]> git.karo-electronics.de Git - karo-tx-linux.git/commit
Fix for enabling branch profiling makes sparse unusable
authorBart Van Assche <bart.vanassche@gmail.com>
Sat, 9 May 2009 09:43:44 +0000 (11:43 +0200)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 18 May 2009 23:34:41 +0000 (16:34 -0700)
commita23e0b520920e6de02ceeb0f4e67a0463194f77a
treea5e93d9e199b6d96ef0849f758f430410e5c8b6a
parent5ece6d71d896061e517f517ad20d0d865b923622
Fix for enabling branch profiling makes sparse unusable

commit d9ad8bc0ca823705413f75b50c442a88cc518b35 upstream.

One of the changes between kernels 2.6.28 and 2.6.29 is that a branch profiler
has been added for if() statements. Unfortunately this patch makes the sparse
output unusable with CONFIG_TRACE_BRANCH_PROFILING=y: when branch profiling is
enabled, sparse prints so much false positives that the real issues are no
longer visible. This behavior can be reproduced as follows:
* enable CONFIG_TRACE_BRANCH_PROFILING, e.g. by running make allyesconfig or
  make allmodconfig.
* run make C=2

Result: a huge number of the following sparse warnings.
...
include/linux/cpumask.h:547:2: warning: symbol '______r' shadows an earlier one
include/linux/cpumask.h:547:2: originally declared here
...

The patch below fixes this by disabling branch profiling while analyzing the
kernel code with sparse.

This patch is already included in 2.6.30-rc1 -- see also
http://lkml.org/lkml/2009/4/5/120.

Signed-off-by: Bart Van Assche <bart.vanassche@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <srostedt@redhat.com>
LKML-Reference: <200904051620.02311.bart.vanassche@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
include/linux/compiler.h