path: root/lib
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authorAndi Kleen <andi@firstfloor.org>2010-07-14 15:43:52 +0200
committerMichal Marek <mmarek@suse.cz>2010-07-14 17:21:28 +0200
commitd6f4ceb796ebf1a8c8a9ad4a8ea0d181aaec7de6 (patch)
tree8fa46f7bab29be7ffd7108de3a2c0e5d0616ff07 /lib
parent01ab17887f4cdcb8bb5a5d1bc3b160d186e6e99b (diff)
Kbuild: Add option to set -femit-struct-debug-baseonly
Newer gcc has a -femit-struct-debug-baseonly option that dramatically reduces the size of object files with debug info. What it does is to only emit type information for structures when the structures are defined in the same file or in a header file. This means the type information for most headers are not included. This is not good when the type information is actually needed (e.g. with kgdb or systemtap) But often kernel hackers only care about line numbers and don't need all the type information anyways. In this case setting the option can be a big win: A build dir for a specific x86-64 configuration with gcc 4.5 shrunk from 2.3G to 1.2G. The compilation was also nearly a minute faster. Signed-off-by: Andi Kleen <ak@linux.intel.com> [mmarek: reformatted help text] Signed-off-by: Michal Marek <mmarek@suse.cz>
Diffstat (limited to 'lib')
1 files changed, 13 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 25c3ed594c5..2af5d84ec82 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -595,6 +595,19 @@ config DEBUG_INFO
If unsure, say N.
+ bool "Reduce debugging information"
+ depends on DEBUG_INFO
+ help
+ If you say Y here gcc is instructed to generate less debugging
+ information for structure types. This means that tools that
+ need full debugging information (like kgdb or systemtap) won't
+ be happy. But if you merely need debugging information to
+ resolve line numbers there is no loss. Advantage is that
+ build directory object sizes shrink dramatically over a full
+ DEBUG_INFO build and compile times are reduced too.
+ Only works with newer gcc versions.
config DEBUG_VM
bool "Debug VM"
depends on DEBUG_KERNEL