2018-02-24 8:24 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>: > On 11/02/2018 09:42, Wanpeng Li wrote: >> Cc chandu, >> 2018-01-08 22:53 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>: >>> On 08/01/2018 10:57, Jan Kiszka wrote: >>>>>> Shouldn't this be done on AMD as well, or is the answer "microcode >>>>>> update" there? >>>>>> >>>>>> Jan >>>>> Paolo added it, already in linus tree Linux 4.15-rc7 >>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0cb5b30698fdc8f6b4646012e3acb4ddce430788 >>>> Thanks, I didn't noticed this. >>> >>> Yeah, they were posted in a separate thread. (Actually Ashok Raj's >>> patch was mine, :) but I went with Jim's VMX part and attribution >>> because he actually tested it with Google's reproducer). >> >> We cooperate with AMD guys to test the Scrub hardware GPRs against >> latest AMD EPYC, we observe the performance of Redis drop ~11% in the >> guest (Centos 7.4, 3.10.0-693). > > So there are no updates installed in the guest (-693 is the version that > was released with 7.4)? Or is it the latest CentOS kernel using IBRS? Chandu, Please add your inputs here. Regards, Wanpeng Li > > I don't think scrubbing should be particularly expensive. However, > filling the RSB can cost over 50 clock cycles. > > Thanks, > > Paolo > >> redis(redis_version:3.2.10) >> >> Redis command line: >> >> redis-server > /dev/null 2>&1 & >> redis-benchmark -t ping,set,get -d 128 -c 100 -r 1000000 -n 10000000 -q -P 20 >> redis-benchmark -t ping,set,get -d 1024 -c 100 -r 1000000 -n 10000000 -q -P 20 >> redis-benchmark -t ping,set,get -d 2048 -c 100 -r 1000000 -n 10000000 -q -P 20 >> >> Regards, >> Wanpeng Li >> >
