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Hi All,
This is Alecsandru from Server Scripting Languages Optimization team at Intel Corporation.
I would like to submit a request to turn-on Profile Guided Optimization or PGO as the default build option for Python (both 2.7 and 3.6), given its performance benefits on a wide variety of workloads and hardware. For instance, as shown from attached sample performance results from the Grand Unified Python Benchmark, >20% speed up was observed. In addition, we are seeing 2-9% performance boost from OpenStack/Swift where more than 60% of the codes are in Python 2.7. Our analysis indicates the performance gain was mainly due to reduction of icache misses and CPU front-end stalls.
Attached is the Makefile patches that modify the all build target and adds a new one called "disable-profile-opt". We built and tested this patch for Python 2.7 and 3.6 on our Linux machines (CentOS 7/Ubuntu Server 14.04, Intel Xeon Haswell/Broadwell with 18/8 cores). We use "regrtest" suite for training as it provides the best performance improvement. Some of the test programs in the suite may fail which leads to build fail. One solution is to disable the specific failed test using the "-x " flag (as shown in the patch)
Steps to apply the patch: 
1. hg clone https://hg.python.org/cpython cpython 
2. cd cpython 
3. hg update 2.7 (needed for 2.7 only) 
4. Copy *.patch to the current directory 
5. patch < python2.7-pgo.patch (or patch < python3.6-pgo.patch)
6. ./configure 
7. make
To disable PGO
7b. make disable-profile-opt
In the following, please find our sample performance results from latest XEON machine, XEON Broadwell EP. 
Hardware (HW): Intel XEON (Broadwell) 8 Cores
BIOS settings: Intel Turbo Boost Technology: false
 Hyper-Threading: false
 
Operating System: Ubuntu 14.04.3 LTS trusty
OS configuration: CPU freq set at fixed: 2.6GHz by
 echo 2600000 > /sys/devices/system/cpu/cpu*/cpufreq/scaling_min_freq
 echo 2600000 > /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
 Address Space Layout Randomization (ASLR) disabled (to reduce run to run variation) by
 echo 0 > /proc/sys/kernel/randomize_va_space
 
GCC version: gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04)
Benchmark: Grand Unified Python Benchmark (GUPB)
 GUPB Source: https://hg.python.org/benchmarks/ 
Python2.7 results:
 Python source: hg clone https://hg.python.org/cpython cpython
 Python Source: hg update 2.7
 hg id: 0511b1165bb6 (2.7)
 hg id -r 'ancestors(.) and tag()': 15c95b7d81dc (2.7) v2.7.10
 hg --debug id -i: 0511b1165bb6cf40ada0768a7efc7ba89316f6a5
 
 Benchmarks Speedup(%)
 simple_logging 20
 raytrace 20
 silent_logging 19
 richards 19
 chaos 16
 formatted_logging 16
 json_dump 15
 hexiom2 13
 pidigits 12
 slowunpickle 12
 django_v2 12
 unpack_sequence 11
 float 11
 mako 11
 slowpickle 11
 fastpickle 11
 django 11
 go 10
 json_dump_v2 10
 pathlib 10
 regex_compile 10
 pybench 9.9
 etree_process 9
 regex_v8 8
 bzr_startup 8
 2to3 8
 slowspitfire 8
 telco 8
 pickle_list 8
 fannkuch 8
 etree_iterparse 8
 nqueens 8
 mako_v2 8
 etree_generate 8
 call_method_slots 7
 html5lib_warmup 7
 html5lib 7
 nbody 7
 spectral_norm 7
 spambayes 7
 fastunpickle 6
 meteor_contest 6
 chameleon 6
 rietveld 6
 tornado_http 5
 unpickle_list 5
 pickle_dict 4
 regex_effbot 3
 normal_startup 3
 startup_nosite 3
 etree_parse 2
 call_method_unknown 2
 call_simple 1
 json_load 1
 call_method 1
Python3.6 results
 Python source: hg clone https://hg.python.org/cpython cpython 
 hg id: 96d016f78726 tip
 hg id -r 'ancestors(.) and tag()': 1a58b1227501 (3.5) v3.5.0rc1
 hg --debug id -i: 96d016f78726afbf66d396f084b291ea43792af1
 
 Benchmark Speedup(%)
 fastunpickle 22.94
 fastpickle 21.67
 json_load 17.64
 simple_logging 17.49
 meteor_contest 16.67
 formatted_logging 15.33
 etree_process 14.61
 raytrace 13.57
 etree_generate 13.56
 chaos 12.09
 hexiom2 12
 nbody 11.88
 json_dump_v2 11.24
 richards 11.02
 nqueens 10.96
 fannkuch 10.79
 go 10.77
 float 10.26
 regex_compile 9.8
 silent_logging 9.63
 pidigits 9.58
 etree_iterparse 9.48
 2to3 8.44
 regex_v8 8.09
 regex_effbot 7.88
 call_simple 7.63
 tornado_http 7.38
 etree_parse 4.92
 spectral_norm 4.72
 normal_startup 4.39
 telco 3.88
 startup_nosite 3.7
 call_method 3.63
 unpack_sequence 3.6
 call_method_slots 2.91
 call_method_unknown 2.59
 iterative_count 0.45
 threaded_count -2.79
Thank you,
Alecsandru