Michael Ellerman <m...@ellerman.id.au> writes: > Anju T Sudhakar <a...@linux.vnet.ibm.com> writes: > >> Add a kernel command line parameter option to disable In-Memory Collection >> (IMC) counters and add documentation. This helps in debug. > > I'd really rather we didn't. Do we *really* need this? > > We don't have command line parameters to disable any of the other ~20 > PMUs, why is this one special?
You could also do the same thing by editing the device tree before booting your kernel, we do have the facility to do that in petitboot. A recent firmware patch: https://patchwork.ozlabs.org/patch/823249/ would fix the firmware implementation where the counters were already running before the INIT/START calls, which are likely the cause of the problems that this patch is trying to work around. I propose we have the firmware do the right thing and nothing special in kernel. i.e. not to merge this. -- Stewart Smith OPAL Architect, IBM.