to do 64-bit*64-bit to 128-bit then you need several instructions to emulate this . This is why 128-bit * 128-bit to lower 128-bit operations can

Using C++ is there anyway I could get basic information about the computer? For example is there a way I could check how much memory is being used (by the whole computer not just my computer), the total memory available, virtual memory usage, CPU usage, networks stats and so on? I am using Mac OS X Snow Leopard but I would prefer a solution that could be implemented for all Mac OSs (i.e. Lion) Jeremy Friesner For system-wide memory usage information under MacOS/X, open and read the file /usr/bin/vm_stat, something like this: static double ParseMemValue(const char * b) { while((*b)&&(isdigit(*b

Can anyone tell me why Python's multiprocessing.cpu_count() function would return 1 when when called on a Jetson TK1 with four ARMv7 processors? >>> import multiprocessing >>> multiprocessing.cpu_count() 1 The Jetson TK1 board is more or less straight out of the box, and no one has messed with cpusets. From within the same Python shell I can print the contents of /proc/self/status and it tells me that the process should have access to all four cores: >>> print open('/proc/self/status').read() ----- (snip) ----- Cpus_allowed: f Cpus_allowed_list: 0-3 ----- (snip) ----- What else could be