4.19.21: perf does not work on Ryzen, OK with 4.19.20

[Sami Farin]

The same .config, BIOS, and kernel boot parameters in both kernels.

# perf top -v
           ââError:âââââââââââââââââââââââââââââââââââââââââ
           âFailed to mmap with 12 (Cannot allocate memory)â

mmap size 528384B

[    0.015080] smpboot: CPU0: AMD Ryzen 5 1600X Six-Core Processor (family: 0x17, model: 0x1, stepping: 0x1)
[    0.020092] Performance Events: Fam17h core perfctr, AMD PMU driver.
[    0.020167] ... version:                0
[    0.020226] ... bit width:              48
[    0.020284] ... generic registers:      6
[    0.020342] ... value mask:             0000ffffffffffff
[    0.020404] ... max period:             00007fffffffffff
[    0.020465] ... fixed-purpose events:   0
[    0.020522] ... event mask:             000000000000003f

[    1.307185] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40
[    1.307248] AMD-Vi: Extended features (0xf77ef22294ada):
[    1.307309]  PPR NX GT IA GA PC GA_vAPIC
[    1.307479] AMD-Vi: Lazy IO/TLB flushing enabled
[    1.308686] amd_uncore: AMD NB counters detected
[    1.308750] amd_uncore: AMD LLC counters detected
[    1.309133] perf/amd_iommu: Detected AMD IOMMU #0 (2 banks, 4 counters/bank).


MemTotal:       32915748 kB
MemFree:         7423584 kB
MemAvailable:   30061500 kB
Buffers:            1300 kB
Cached:         22917432 kB
SwapCached:            0 kB
Active:          7432916 kB
Inactive:       17190244 kB
Active(anon):    1706056 kB
Inactive(anon):   266040 kB
Active(file):    5726860 kB
Inactive(file): 16924204 kB
Unevictable:          32 kB
Mlocked:              32 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:               140 kB
Writeback:             0 kB
AnonPages:       1704432 kB
Mapped:           668832 kB
Shmem:            271724 kB
Slab:             612960 kB
SReclaimable:     448016 kB
SUnreclaim:       164944 kB
KernelStack:       14976 kB
PageTables:        55184 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    16457872 kB
Committed_AS:    8749324 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
Percpu:            10944 kB
HardwareCorrupted:     0 kB
AnonHugePages:    608256 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
Hugetlb:               0 kB
DirectMap4k:     1221876 kB
DirectMap2M:    27021312 kB
DirectMap1G:     6291456 kB


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