On Fri, 30 Mar 2018, Dave Hansen wrote: > On 03/30/2018 05:17 AM, Ingo Molnar wrote: > > BTW., the expectation on !PCID Intel hardware would be for global pages to help > > even more than the 0.6% and 1.7% you measured on PCID hardware: PCID already > > _reduces_ the cost of TLB flushes - so if there's not even PCID then global pages > > should help even more. > > > > In theory at least. Would still be nice to measure it. > > I did the lseek test on a modern, non-PCID system: > > No Global pages (baseline): 6077741 lseeks/sec > 94 Global pages (this set): 8433111 lseeks/sec > +2355370 lseeks/sec (+38.8%) That's all kernel text, right? What's the result for the case where global is only set for all user/kernel shared pages? Thanks, tglx
