内核中的打印输出到哪里去了? [英] Where does output of print in kernel go?

问题描述

我正在调试Linux(特别是ubuntu服务器9.04)的驱动程序，并且代码中有几个printf语句.

I am debugging a driver for linux (specifically ubuntu server 9.04), and there are several printf statements in the code.

在哪里可以查看这些语句的输出?

Where can I view the output of these statements?

我要执行的操作是使用proc文件系统写入内核. 打印代码是

What i'm trying to do is write to kernel using the proc file-system. The print code is

static int proc_fractel_config_write(struct file *file, const char *argbuf, unsigned long count, void *data)
{
    printk(KERN_DEBUG "writing fractel config\n");
    ...

在kern.log中，当我尝试覆盖文件/proc/net/madwifi/ath1/fractel_config(当然会随着时间变化)时，会看到以下消息.

In kern.log, I see the following message when i try to overwrite the file /proc/net/madwifi/ath1/fractel_config (with varying time of course).

[ 8671.924873] proc write 
[ 8671.924919] 

有什么解释吗?

推荐答案

这取决于分发，但是许多人使用klogd(8)从内核获取消息，并将消息记录到文件中(有时/var/log/dmesg或/var/log/kernel)或通过syslog(3)到系统日志.在后一种情况下，日志条目的结束位置将取决于syslogd(8)的配置.

It depends on the distribution, but many use klogd(8) to get the messages from the kernel and will either log them to a file (sometimes /var/log/dmesg or /var/log/kernel) or to the system log via syslog(3). In the latter case, where the log entries end up will depend on the configuration of syslogd(8).

关于dmesg命令的注意事项:内核消息存储在循环缓冲区中，因此大量输出将被覆盖.

One note about the dmesg command: Kernel messages are stored in a circular buffer, so large amounts of output will be overwritten.

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