Parse the data source field of SPE record

[adamliyi]

On Altra, the SPE record contains Data-Source field:

.  00000113:  49 00                                           LD GP-REG
.  00000115:  52 1e 03                                        EV RETIRED L1D-ACCESS L1D-REFILL TLB-ACCESS LLC-ACCESS LLC-REFILL
.  00000118:  99 51 01                                        LAT 337 ISSUE
.  0000011b:  98 f5 01                                        LAT 501 TOT
.  0000011e:  b2 50 9e d7 f1 3e 40 ff 00                      VA 0xff403ef1d79e50
.  00000127:  9a 01 00                                        LAT 1 XLAT
.  0000012a:  b3 50 9e d7 71 3f 40 00 80                      PA 0x403f71d79e50 ns=1
.  00000133:  43 0c                                           DATA-SOURCE 12
.  00000135:  00 00                                           PAD
.  00000137:  71 b3 9a e9 bd 3e 07 00 00                      TS 7966055570099
.  00000140:  b0 88 b6 cb 8f 22 d4 ff c0                      PC 0xffd4228fcbb688 el2 ns=1
.  00000149:  00 00 00 00 00 00 00 00 00 00                   PAD

We need to parse the 'Data-Source' field and display in 'perf mem report'.

[adamliyi]

Examples:

1. record SPE perf.data

perf record -C 1 -d -e arm_spe_0/ts_enable=1,pa_enable=1,load_filter=1,store_filter=1,min_latency=1/ -- sleep 10

2. check raw SPE record with perf script -D, search DATA-SOURCE
3. Add a new data_src field to sort perf report result.
   perf mem report -p --sort data_src

[adamliyi]

Initial patch here (not widely reviewed): #131
With this patch, we can sort SPE samples with 'DATA-SOURCE' field:

$ perf mem record -p -- numactl -m 0 ./false_sharing.exe 1
135 mticks, reader_thd (thread 1), on node 1 (cpu 102).
149 mticks, lock_th (thread 0), on node 0 (cpu 0).
[ perf record: Woken up 19 times to write data ]
[ perf record: Captured and wrote 36.170 MB perf.data ]

$ perf mem report -p --sort hw_dsrc --stdio
# Samples: 592K of event 'memory'
# Total weight : 592133
# Sort order   : hw_dsrc
#
# Overhead       Samples  Hardware Data Source
# ........  ............  ....................
#
    99.58%        589636  L1 data cache
     0.41%          2403  Remote
     0.01%            74  L2 cache
     0.00%            16  System cache
     0.00%             2  DRAM
     0.00%             1  Peer CPU
     0.00%             1  Peer Cluster