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authorKajol Jain <kjain@linux.ibm.com>2021-02-09 12:52:34 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-02-11 15:35:36 +0300
commit82d2c16b350f72aa21ac2a6860c542aa4b43a51e (patch)
tree211576b43194d8c00ed547d6c2a7be3f1bf21740 /arch/powerpc/kernel/asm-offsets.c
parentb3abe590c80e0ba55b6fce48762232d90dbc37a5 (diff)
downloadlinux-82d2c16b350f72aa21ac2a6860c542aa4b43a51e.tar.xz
powerpc/perf: Adds support for programming of Thresholding in P10
Thresholding, a performance monitoring unit feature, can be used to identify marked instructions which take more than expected cycles between start event and end event. Threshold compare (thresh_cmp) bits are programmed in MMCRA register. In Power9, thresh_cmp bits were part of the event code. But in case of P10, thresh_cmp are not part of event code due to inclusion of MMCR3 bits. Patch here adds an option to use attr.config1 variable to be used to pass thresh_cmp value to be programmed in MMCRA register. A new ppmu flag called PPMU_HAS_ATTR_CONFIG1 has been added and this flag is used to notify the use of attr.config1 variable. Patch has extended the parameter list of 'compute_mmcr', to include power_pmu's 'flags' element and parameter list of get_constraint to include attr.config1 value. It also extend parameter list of power_check_constraints inorder to pass perf_event list. As stated by commit ef0e3b650f8d ("powerpc/perf: Fix Threshold Event Counter Multiplier width for P10"), constraint bits for thresh_cmp is also needed to be increased to 11 bits, which is handled as part of this patch. We added bit number 53 as part of constraint bits of thresh_cmp for power10 to make it an 11 bit field. Updated layout for p10: /* * Layout of constraint bits: * * 60 56 52 48 44 40 36 32 * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | * [ fab_match ] [ thresh_cmp ] [ thresh_ctl ] [ ] * | | * [ thresh_cmp bits for p10] thresh_sel -* * * 28 24 20 16 12 8 4 0 * | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | - - - - | * [ ] | [ ] | [ sample ] [ ] [6] [5] [4] [3] [2] [1] * | | | | | * BHRB IFM -* | | |*radix_scope | Count of events for each PMC. * EBB -* | | p1, p2, p3, p4, p5, p6. * L1 I/D qualifier -* | * nc - number of counters -* * * The PMC fields P1..P6, and NC, are adder fields. As we accumulate constraints * we want the low bit of each field to be added to any existing value. * * Everything else is a value field. */ Result: command#: cat /sys/devices/cpu/format/thresh_cmp config1:0-17 ex. usage: command#: perf record -I --weight -d -e cpu/event=0x67340101EC,thresh_cmp=500/ ./ebizzy -S 2 -t 1 -s 4096 1826636 records/s real 2.00 s user 2.00 s sys 0.00 s [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.038 MB perf.data (61 samples) ] Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210209095234.837356-1-kjain@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/asm-offsets.c')
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