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

[Andy Whitcroft]

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