Following the results of the previous comparison, i've used Jorge's profiling example on the 'call_method' bench for trusty stock, no LTO, no PGO and Xenial stock, no PGO and no LTO. Here are the results. Notice the difference between Trusty Stock & Trusty nopgo, as opposed to the execution profiles of the other tests. Trusty Stock ============ callgrind_annotate: Profiled target: /home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python /home/ubuntu/venv/cpython2.7-d0d7712d4e1d/li b/python2.7/site-packages/performance/benchmarks/bm_call_method.py --worker --pipe 4 --worker-task=0 --samples 3 -- warmups 1 --loops 1 --min-time 0.1 (PID 25150, part 1) 4,918,198,605 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 1,180,507,700 ???:0x00000000005368f0 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 1,109,707,368 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 823,065,734 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 552,755,137 ???:0x00000000004a5c90 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 525,836,692 ???:0x00000000004bedf0 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 12,732,711 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 6,120,934 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 4,700,333 ???:0x00000000004bc0e0 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 4,647,564 ???:0x00000000004afe90'2 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 3,724,240 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 3,526,112 ???:PyDict_SetItem [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 3,407,575 ???:0x0000000000571fd0 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 3,304,198 ???:PyObject_Hash [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 3,055,436 ???:0x00000000005495a0 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] 2,796,306 ???:0x0000000000535070 [/home/ubuntu/venv/cpython2.7-d0d7712d4e1d/bin/python2.7] Trusty nopgo: ============= Profiled target: /home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python /home/ubuntu/venv/cpython2.7-d217262e7ee7/li b/python2.7/site-packages/performance/benchmarks/bm_call_method.py --worker --pipe 4 --worker-task=0 --samples 3 -- warmups 1 --loops 1 --min-time 0.1 (PID 28073, part 1) 5,362,602,828 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 1,250,195,637 ???:0x0000000000585e90 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 890,479,191 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 836,574,419 ???:PyObject_GenericGetAttr [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 552,808,267 ???:0x000000000049ef00 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 539,318,922 ???:0x0000000000493710 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 488,401,927 ???:_PyType_Lookup [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 258,028,053 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 12,247,026 ???:0x00000000005937f0 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 11,727,983 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 6,409,083 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 4,948,165 ???:PyObject_Malloc [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 4,746,403 ???:0x00000000004f7b70'2 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 4,525,638 ???:PyNode_AddChild [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 4,429,698 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 3,582,953 ???:0x000000000041aff0 [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] 3,240,230 ???:PyObject_Hash [/home/ubuntu/venv/cpython2.7-d217262e7ee7/bin/python2.7] Trusty nolto: ============= Profiled target: /home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7 /home/ubuntu/venv/cpython2.7-d8da6ef977cc /lib/python2.7/site-packages/performance/benchmarks/bm_call_method.py --worker --pipe 4 --worker-task=0 --samples 3 --warmups 1 --loops 1 --min-time 0.1 (PID 27353, part 1) 4,930,764,066 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 1,059,123,292 ???:0x0000000000486370 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 879,185,389 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 823,049,135 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 552,712,907 ???:0x0000000000477410 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 539,326,714 ???:PyMethod_New [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 472,694,320 ???:_PyType_Lookup [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 148,897,549 ???:PyObject_GC_UnTrack [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 40,448,799 ???:0x00000000004877d0 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 10,899,345 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 10,348,722 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 4,662,730 ???:0x00000000004cd110 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 4,637,942 ???:0x000000000050b720'2 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 4,432,451 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 4,094,020 ???:PyDict_SetItem [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 3,629,015 ???:PyNode_AddChild [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 3,408,211 ???:0x00000000004a2260 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 3,232,715 ???:PyObject_Malloc [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 3,206,499 ???:PyObject_Hash [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] 3,055,436 ???:0x000000000050b610 [/home/ubuntu/venv/cpython2.7-d8da6ef977cc/bin/python2.7] Xenial Stock ============ Profiled target: /home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python /home/ubuntu/venv/cpython2.7-abc0c129a9a8/li b/python2.7/site-packages/performance/benchmarks/bm_call_method.py --worker --pipe 4 --worker-task=0 --samples 3 -- warmups 1 --loops 1 --min-time 0.1 (PID 28373, part 1) 5,293,380,177 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 1,058,376,436 ???:0x00000000004d9030 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 850,012,013 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 823,053,334 ???:_PyObject_GenericGetAttrWithDict [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 525,847,184 ???:PyMethod_New [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 471,794,110 ???:0x00000000004e1030 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 461,203,120 ???:_PyType_Lookup [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 312,611,371 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 148,905,231 ???:PyObject_GC_UnTrack [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 40,444,971 ???:0x00000000004e09c0 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 12,120,701 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 10,987,593 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 6,574,452 ???:PyObject_Malloc [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 5,006,318 ???:0x00000000004bdc60'2 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 4,842,496 ???:PyDict_SetItem [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 4,519,155 ???:PyDict_Next [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,835,459 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,270,809 ???:PyObject_Hash [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,257,249 ???:PyNode_AddChild [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] Xenial nopgo: ============= Profiled target: /home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python /home/ubuntu/venv/cpython2.7-abc0c129a9a8/li b/python2.7/site-packages/performance/benchmarks/bm_call_method.py --worker --pipe 4 --worker-task=0 --samples 3 -- warmups 1 --loops 1 --min-time 0.1 (PID 31025, part 1) 5,293,380,790 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 1,058,376,436 ???:0x00000000004d9030 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 850,012,013 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 823,053,388 ???:_PyObject_GenericGetAttrWithDict [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 525,847,184 ???:PyMethod_New [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 471,794,110 ???:0x00000000004e1030 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 461,203,154 ???:_PyType_Lookup [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 312,611,394 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 148,905,242 ???:PyObject_GC_UnTrack [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 40,444,971 ???:0x00000000004e09c0 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 12,120,701 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 10,987,593 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 6,569,654 ???:PyObject_Malloc [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 5,006,318 ???:0x00000000004bdc60'2 [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 4,842,666 ???:PyDict_SetItem [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 4,519,155 ???:PyDict_Next [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,835,456 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,270,809 ???:PyObject_Hash [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] 3,257,249 ???:PyNode_AddChild [/home/ubuntu/venv/cpython2.7-abc0c129a9a8/bin/python2] Xenial nolto ============ 4,638,372,768 ???:PyEval_EvalFrameEx'2 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 1,032,105,069 ???:0x00000000004baed0 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 930,988,654 ???:_PyObject_GenericGetAttrWithDict [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 836,521,421 ???:PyFrame_New [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 539,330,714 ???:PyMethod_New [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 471,820,360 ???:0x00000000004ab110 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 459,027,697 ???:_PyType_Lookup [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 231,463,205 ???:PyObject_GetAttr [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 148,905,033 ???:PyObject_GC_UnTrack [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 40,447,959 ???:0x00000000004bb9c0 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 26,987,922 ???:PyObject_GenericGetAttr [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 10,987,547 ???:PyParser_AddToken [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 10,817,485 ???:0x00000000004d5100 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 6,371,045 ???:PyDict_GetItem [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 4,810,558 ???:0x0000000000531b20'2 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 4,434,281 ???:0x00000000004f4f70 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 4,103,768 ???:PyObject_Free [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 3,779,149 ???:0x00000000004d66a0 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 3,406,572 ???:PyDict_SetItem [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 3,363,736 ???:0x0000000000596340 [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 3,257,249 ???:PyNode_AddChild [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2] 3,245,139 ???:PyObject_Malloc [/home/ubuntu/venv/cpython2.7-67a0e317201d/bin/python2]