Re: Enable/disable hardware prefetcher via Oprofile
William Cohen <[email protected]>
| Newsgroups | gmane.linux.oprofile |
|---|---|
| Message-ID | <[email protected]> |
On 06/03/2015 08:31 AM, Mahmood N wrote: > Hello, > I have read that it is possible to control the AMD's hardware prefetcher via Oprofile. Is that correct? If so, please let me know where should I start to read? > > The machine is Opteron 6274 (famliy 15h) and it seems that the MSR register is named MSRC001 1022 > > > Regards, > Mahmood Hi Mahmood, OProfile only records sampling data; it doesn't control the hardware prefetcher. You could could use the oprofile data to help determine what section of code the prefetch hardware should be enabled and disabled for. >From user-space you can access the msr register through /dev/cpu/*/msr, but the changes only affect a particular processor. You will also need to set the affinity of processors so they are not migrated to other processors. -Will ------------------------------------------------------------------------------