From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20020830 Description of problem: # op_start /usr/bin/op_start: line 110: modprobe: command not found Couldn't load oprofile.o module go edit /usr/bin/op_start and change line 110 to have the full path to modprobe, then try again: # op_start modprobe: Can't locate module oprofile Couldn't load oprofile.o module # rpm -qa | grep kernel kernel-pcmcia-cs-3.1.31-9 kernel-source-2.4.18-14 kernel-2.4.18-17.8.0 # rpm -qa | grep oprofile oprofile-0.3-0.20020806 Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: Install RedHad su op_start Actual Results: errors see above Additional info: P4/2530
The messages "Couldn't load oprofile.o module" is misleading. On Red Hat Linux 8.0 oprofile is not built as a module; it is compiled into the kernel. The problem is caused by the conflict between the RTC driver and the OProfile driver. Both drivers are compiled into the default kernel. OProfile provided with Red Hat Linux 8.0 does not support the Pentium 4 performance monitoring hardware, so OProfile attempts to use the RTC mechanism. To use the OProfile supplied with Red Hat Linux 8.0 on Pentium 4 you will need to append the "nortc" option in /boot/grub/grub.conf for the appropriate kernel command line.
Created attachment 81565 [details] grub.conf file with "nortc" option
Gave that a try. Still doesn't work. I'm actually using LILO, if it makes any difference: image=/boot/vmlinuz-2.4.18-17.8.0 label=linux_no_rtc initrd=/boot/initrd-2.4.18-17.8.0.img read-only append="root=LABEL=/ nortc" # op_start a.out modprobe: Can't locate module oprofile Couldn't load oprofile.o module I see oprofile does not appear to be listed in /proc/devices Perhaps there is more to this puzzle?
FYI: The same error happens on a Pentium III system: [root@eddie root]# op_start modprobe: Can't locate module oprofile Couldn't load oprofile.o module
Sigh. oprofile support is _not_ compiled into the 2.4.18-18.0 kernel. I compiled a kernel with oprofile support enabled and everything works. After reading "Red Hat Linux 8.0 Release Notes" I got the impression that oprofile was enabled in the standard RedHat kernel - this is not the case, apparently.
OProfile was compiled into all the i686 kernels for the initial release of RH 8.0. The updated uniprocessors kernels do not have it compiled it. Some laptops do not deal well with the interrupts produced by oprofile due to the power management and the laptop chipset. Thus, the uniprocessors kernels are not currently built with oprofile enabled. The SMP kernels have it enabled. Install the SMP kernel to get the OProfile support in the kernel. The SMP kernel should work on uniprocessor machines.
I am experiencing the same problem on my SMP system: [root@shamir workspace]# uname -r 2.4.18-26.8.0smp [root@shamir workspace]# op_start /usr/local/bin/op_start: line 80: modprobe: command not found Couldn't load oprofile.o module I changed my grub.conf to read: "kernel /vmlinuz-2.4.18-26.8.0smp ro root=LABEL=/ nortc" and it made no difference.
Scratch my last report. I had a vestigal copy of the new Oprofile installed on my system. Once I removed it, everything was fine.