On Sun, Mar 15, 2020 at 01:05:10PM +0800, Xiaoyao Li wrote: > In a context switch from a task that is detecting split locks > to one that is not (or vice versa) we need to update the TEST_CTRL > MSR. Currently this is done with the common sequence: > read the MSR > flip the bit > write the MSR > in order to avoid changing the value of any reserved bits in the MSR. > > Cache the value of the TEST_CTRL MSR when we read it during initialization > so we can avoid an expensive RDMSR instruction during context switch. > > Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Originally-by: Tony Luck <tony.luck@xxxxxxxxx> > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> Is it bad form to Ack/Review patches originally by oneself? Whatever: Acked-by: Tony Luck <tony.luck@xxxxxxxxx>
