experiment with CPU identification logic

Author: JBlaschke

Project.toml

@@ -4,8 +4,11 @@ authors = ["Johannes Blaschke <[email protected]>"]
 version = "0.1.0"
 
 [deps]
+AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"
+CpuId = "adafc99b-e345-5852-983c-f28acb93d879"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
+ThreadPools = "b189fb0b-2eb5-4ed4-bc0c-d34c51242431"
 
 [compat]
-CEnum = "0.4"
+CEnum = "0.4"

tmp/threads_cpuids.jl

@@ -0,0 +1,33 @@
+# threads_cpuids.jl
+using CpuId
+function cpuid_coreid()
+    eax, ebx, ecx, edx =  CpuId.cpuid(1, 0)
+    if ( (edx & (0x00000001 << 9)) == 0x00000000)
+        CPU = -1;  # no APIC on chip
+    else
+        CPU = (ebx%Int) >> 24;
+    end
+    CPU < 0 ? 0 : CPU
+end
+
+glibc_coreid() = @ccall sched_getcpu()::Cint
+
+const cpucycle_mask = (
+    (1 << (64 - leading_zeros(CpuId.cputhreads()))) - 1
+) % UInt32
+# const cpucycle_mask = 0x00000fff
+println(cpucycle_mask)
+cpucycle_coreid() = Int(cpucycle_id()[2] & cpucycle_mask)
+
+using ThreadPools
+using Base.Threads: nthreads
+
+tglibc_coreid(i::Integer) = fetch(@tspawnat i glibc_coreid());
+tcpuid_coreid(i::Integer) = fetch(@tspawnat i cpuid_coreid());
+tcpucycle_coreid(i::Integer) = fetch(@tspawnat i cpucycle_coreid());
+
+for i in 1:nthreads()
+println("Running on thread $i (glibc_coreid: $(tglibc_coreid(i)), cpuid_coreid: $(tcpuid_coreid(i)), cpucycle_coreid: $(tcpucycle_coreid(i)))")
+    # @sync @tspawnat i sum(abs2, rand()^2 + rand()^2 for i in 1:500_000_000)
+end
+