Unsupported CPU: 0x506f0 Intel(R) Atom(TM) C3955

$ bin/rr record cat
[FATAL /home/namibj/src/rr/src/PerfCounters.cc:234:get_cpu_microarch()] Intel CPU type 0x506f0 unknown

This seems to be a CPU too obscure to have crossed your path already.
See:

$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 95
model name      : Intel(R) Atom(TM) CPU C3955 @ 2.10GHz
stepping        : 1
microcode       : 0x1
cpu MHz         : 2100.000
cache size      : 4096 KB
physical id     : 0
siblings        : 1
core id         : 0
cpu cores       : 1
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 13
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl pni pclmulqdq vmx ssse3 cx16 sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave rdrand hypervisor lahf_lm 3dnowprefetch ibrs ibpb kaiser tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust smep erms mpx rdseed smap clflushopt xsaveopt xsavec xgetbv1 xsaves arat
bugs            : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass
bogomips        : 4200.00
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

I'm using some of them at Scaleway, due to the low price and relative lack of fuss.

Start with src/PerfCounters.cc at get_cpu_microarch(), where bin/rr record cat reports the unknown Intel CPU type 0x506f0. Review the CPU identification path and existing Intel CPU cases, then run bin/rr record cat on the reported Atom C3955 or an equivalent system. Done means recording no longer fails with the unsupported-CPU error.