On 06/01/2017, 03:58 PM, Jiri Slaby wrote: > On 06/01/2017, 03:50 PM, Ingo Molnar wrote: >> That's not what I meant! The speedup comes from (hopefully) being able to >> disable >> CONFIG_FRAME_POINTER, which: > > BTW when you are mentioning this -- my measurements were with FP disabled. > > Is there any reasonably simple-to-use benchmark I could run with FP=y > and FP=n quickly?
Nevermind, I tried 10000000 stack unwindings several times and ran netperf too. Both on the same virtual machine. On these microbenchmarks, the former performs ~ 1.03 times better, the latter ~ 1.3 times. When Mel measured the difference, it was around 10 % overall using more sophisticated benchmarks. With FP=n: # time echo 10000000 > /dev/test_dwarf real 0m6.659s user 0m0.000s sys 0m6.655s # for aa in 1 0 0 0 0; do netperf -P $aa ; done MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 47819.30 87380 16384 16384 10.00 41991.01 87380 16384 16384 10.00 43607.82 87380 16384 16384 10.00 42208.44 87380 16384 16384 10.00 44383.92 With FP=y: # time echo 10000000 > /dev/test_dwarf real 0m6.869s user 0m0.000s sys 0m6.868s # for aa in 1 0 0 0 0; do netperf -P $aa ; done MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 37807.90 87380 16384 16384 10.00 32246.67 87380 16384 16384 10.00 31358.76 87380 16384 16384 10.00 32450.00 87380 16384 16384 10.00 31326.70 thanks, -- js suse labs
