mmap

问题 I am using mmap() to initialize a shared memory space for parent and child processes and the object happens to be a double char pointer (i.e. char** ). It's necessary because I'm going to be storing user input to this 2D array in a child process and the parent will be accessing this same data after the child has terminated. It wasn't hard to work this out after reading a little bit of documentation on mmap() , and it feels a lot like malloc() , but less of a commitment. Consider the code

问题 My mips32 application run against Valgrind fails in mmap function. It works fine if I run separately but when I run it against valgrind it fails with EINVAL each time. void * mem = (uint32_t *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, <fd>, mmap_size); 回答1: When the client application runs against the Valgrind, the Valgrind intercepts the mmap call made by the client. It then invokes the kernel's mmap function by setting the MAP_FIXED flag and also specifies the memory location to

问题 My mips32 application run against Valgrind fails in mmap function. It works fine if I run separately but when I run it against valgrind it fails with EINVAL each time. void * mem = (uint32_t *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, <fd>, mmap_size); 回答1: When the client application runs against the Valgrind, the Valgrind intercepts the mmap call made by the client. It then invokes the kernel's mmap function by setting the MAP_FIXED flag and also specifies the memory location to

问题 From the manual, I just know that mmap() maps a file to a virtual address space, so the file can be randomly accessed. But, it is unclear to me that whether the mapped file is loaded into memory immediately? I guess that kernel manages the mapped memory by pages, and they are loaded on demand, if I only do a few of reads and writes, only a few pages are loaded. Is it correct? 回答1: No, yes, maybe. It depends. Calling mmap generally only means that to your application, the mapped file's

问题 From the manual, I just know that mmap() maps a file to a virtual address space, so the file can be randomly accessed. But, it is unclear to me that whether the mapped file is loaded into memory immediately? I guess that kernel manages the mapped memory by pages, and they are loaded on demand, if I only do a few of reads and writes, only a few pages are loaded. Is it correct? 回答1: No, yes, maybe. It depends. Calling mmap generally only means that to your application, the mapped file's

来源： https://stackoverflow.com/questions/63348685/python-keeps-running-for-10mins-after-last-statement-in-program-when-there-is

来源： https://stackoverflow.com/questions/55768549/in-malloc-why-use-brk-at-all-why-not-just-use-mmap

来源： https://stackoverflow.com/questions/55768549/in-malloc-why-use-brk-at-all-why-not-just-use-mmap

来源： https://stackoverflow.com/questions/55768549/in-malloc-why-use-brk-at-all-why-not-just-use-mmap

来源： https://stackoverflow.com/questions/55768549/in-malloc-why-use-brk-at-all-why-not-just-use-mmap