PlaintextMVC benchmark is slow on arm64 #60166
Description
Plaintext-PlaintextMVC benchmark should benefit a lot from PGO (namely, from guarded devirtualizations and inlining) and it does benefit from it on all x64 platforms (Linux, Windows, Intel, Amd, etc) - up to +40% more RPS. Unfortunately, it's not the case for arm64 where there is no difference between DynamicPGO and Default. Moreover, the benchmark is 7-8x times slower on arm64 in comparison with x64-dynamicpgo (while I'd expect it to be 1.5-2x slower only).
It looks to me that on arm64 it's bound to JIT_New:
while on x64 it looks like this:
Namely, this call-site ("drilled") (https://github.com/dotnet/aspnetcore/blob/a0b950fc51c43289ab3c6dbea15926d32f3556cc/src/Mvc/Mvc.Core/src/Routing/ControllerRequestDelegateFactory.cs#L68-L101):
Arm64:
same call-site on x64:
Flamegraph for arm64 (two JIT_New are highlighted) for the first th:
x64:
Does it ring a bell to anyone (e.g. JIT_NewS_MP_FastPortable is not used, some gc feature is not implemented for arm64, some allocation tracker/profiler is enabled, etc.)?
/cc @dotnet/jit-contrib @Maoni0 @jkotas @davidwrighton
I can re-run the benchmark with any modifications in jit/vm/gc you suggest.
Steps to get the native traces:
Arm64-Linux:
crank --config https://raw.githubusercontent.com/aspnet/Benchmarks/main/scenarios/plaintext.benchmarks.yml --scenario mvc --profile aspnet-citrine-arm --application.collect true --application.collectStartup false --application.options.collectCounters false --application.dotnetTrace false --application.framework net6.0 --application.environmentVariables DOTNET_TieredPGO=1 --application.environmentVariables DOTNET_TC_QuickJitForLoops=1 --application.environmentVariables DOTNET_ReadyToRun=0
x64-Linux:
crank --config https://raw.githubusercontent.com/aspnet/Benchmarks/main/scenarios/plaintext.benchmarks.yml --scenario mvc --profile aspnet-citrine-lin --application.collect true --application.collectStartup false --application.options.collectCounters false --application.dotnetTrace false --application.framework net6.0 --application.environmentVariables DOTNET_TieredPGO=1 --application.environmentVariables DOTNET_TC_QuickJitForLoops=1 --application.environmentVariables DOTNET_ReadyToRun=0
Powerbi link: https://aka.ms/aspnet/benchmarks (open "PGO" page there)