Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
selftests: net: py: don't default to shell=True
Overhead of using shell=True is quite significant.
Micro-benchmark of running ethtool --help shows that
non-shell run is 2x faster.
Runtime of the XDP tests also shows improvement:
this patch: 2m34s 2m21s 2m18s 2m18s
before: 2m54s 2m36s 2m34s
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250830184317.696121-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+9
-2
+9
-2
tools/testing/selftests/net/lib/py/utils.py
+9
-2
tools/testing/selftests/net/lib/py/utils.py
···
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"""
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Execute a command on local or remote host.
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+
@shell defaults to false, and class will try to split @comm into a list
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if it's a string with spaces.
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+
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Use bkg() instead to run a command in the background.
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"""
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-
def __init__(self, comm, shell=True, fail=True, ns=None, background=False,
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+
def __init__(self, comm, shell=None, fail=True, ns=None, background=False,
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host=None, timeout=5, ksft_wait=None):
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if ns:
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comm = f'ip netns exec {ns} ' + comm
···
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if host:
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self.proc = host.cmd(comm)
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else:
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+
# If user doesn't explicitly request shell try to avoid it.
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if shell is None and isinstance(comm, str) and ' ' in comm:
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comm = comm.split()
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+
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# ksft_wait lets us wait for the background process to fully start,
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# we pass an FD to the child process, and wait for it to write back.
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# Similarly term_fd tells child it's time to exit.
···
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with bkg("my_binary", ksft_wait=5):
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"""
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-
def __init__(self, comm, shell=True, fail=None, ns=None, host=None,
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+
def __init__(self, comm, shell=None, fail=None, ns=None, host=None,
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exit_wait=False, ksft_wait=None):
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super().__init__(comm, background=True,
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shell=shell, fail=fail, ns=ns, host=host,