// 方法一: 4kb 刷盘FileChannel fileChannel = new RandomAccessFile(file,"rw").getChannel();ByteBuffer byteBuffer = ByteBuffer.allocateDirect(_4kb);for(inti = 0; i < _4kb; i++) {byteBuffer.put((byte)0);}for(inti = 0; i < _GB; i += _4kb) {byteBuffer.position(0);byteBuffer.limi...
(fd);//文件映射,根据文件描述符在进程的打开文件表中找到file实例 if (!file) return -EBADF; if (is_file_hugepages(file)) len = ALIGN(len, huge_page_size(hstate_file(file))); retval = -EINVAL; if (unlikely(flags & MAP_HUGETLB && !is_file_hugepages(file))) goto out_fput; } ...
// 方法一: 4kb 刷盘FileChannel fileChannel=newRandomAccessFile(file,"rw").getChannel();ByteBuffer byteBuffer=ByteBuffer.allocateDirect(_4kb);for(int i=0;i<_4kb;i++){byteBuffer.put((byte)0);}for(int i=0;i<_GB;i+=_4kb){byteBuffer.position(0);byteBuffer.limit(_4kb);fileChannel.write(b...
"rb");// tm_file.txt是一个1G大小的文件std::cin>>b;// Step2:读取文件大小fseek(a,0,SEEK_END);intsize=ftell(a);fseek(a,0,SEEK_SET);std::cout<<" read size "<<size<<std::endl;std::cin>>b
FileChannel fileChannel =newRandomAccessFile(newFile("db.data"),"rw").getChannel(); MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE,0, filechannel.size(); MappedByteBuffer便是 Java 中的 mmap 操作类。 // 写 ...
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; lock_limit >>= PAGE_SHIFT; if (locked > lock_limit && !capable(CAP_IPC_LOCK)) return -EAGAIN; } --关于锁定的内存区在以后学习中再看,这里就不细看。 inode = file ? file->f_path.dentry->d_inode : NULL; --判断是否匿名...
fc95a91 will make --file-allocation=falloc faster by eliminating zero-fill. Crash does not sound good, so I'm now considering to add option to set maximum file size for mmap.Collaborator tatsuhiro-t commented Jan 28, 2016 --max-mmap-limit options was added by commit 8f51793Contributor...
// 方法一: 4kb 刷盘FileChannel fileChannel=newRandomAccessFile(file,"rw").getChannel();ByteBuffer byteBuffer=ByteBuffer.allocateDirect(_4kb);for(int i=0;i<_4kb;i++){byteBuffer.put((byte)0);}for(int i=0;i<_GB;i+=_4kb){byteBuffer.position(0);byteBuffer.limit(_4kb);fileChannel.write(...
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur; lock_limit >>= PAGE_SHIFT; if (locked > lock_limit && !capable(CAP_IPC_LOCK)) return -EAGAIN; } --关于锁定的内存区在以后学习中再看,这里就不细看。 inode = file ? file->f_path.dentry->d_inode : NULL; --判断是否匿名...
...二 系统调用mmap()用于共享内存的两种方式 (1)使用普通文件提供的内存映射:适用于任何进程之间;此时,需要打开或创建一个文件,然后再调用mmap();典型调用代码如下: fd=open(name...struct file *,struct vm_area_struct *); linux有2个方法建立页表: (1) 使用remap_pfn_range一次建立所有页表....