[Piglit] [Patch v5 1/4] framework/dmesg: Adds a new module for dmesg
Ken Phillis Jr
kphillisjr at gmail.com
Tue Feb 4 10:40:26 PST 2014
I believe that this should be tested for permissions checks. I
honestly do not believe that it would be a good idea to always clear
the ringbuffer seeing as how on some systems this command requires
root level permissions.
On Tue, Feb 4, 2014 at 12:28 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> On Tue, Feb 4, 2014 at 1:12 PM, Dylan Baker <baker.dylan.c at gmail.com> wrote:
>> On Tuesday, February 04, 2014 12:43:42 PM Ilia Mirkin wrote:
>>> On Tue, Feb 4, 2014 at 12:35 PM, Dylan Baker <baker.dylan.c at gmail.com>
>> wrote:
>>> > This modules implements two classes and a helper function. The two
>>> > classes are both dmesg wrapper classes, one, PosixDmesg is used on posix
>>> > systems when requested to actually do checks on dmesg. The second class,
>>> > DummyDmesg, is used to reduce code complexity by providing dummy
>>> > versions of the methods in PosixDmesg. This means that we don't need
>>> > separate code paths for Posix systems wanting to check dmesg, Posix
>>> > systems not wanting to check dmesg, and non-posix systems which lack
>>> > dmesg.
>>> >
>>> > Beyond reducing complexity this module also gives better isolation,
>>> > dmesg is only used in Test.execute(), no where else. Additional classes
>>> > don't need to worry about dmesg that way, it's just available.
>>> >
>>> > v2: - Remove unnecessary assert from PosixDmesg.update_result()
>>> >
>>> > - simplify replace helper in PoixDmesg.update_result()
>>> > - replace try/except with if check
>>> > - Change PosixDmesg.update_dmesg() to work even if dmesg 'wraps'
>>> >
>>> > v3: - Try/Except assignment of PosixDmesg._last_message in update_dmesg()
>>> >
>>> > - Set the dmesg levels the same as the previous implementation
>>> > - Change PosixDmesg into LinuxDmesg and enforce that dmesg has
>>> >
>>> > timestamps
>>> >
>>> > v4: - Add check in LinuxDmesg.__init__ to ensure there is something in
>>> >
>>> > dmesg before doing the timestamp check. This should make problems
>>> > clearer
>>> >
>>> > - Refactor some code in LinuxDmesg.update_result()
>>> >
>>> > v5: - Replace exception with warning.
>>> >
>>> > - add break to loop in dmesg.update_dmesg
>>> >
>>> > Signed-off-by: Dylan Baker <baker.dylan.c at gmail.com>
>>> > ---
>>> >
>>> > framework/dmesg.py | 175
>>> > +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed,
>>> > 175 insertions(+)
>>> > create mode 100644 framework/dmesg.py
>>> >
>>> > diff --git a/framework/dmesg.py b/framework/dmesg.py
>>> > new file mode 100644
>>> > index 0000000..feb05ad
>>> > --- /dev/null
>>> > +++ b/framework/dmesg.py
>>> > @@ -0,0 +1,175 @@
>>> > +# Copyright (c) 2013-2014 Intel Corporation
>>> > +#
>>> > +# Permission is hereby granted, free of charge, to any person obtaining a
>>> > +# copy of this software and associated documentation files (the
>>> > "Software"), +# to deal in the Software without restriction, including
>>> > without limitation +# the rights to use, copy, modify, merge, publish,
>>> > distribute, sublicense, +# and/or sell copies of the Software, and to
>>> > permit persons to whom the +# Software is furnished to do so, subject to
>>> > the following conditions: +#
>>> > +# The above copyright notice and this permission notice (including the
>>> > next +# paragraph) shall be included in all copies or substantial
>>> > portions of the +# Software.
>>> > +#
>>> > +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
>>> > OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>> > MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
>>> > IN NO EVENT SHALL +# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
>>> > CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
>>> > TORT OR OTHERWISE, ARISING +# FROM, OUT OF OR IN CONNECTION WITH THE
>>> > SOFTWARE OR THE USE OR OTHER DEALINGS +# IN THE SOFTWARE.
>>> > +
>>> > +""" Module implementing classes for reading posix dmesg
>>> > +
>>> > +Currently this module only has the default DummyDmesg, and a LinuxDmesg.
>>> > +The method used on Linux requires that timetamps are enabled, and no
>>> > other
>>> > +posix system has timestamps.
>>> > +
>>> > +On OSX and *BSD one would likely want to implement a system that reads
>>> > the
>>> > +sysloger, since timestamps can be added by the sysloger, and are not
>>> > inserted +by dmesg.
>>> > +
>>> > +"""
>>> > +
>>> > +import re
>>> > +import sys
>>> > +import subprocess
>>> > +import warnings
>>> > +
>>> > +__all__ = ['LinuxDmesg', 'DummyDmesg', 'get_dmesg']
>>> > +
>>> > +
>>> > +class LinuxDmesg(object):
>>> > + """ Read dmesg on posix systems
>>> > +
>>> > + This reads the dmesg ring buffer, stores the contents of the buffer,
>>> > and + then compares it whenever called, returning the difference
>>> > between the + calls. It requires timestamps to be enabled.
>>> > +
>>> > + """
>>> > + DMESG_COMMAND = ['dmesg', '--level',
>>> > 'emerg,alert,crit,err,warn,notice'] +
>>> > + def __init__(self):
>>> > + """ Create a dmesg instance """
>>> > + self._last_message = None
>>> > + self._new_messages = []
>>> > +
>>> > + # Populate self.dmesg initially, otherwise the first test will
>>> > always + # be full of dmesg crud.
>>> > + self.update_dmesg()
>>> > +
>>> > + if not self._last_message:
>>> > + # We need to ensure that there is something in dmesg to check
>>> > + # timestamps.
>>> > + warnings.warn("Cannot check dmesg for timestamp support. If
>>> > you " + "do not have timestamps enabled in your
>>> > kernel you " + "get incomplete dmesg captures",
>>> > RuntimeWarning) + elif not re.match(r'\[\s*\d+\.\d+\]',
>>> > self._last_message): + # Do an initial check to ensure that
>>> > dmesg has timestamps, we need + # timestamps to work
>>> > correctly. A proper linux dmesg timestamp + # looks like this:
>>> > [ 0.00000]
>>> > + raise DmesgError(
>>> > + "Your kernel does not seem to support timestamps, which "
>>> > + "are required by the --dmesg option")
>>>
>>> Consider also making this a warning.
>>>
>>> Either way, Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>
>>>
>>> > +
>>> > + def update_result(self, result):
>>> > + """ Takes a TestResult object and updates it with dmesg statuses
>>> > +
>>> > + If dmesg is enabled, and if dmesg has been updated, then replace
>>> > pass + with dmesg-warn and warn and fail with dmesg-fail. If dmesg
>>> > has not + been updated, it will return the original result passed
>>> > in. +
>>> > + Arguments:
>>> > + result -- A TestResult instance
>>> > +
>>> > + """
>>> > +
>>> > + def replace(res):
>>> > + """ helper to replace statuses with the new dmesg status
>>> > +
>>> > + Replaces pass with dmesg-warn, and warn and fail with
>>> > dmesg-fail, + otherwise returns the input
>>> > +
>>> > + """
>>> > + return {"pass": "dmesg-warn",
>>> > + "warn": "dmesg-fail",
>>> > + "fail": "dmesg-fail"}.get(res, res)
>>> > +
>>> > + # Get a new snapshot of dmesg
>>> > + self.update_dmesg()
>>> > +
>>> > + # if update_dmesg() found new entries replace the results of the
>>> > test + # and subtests
>>> > + if self._new_messages:
>>> > + result['result'] = replace(result['result'])
>>> > +
>>> > + # Replace any subtests
>>> > + if 'subtest' in result:
>>> > + for key, value in result['subtest'].iteritems():
>>> > + result['subtest'][key] = replace(value)
>>> > +
>>> > + # Add the dmesg values to the result
>>> > + result['dmesg'] = self._new_messages
>>> > +
>>> > + return result
>>> > +
>>> > + def update_dmesg(self):
>>> > + """ Call dmesg using subprocess.check_output
>>> > +
>>> > + Get the contents of dmesg, then calculate new messages, finally
>>> > set + self.dmesg equal to the just read contents of dmesg.
>>> > +
>>> > + """
>>> > + dmesg =
>>> > subprocess.check_output(self.DMESG_COMMAND).strip().splitlines() +
>>> > + # Find all new entries, do this by slicing the list of dmesg to
>>> > only + # returns elements after the last element stored. If there
>>> > are not + # matches a value error is raised, that means all of
>>> > dmesg is new + l = 0
>>> > + for index, item in enumerate(reversed(dmesg)):
>>> > + if item == self._last_message:
>>> > + l = len(dmesg) - index # don't include the matched
>>> > element + break
>>> > + self._new_messages = dmesg[l:]
>>> > +
>>> > + # Attempt to store the last element of dmesg, unless there was no
>>> > dmesg + self._last_message = dmesg[-1] if dmesg else None
>>> > +
>>> > +
>>> > +class DummyDmesg(object):
>>> > + """ An dummy class for dmesg on non unix-like systems
>>> > +
>>> > + This implements a dummy version of the LinuxDmesg, and can be used
>>> > anytime + it is not desirable to actually read dmesg, such as
>>> > non-posix systems, or + when the contents of dmesg don't matter.
>>> > +
>>> > + """
>>> > + DMESG_COMMAND = []
>>> > +
>>> > + def __init__(self):
>>> > + pass
>>> > +
>>> > + def update_dmesg(self):
>>> > + """ Dummy version of update_dmesg """
>>> > + pass
>>> > +
>>> > + def update_result(self, result):
>>> > + """ Dummy version of update_result """
>>> > + return result
>>> > +
>>> > +
>>> > +class DmesgError(EnvironmentError):
>>> > + pass
>>> > +
>>> > +
>>> > +def get_dmesg(not_dummy=True):
>>> > + """ Return a Dmesg type instance
>>> > +
>>> > + Normally this does a system check, and returns the type that proper
>>> > for + your system. However, if Dummy is True then it will always
>>> > return a + DummyDmesg instance.
>>> > +
>>> > + """
>>> > + if sys.platform.startswith('linux') and not_dummy:
>>> > + return LinuxDmesg()
>>> > + return DummyDmesg()
>>> > --
>>> > 1.8.5.3
>>> >
>>> > _______________________________________________
>>> > Piglit mailing list
>>> > Piglit at lists.freedesktop.org
>>> > http://lists.freedesktop.org/mailman/listinfo/piglit
>>
>> Is that review for the series?
>
> It's a review for this patch. I believe I also reviewed 3/4 and 4/4
> earlier on (and those reviews should still stand). 2/4 uses some fancy
> testing framework I'm not familiar with, so I haven't looked at it.
> But the impact is also low, so probably fine to commit unreviewed?
> Dunno what the policy is.
> _______________________________________________
> Piglit mailing list
> Piglit at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/piglit
More information about the Piglit
mailing list