Commit:     79b4cc5ee7a8086ac2c9c0afa52e6d687ce1ffef
Parent:     3a6a62f96f168d192fb0cc9c0b5ee2584740b32d
Author:     Arjan van de Ven <[EMAIL PROTECTED]>
AuthorDate: Wed Jan 30 13:32:50 2008 +0100
Committer:  Ingo Molnar <[EMAIL PROTECTED]>
CommitDate: Wed Jan 30 13:32:50 2008 +0100

    debug: move WARN_ON() out of line
    A quick grep shows that there are currently 1145 instances of WARN_ON
    in the kernel. Currently, WARN_ON is pretty much entirely inlined,
    which makes it hard to enhance it without growing the size of the kernel
    (and getting Andrew unhappy).
    This patch build on top of Olof's patch that introduces __WARN,
    and places the slowpath out of line. It also uses Ingo's suggestion
    to not use __FUNCTION__ but to use kallsyms to do the lookup;
    this saves a ton of extra space since gcc doesn't need to store the function
    string twice now:
    3936367  833603  624736 5394706  525112 vmlinux.before
    3917508  833603  624736 5375847  520767 vmlinux-slowpath
    15Kb savings...
    Signed-off-by: Arjan van de Ven <[EMAIL PROTECTED]>
    CC: Andrew Morton <[EMAIL PROTECTED]>
    CC: Olof Johansson <[EMAIL PROTECTED]>
    Acked-by: Matt Meckall <[EMAIL PROTECTED]>
    Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
    Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
 include/asm-generic/bug.h |   10 +++++-----
 kernel/panic.c            |   15 +++++++++++++++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index 1a0e1a7..2632328 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -32,11 +32,11 @@ struct bug_entry {
 #ifndef __WARN
-#define __WARN() do {                                                  \
-       printk("WARNING: at %s:%d %s()\n", __FILE__,                    \
-               __LINE__, __FUNCTION__);                                \
-       dump_stack();                                                   \
-} while (0)
+#ifndef __ASSEMBLY__
+extern void warn_on_slowpath(const char *file, const int line);
+#define __WARN() warn_on_slowpath(__FILE__, __LINE__)
 #ifndef WARN_ON
diff --git a/kernel/panic.c b/kernel/panic.c
index da4d6ba..0ebea43 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -20,6 +20,7 @@
 #include <linux/kexec.h>
 #include <linux/debug_locks.h>
 #include <linux/random.h>
+#include <linux/kallsyms.h>
 int panic_on_oops;
 int tainted;
@@ -292,6 +293,20 @@ void oops_exit(void)
                (unsigned long long)oops_id);
+void warn_on_slowpath(const char *file, int line)
+       char function[KSYM_SYMBOL_LEN];
+       unsigned long caller = (unsigned long) __builtin_return_address(0);
+       sprint_symbol(function, caller);
+       printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
+               line, function);
+       dump_stack();
  * Called when gcc's -fstack-protector feature is used, and
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