[issue11051] system calls per import

[Antoine Pitrou]

New submission from Antoine Pitrou <pitrou at free.fr>:

Here are the system calls when importing a single pure Python module:

stat("/home/antoine/py3k/py3k/Lib/copyreg", 0x7fff1ed1f740) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyreg.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyregmodule.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyreg.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyregmodule.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyreg.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyregmodule.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/copyreg.py", O_RDONLY) = 5
fstat(5, {st_mode=S_IFREG|0664, st_size=6633, ...}) = 0
open("/home/antoine/py3k/py3k/Lib/__pycache__/copyreg.cpython-32.pyc", O_RDONLY) = 6
fstat(6, {st_mode=S_IFREG|0664, st_size=5595, ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f28e6381000
read(6, "l\f\r\n\0\24\212Hc\0\0\0\0\0\0\0\0\0\0\0\0\f\0\0\0@\0\0\0s\307\0"..., 4096) = 4096
fstat(6, {st_mode=S_IFREG|0664, st_size=5595, ...}) = 0


This is per possible directory, which means that it can be repeated for each dir on sys.path:

stat("readline", 0x7fff1ed28760)        = -1 ENOENT (No such file or directory)
open("readline.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("readlinemodule.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("readline.abi3.so", O_RDONLY)      = -1 ENOENT (No such file or directory)
open("readlinemodule.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("readline.so", O_RDONLY)           = -1 ENOENT (No such file or directory)
open("readlinemodule.so", O_RDONLY)     = -1 ENOENT (No such file or directory)
open("readline.py", O_RDONLY)           = -1 ENOENT (No such file or directory)
open("readline.pyc", O_RDONLY)          = -1 ENOENT (No such file or directory)
stat("/home/antoine/py3k/py3k/Lib/readline", 0x7fff1ed28760) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readline.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readlinemodule.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readline.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readlinemodule.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readline.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readlinemodule.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readline.py", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/readline.pyc", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/home/antoine/py3k/py3k/Lib/plat-linux2", {st_mode=S_IFDIR|0775, st_size=4096, ...}) = 0
stat("/home/antoine/py3k/py3k/Lib/plat-linux2", {st_mode=S_IFDIR|0775, st_size=4096, ...}) = 0
stat("/home/antoine/py3k/py3k/Lib/plat-linux2/readline", 0x7fff1ed28760) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readline.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readlinemodule.cpython-32m.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readline.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readlinemodule.abi3.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readline.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readlinemodule.so", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readline.py", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/Lib/plat-linux2/readline.pyc", O_RDONLY) = -1 ENOENT (No such file or directory)
stat("/home/antoine/py3k/py3k/build/lib.linux-x86_64-3.2", {st_mode=S_IFDIR|0775, st_size=4096, ...}) = 0
stat("/home/antoine/py3k/py3k/build/lib.linux-x86_64-3.2", {st_mode=S_IFDIR|0775, st_size=4096, ...}) = 0
stat("/home/antoine/py3k/py3k/build/lib.linux-x86_64-3.2/readline", 0x7fff1ed28760) = -1 ENOENT (No such file or directory)
open("/home/antoine/py3k/py3k/build/lib.linux-x86_64-3.2/readline.cpython-32m.so", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0775, st_size=59970, ...}) = 0
futex(0x7f28e605e0ec, FUTEX_WAKE_PRIVATE, 2147483647) = 0
open("/home/antoine/py3k/py3k/build/lib.linux-x86_64-3.2/readline.cpython-32m.so", O_RDONLY) = 4


Something has gone out of control here. Why do we need to check so many alternative locations?

----------
components: Interpreter Core
messages: 127359
nosy: barry, loewis, pitrou
priority: normal
severity: normal
status: open
title: system calls per import
type: performance
versions: Python 3.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue11051>
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