New submission from tw.bert: Preample: This is my first post to the python issue tracker, I included a fix.
This issue is probably related to http://bugs.python.org/issue11063 . The problem: After upgrading a package on AIX 7.1 x64 that started using the uuid module, we experienced serious performance issues. The culprit (found after a day of debugging) is here: File: ctypes/util.py Note: The file /sbin/ldconfig does *not* exist, so no useful information is collected here. The statement: `f = os.popen('/sbin/ldconfig -p 2>/dev/null')` To be more specific about the performace at popen(), the performance degradation happens in it's close() method. It takes 300 ms, which is unacceptable. In a larger scope, statements that took 200ms now take 1400ms (because the above is called several times. If I simply check for os.path.exists before the popen, the performance is fine again. See the included simple patch. It's a simple unix diff, we don't have git on that machine. Git can handle those diffs easily to my knowledge. More information: Small scope, culprit identified: import os, time, traceback print os.__file__ print time.clock(),'pre' f = None try: #if os.path.exists('/sbin/ldconfig'): f = os.popen('/sbin/ldconfig -p 2>/dev/null') except: print traceback.format_exc() finally: print time.clock(),'post close' if f: f.close() print time.clock(),'post finally' This takes 300ms (post finally) without the check for exists. Large scope, before patch: time python -c "import hiredis;import redis;print 'redis-py version: %s , hiredis-py version: %s' %(redis.VERSION,hiredis.__ver sion__,)" redis-py version: (2, 10, 1) , hiredis-py version: 0.1.3 real 0m1.409s user 0m0.416s sys 0m0.129s Large scope, after patch: time python -c "import hiredis;import redis;print 'redis-py version: %s , hiredis-py version: %s' %(redis.VERSION,hiredis.__ver sion__,)" redis-py version: (2, 10, 1) , hiredis-py version: 0.1.3 real 0m0.192s user 0m0.056s sys 0m0.050s ---------- components: ctypes files: patch_ctypes_util_py.diff keywords: patch messages: 221266 nosy: tw.bert priority: normal severity: normal status: open title: Performance issue (+fix) AIX ctypes.util with no /sbin/ldconfig present versions: Python 2.7 Added file: http://bugs.python.org/file35726/patch_ctypes_util_py.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue21826> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
