On 08/29/2017 10:23 AM, Pranith Kumar wrote: > This patch increases the number of entries cached in the TLB. I went > over a few architectures to see if increasing it is problematic. Only > armv6 seems to have a limitation that only 8 bits can be used for > indexing these entries. For other architectures, the number of TLB > entries is increased to a 4K-sized cache. The patch also doubles the > number of victim TLB entries. > > Some statistics collected from a build benchmark for various cache > sizes is listed below: > > | TLB bits\vTLB entires | 8 | 16 | 32 | > | 8 | 952.94(+0.0%) | 929.99(+2.4%) | 919.02(+3.6%) | > | 10 | 898.92(+5.6%) | 886.13(+7.0%) | 887.03(+6.9%) | > | 12 | 878.56(+7.8%) | 873.53(+8.3%)* | 875.34(+8.1%) | > > The best combination for this workload came out to be 12 bits for the > TLB and a 16 entry vTLB cache.
This significantly degrades performance of alpha-softmmu. It spends about 25% of all cpu time in memset. r~