Messages in this thread | | | Date | Wed, 12 Jul 2017 22:20:12 -0400 (EDT) | From | Mikulas Patocka <> | Subject | Re: [tip:x86/urgent] x86/cpu: Use indirect call to measure performance in init_amd_k6() |
| |
On Wed, 12 Jul 2017, Borislav Petkov wrote:
> On Wed, Jul 12, 2017 at 06:09:57AM -0700, tip-bot for Mikulas Patocka wrote: > > Commit-ID: 429ed86b5c99b388543f6f7f6983b1230326f2bb > > Gitweb: http://git.kernel.org/tip/429ed86b5c99b388543f6f7f6983b1230326f2bb > > Author: Mikulas Patocka <mpatocka@redhat.com> > > AuthorDate: Tue, 11 Jul 2017 07:44:05 -0400 > > Committer: Ingo Molnar <mingo@kernel.org> > > CommitDate: Wed, 12 Jul 2017 10:42:32 +0200 > > > > x86/cpu: Use indirect call to measure performance in init_amd_k6() > > > > This old piece of code is supposed to measure the performance of indirect > > calls to determine if the processor is buggy or not, however the compiler > > optimizer turns it into a direct call. > > Are you booting on a real K6 or qemu?
I tested it on K6-3 and it doesn't trigger the warning, the loop with the indirect call takes 9 million cycles (it took 4 million cycles with the direct call).
I don't have the old K6 revision with the bug.
Mikulas
> -- > Regards/Gruss, > Boris. > > ECO tip #101: Trim your mails when you reply. > --
| |