Oprofile错误：无法打开配置文件设备：设备或资源繁忙

Question

I'm struggling to run oprofile on my system because of an annoying error:

$ sudo opcontrol --setup --vmlinux=/usr/lib/debug/lib/modules/`uname -r`/vmlinux
$ sudo opcontrol --start
ATTENTION: Use of opcontrol is discouraged.  Please see the man page for operf.
Using default event: CPU_CLK_UNHALTED:100000:0:1:1
Using 2.6+ OProfile kernel interface.
Reading module info.
Failed to open profile device: Device or resource busy
Couldn't start oprofiled.
Check the log file "/var/lib/oprofile/samples/oprofiled.log" and kernel syslog

Anyone familiar with Oprofile will notice I'm using the proper sequence of commands to invoke the service. This comes directly from Fedora documentation . Kernel debug information was also installed to generate the appropriate vmlinux file. But even after passing the location of this file to oprofile, nothing chaged:

$ sudo opcontrol --setup --vmlinux=/usr/lib/debug/lib/modules/3.12.11-201.fc19.x86_64/vmlinux
$ sudo opcontrol --start
ATTENTION: Use of opcontrol is discouraged.  Please see the man page for operf.
Using default event: CPU_CLK_UNHALTED:100000:0:1:1
Using 2.6+ OProfile kernel interface.
Reading module info.
Failed to open profile device: Device or resource busy
Couldn't start oprofiled.
Check the log file "/var/lib/oprofile/samples/oprofiled.log" and kernel syslog

What's more is there's no log file in the specified location. I've tried several other solutions, including re-installation, deleting the daemon, and running without profiling the kernel.

• Why is the device busy when there's no oprofile processes running?
• Why is there no log file written?
• What do I change so that I can run oprofile?

Answer 1

Before running the oprofile, you should check wether your system exists watchdog. watchdog/nmi_watchdog registers with the perf subsystem which will blocking oprofile from working. You may have to stop the watchdog/NMI watchdog to free up counter 0 using the following:

echo "0" | sudo tee /proc/sys/kernel/watchdog

OR

echo "0" | sudo tee/proc/sys/kernel/nmi_watchdog