since the network IO is based on interrupt DMAcopy , why do we need the in out instruction to read data directly from the NIC register? ...
searched for a lot of information about multiplexing on the Internet. the general description is that the user thread registers with the demultiplexing function select, and when the relevant operation is completed, the user thread is informed to read the...
I used to start Windows, through ubuntu s Grub, but now I suddenly can t. I took a look at the efi file. What is the reason for reporting this error? (now you can only start Windows by changing BIOS) ...
-sharpinclude <iostream> -sharpinclude <queue> -sharpinclude <thread> -sharpinclude <mutex> -sharpinclude <condition_variable> using namespace std; mutex mtx; condition_variable produce, consume; queue<int> q; int m...
in the code on page 253 of the second edition of Unix Network programming Volume II: interprocess Communication (Chinese version), the author stores the semaphore in a shared memory through mmap, and then the parent and child processes can directly manip...
when watching Modern operating system, there are the following: conditional variables (unlike semaphores) will not exist in memory . If you send a semaphore to a semaphore that no thread is waiting for, the signal will be lost I would like to ask y...
in the book Modern operating system, there is a passage about threading in Chapter 2 because of the high cost of creating or revoking threads in the kernel, some systems adopt an "environmentally friendly " approach to reclaim their threads. When a...
cpu has a high load, which means there are more waiting processes, but cpu itself is idle or can handle other tasks, so why does the system change cards when the cpu load is high? ...
such as the title. Many articles on about the command free-m have mentioned the difference between cache and buffer, but the word cached is very confusing. At first I thought it was page cache, that was already used, but in fact cached buffers refers t...
after deleting the D disk from the computer, the space is allocated to the C disk system disk. Today s computers have a 128-gigabyte solid-state hard drive, known as disk C, and a 1T mechanical hard drive, known as disk E. A lot of software was inst...
problem description installing ubuntu18.04LTS, on macbbok shows an error near the end of the installation and is not seen clearly. Then call for restart, and enter the grub2 interface after reboot. I didn t install ubuntu on my computer s own hard d...
RT, in a 64-bit system, assuming that the actual memory is 3GB, what happens if the program requests 6GB memory and writes to the requested memory? ...
topic description there is a simple signal sample program in "CSAPP ". I compiled and ran the same code in Ubuntu, and the result was different from that given in the book, and it was different in the most important place: the signal was not queued. ...
sendfile and mmap are both typical zero-copy technologies, and sendfile is very efficient when files do not need to be modified. It is said that mmap is more suitable for the transfer of small files, while sendfile is more suitable for large files. How s...
on this question, I understand it like this: 1 to be exact, 32-bit CPU should support up to 4G memory because 32-bit CPU has 32 address buses, each line 0 or 1, a total of 2 ^ 32 possibilities, 2 ^ 32 memory addresses, each memory address corresponds t...
Peterson algorithm implements mutually exclusive access by pure software. But it only illustrates the mutual exclusion between the two processes, as shown below -sharpdefine FALSE 0 -sharpdefine TRUE 1 -sharpdefine N 2 int turn; int interested[N]; vo...
The thread also does not have a separate address space, and the thread cannot cause the main process to crash through return because the thread is often a separate function? Is there any way for the thread to also recycle the stack of the main process an...
does it seem that kernel cache has been removed from data replication? ...
when any thread X executes the wait () and notify () methods on any thread Y, it needs to acquire the lock first. it is said that the locking mechanism is to solve the critical resource problem, so does it allow threads to start and pause access to any ...
win7 system. as shown in the figure, create a bat file in the same directory, and compress the dist folder into dist.zip ....