[RFC, PATCH] UBUNTU: fix perf kernel version detection for multiple-flavour strings

[Tim Gardner]

On 04/21/2010 07:30 AM, Andy Whitcroft wrote:
> On Wed, Apr 21, 2010 at 07:25:58AM -0600, Tim Gardner wrote:
>> On 04/21/2010 06:42 AM, Jeremy Kerr wrote:
>>> Currently, the perf tool doesn't work for the generic-pae flavour:
>>>
>>>   $ bash -x /usr/bin/perf
>>>   ++ uname -r
>>>   + version=2.6.32-21-generic-pae
>>>   + version=2.6.32-21-generic
>>>   + exec perf_2.6.32-21-generic
>>>   /usr/bin/perf: line 4: exec: perf_2.6.32-21-generic: not found
>>>
>>> - the PAE flavour has a version string ending in -generic-pae, but the
>>> version cleaning in the perf script doesn't handle the multiple flavour
>>> strings correctly. The perf tool is named perf_2.6.32-21, not
>>> perf_2.6.32-21-generic.
>>>
>>> This change fixes the perf wrapper script to throw away version data
>>> after a 'dash, non-digit' sequence instead of just the last dash. This
>>> fixes the problem on the PAE kernel. We need to do a special pass for
>>> the -386 flavour, as it's virtually indisinguishable from a normal
>>> version number. Testing this parsing against the possible flavours
>>> gives:
>>>
>>>          2.6.32-21-generic ->   2.6.32-21
>>>           2.6.32-21-server ->   2.6.32-21
>>>          2.6.32-21-preempt ->   2.6.32-21
>>>        2.6.32-21-versatile ->   2.6.32-21
>>>          2.6.32-21-generic ->   2.6.32-21
>>>      2.6.32-21-generic-pae ->   2.6.32-21
>>>              2.6.32-21-386 ->   2.6.32-21
>>>             2.6.32-21-ia64 ->   2.6.32-21
>>>             2.6.32-21-lpia ->   2.6.32-21
>>>          2.6.32-21-powerpc ->   2.6.32-21
>>>      2.6.32-21-powerpc-smp ->   2.6.32-21
>>>    2.6.32-21-powerpc64-smp ->   2.6.32-21
>>>          2.6.32-21-sparc64 ->   2.6.32-21
>>>      2.6.32-21-sparc64-smp ->   2.6.32-21
>>>
>>> Signed-off-by: Jeremy Kerr<jeremy.kerr at canonical.com>
>>>
>>> ---
>>>   debian/tools/perf |    3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/debian/tools/perf b/debian/tools/perf
>>> index 1a9915f..33df59d 100644
>>> --- a/debian/tools/perf
>>> +++ b/debian/tools/perf
>>> @@ -1,4 +1,5 @@
>>>   #!/bin/bash
>>>   version=`uname -r`
>>> -version=${version%-*}
>>> +version=${version/-[^0-9]*}
>>> +version=${version%-386}
>>>   exec "perf_$version" "$@"
>>>
>>
>> Why not just drop everything after the second '-' inclusive ?
>>
>> rtg
>> --
>> Tim Gardner tim.gardner at canonical.com
>
>>  From f935a6337ea4a1b8d7061fc249cbbfa13c38f631 Mon Sep 17 00:00:00 2001
>> From: Tim Gardner<tim.gardner at canonical.com>
>> Date: Wed, 21 Apr 2010 07:24:13 -0600
>> Subject: [PATCH] UBUNTU: Do a better job of stripping version information from the perf binary name
>>
>> Signed-off-by: Tim Gardner<tim.gardner at canonical.com>
>> ---
>>   debian/tools/perf |    3 +--
>>   1 files changed, 1 insertions(+), 2 deletions(-)
>>
>> diff --git a/debian/tools/perf b/debian/tools/perf
>> index 1a9915f..7a3c10b 100644
>> --- a/debian/tools/perf
>> +++ b/debian/tools/perf
>> @@ -1,4 +1,3 @@
>>   #!/bin/bash
>> -version=`uname -r`
>> -version=${version%-*}
>> +version=`uname -r|sed 's/\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)-\([0-9]*\)-.*$/\1\.\2\.\3-\4/'`
>>   exec "perf_$version" "$@"
>
> Yes we should use the known bits here.  I would prefer to avoid the
> additional fork here if possible.  I think we can do that, see my other
> reply for an alternative patch.
>
> -apw

meh. I have no strong opinion.

-- 
Tim Gardner tim.gardner at canonical.com