The copy_from_user function copies a block of data from user space into a kernel buffer.
copy _ from_user函数将数据块从用户空间复制到内核缓冲区。
Then the data is copied by the kernel into the kernel buffer associated with the output socket.
然后由内核将数据拷贝到与输出套接字相关联的内核缓冲区。
The transferTo() method causes the file contents to be copied into a kernel buffer by the DMA engine.
transferTo()方法引发DMA引擎将文件内容拷贝到内核缓冲区。
Step two: data is copied from the kernel buffer into the user buffer, and the read system call returns.
所需的数据被从读取缓冲区拷贝到用户缓冲区，read()调用返回。
This significantly improves performance when the requested data amount is less than the kernel buffer size.
这在所需数据量小于内核缓冲区大小时极大地提高了性能。
This function accepts a pointer to a user space buffer, a pointer to a kernel buffer, and a length defined in bytes.
该函数接受一个指向用户空间缓冲区的指针、一个指向内存缓冲区的指针、以及一个以字节定义的长度。
Use of the intermediate kernel buffer (rather than a direct transfer of the data into the user buffer) might seem inefficient.
使用中间内核缓冲区(而不是直接将数据传输到用户缓冲区)看起来可能有点效率低下。
The data gets copied multiple times among the disk, kernel buffer, and user buffer before it is finally delivered to the application.
数据在被最终传入到应用程序前，在磁盘、内核缓冲区和用户缓冲区中被拷贝了多次。
The strncpy_from_user function copies a string from user space into a kernel buffer, given a user space source address and Max length.
strncpy _ from_user函数将一个字符串从用户空间复制到一个内核缓冲区，给定一个用户空间源地址和最大长度。
From here, depending on architecture, a call is made to copy from the user buffer to a kernel buffer with zeroing (of unavailable bytes).
从此开始，根据构架，为执行从用户缓冲区到内核缓冲区的零拷贝(不可用字节)而进行一个调用。
Unfortunately, this approach itself can become a performance bottleneck if the size of the data requested is considerably larger than the kernel buffer size.
不幸的是，如果所需数据量远大于内核缓冲区大小的话，这个方法本身可能成为一个性能瓶颈。
Using the intermediate buffer on the read side allows the kernel buffer to act as a "readahead cache" when the application hasn't asked for as much data as the kernel buffer holds.
在读取方面使用中间内核缓冲区，可以允许内核缓冲区在应用程序不需要内核缓冲区内的全部数据时，充当 “预读高速缓存（readahead cache）” 的角色。
Step two: data is copied from the kernel buffer into the user buffer, and the read system call returns. The return from the call caused a context switch from kernel back to user mode.
步骤二：数据从内核空间缓冲区复制到用户空间缓冲区，之后系统调用read返回，这导致了从内核空间向用户空间的上下文切换。
The kernel ring buffer is also used for some events after the system is booted. These include certain program failures and hot-plug events.
在系统启动后，内核环缓冲区也可以用于一些事件，其中包括某些程序失败和热插拔事件。
You may display the kernel ring buffer using the dmesg command, which displays these messages on standard output.
可以使用dmesg命令显示内核环缓冲区，会在标准输出上显示这些消息。
Because the buffer that I'll write to (page) is already in kernel space, I can manipulate it directly and use sprintf to write the next fortune.
由于我们刚才写入数据的缓冲区(page)已经在内核空间中了，因此可以直接对其进行操作，并使用sprintf来写入下一个fortune。
The page buffer provided here is in kernel space.
此处提供的page缓冲区在内核空间中。
The KERN_INFO symbol is a string that you can use to filter information from entering the kernel ring buffer (much like syslog).
kern_info符号是一个字符串，可以用来对进入内核回环缓冲区的信息进行过滤(非常类似于syslog)。
Tcp_sendspace -this controls how much buffer space in the kernel is used to buffer application data.
tcp _ sendspace——控制内核中用于缓冲应用程序数据的缓冲区空间大小。
The first copy (see Figure 1) is performed by the direct memory access (DMA) engine, which reads file contents from the disk and stores them into a kernel address space buffer.
直接内存存取(direct memory access,DMA)引擎执行了第一次拷贝(参见图1)，它从磁盘中读取文件内容，然后将它们存储到一个内核地址空间缓存区中。
Note that kernel output goes to the kernel ring buffer and not to stdout, because stdout is process specific.
注意，内核的输出进到了内核回环缓冲区中，而不是打印到stdout上，这是因为stdout是进程特有的环境。
It accepts a destination buffer (in kernel space), a source buffer (from user space), and a length defined in bytes.
它接受一个目的缓冲区(在内核空间)、一个源缓冲区(从用户空间)和一个以字节定义的长度。
Buffer activity for transfers, accesses, and cache (kernel block buffer cache) hit ratios.
传输、访问和缓存(内核块缓冲区缓存)命中率的缓冲区活动。
The block I/O buffer (kiobuf) in the 2.6 kernel allows I/O requests larger than PAGE_SIZE.
在 2.6 中块I/O缓冲区（kiobuf）允许 I/O请求可以比 PAGE_SIZE大。
Intermediate buffer copies - even those hidden in the kernel - can have a measurable cost.
中间缓冲区拷贝—甚至于那些隐藏在内核内的拷贝—都会产生一定的开销。
In addition, they tell the kernel to flush a dirty buffer after 3 seconds rather than 30, the default.
另外，它们告诉内核每隔3秒而不是30秒(缺省值)刷新“脏”缓冲区。
The size of the kernel ring buffer was originally 4kb but in recent kernels is sized at 16kb (and up to 1mb, depending on the architecture).
内核缓冲缓冲区的大小初始值为4kb，但是最新的内核大小已经升级到16 KB(在不同的体系架构上，这个值最高可以达到1mb)。
The string passed into printk is then copied into the kernel log buffer using a special function that manages the bounds of the ring (emit_log_char).
这个字符串会被传递给printk，然后它会被一个管理缓冲边界(emit_log_char)的特殊函数复制到内核日志缓冲区中。
This command USES the klogctl system call to read the kernel ring buffer and emit it to standard output (stdout).
这个命令使用klogctl系统调用来读取内核环缓冲区，并将它转发到标准输出(stdout)。
This command USES the klogctl system call to read the kernel ring buffer and emit it to standard output (stdout).
这个命令使用klogctl系统调用来读取内核环缓冲区，并将它转发到标准输出(stdout)。
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