RE: [LKP] Re: [x86/mce] 1de08dccd3: will-it-scale.per_process_ops -14.1% regression

[Luck, Tony]

> Yes, that's what we suspected. And I just did another try to force the
> percpu mce structure aligned. And the regression seems to be gone (reduced
> from 14.1% to 2%), which further proved it.

I wonder whether it would be useful for bisection of performance issues
for you to change the global definition of DEFINE_PER_CPU() to make
all per CPU definitions aligned. Just like you switch compiler flags to make
all functions aligned.

-Tony