[PATCH] lockdep: i386 remove multi entry backtraces
Remove CONFIG_STACK_BACKTRACE_COLS.
This feature didnt work out: instead of making kernel debugging more
efficient, it produces much harder to read stacktraces! Check out this trace
for example:
http://static.flickr.com/47/158326090_35d0129147_b_d.jpg
That backtrace could have been printed much nicer as a one-entry-per-line
thing, taking the same amount of screen real-estate.
Plus we remove 30 lines of kernel code as well.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/Kconfig.debug b/arch/i386/Kconfig.debug
index c92191b..b20ddd0 100644
--- a/arch/i386/Kconfig.debug
+++ b/arch/i386/Kconfig.debug
@@ -31,15 +31,6 @@
This option will slow down process creation somewhat.
-config STACK_BACKTRACE_COLS
- int "Stack backtraces per line" if DEBUG_KERNEL
- range 1 3
- default 2
- help
- Selects how many stack backtrace entries per line to display.
-
- This can save screen space when displaying traces.
-
comment "Page alloc debug is incompatible with Software Suspend on i386"
depends on DEBUG_KERNEL && SOFTWARE_SUSPEND
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index e8c6086..2bf8b55 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -115,28 +115,13 @@
}
/*
- * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
+ * Print one address/symbol entries per line.
*/
-static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
- int printed)
+static inline void print_addr_and_symbol(unsigned long addr, char *log_lvl)
{
- if (!printed)
- printk(log_lvl);
-
-#if CONFIG_STACK_BACKTRACE_COLS == 1
printk(" [<%08lx>] ", addr);
-#else
- printk(" <%08lx> ", addr);
-#endif
- print_symbol("%s", addr);
- printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
- if (printed)
- printk(" ");
- else
- printk("\n");
-
- return printed;
+ print_symbol("%s\n", addr);
}
static inline unsigned long print_context_stack(struct thread_info *tinfo,
@@ -144,12 +129,11 @@
char *log_lvl)
{
unsigned long addr;
- int printed = 0; /* nr of entries already printed on current line */
#ifdef CONFIG_FRAME_POINTER
while (valid_stack_ptr(tinfo, (void *)ebp)) {
addr = *(unsigned long *)(ebp + 4);
- printed = print_addr_and_symbol(addr, log_lvl, printed);
+ print_addr_and_symbol(addr, log_lvl);
/*
* break out of recursive entries (such as
* end_of_stack_stop_unwind_function):
@@ -162,28 +146,23 @@
while (valid_stack_ptr(tinfo, stack)) {
addr = *stack++;
if (__kernel_text_address(addr))
- printed = print_addr_and_symbol(addr, log_lvl, printed);
+ print_addr_and_symbol(addr, log_lvl);
}
#endif
- if (printed)
- printk("\n");
-
return ebp;
}
-static asmlinkage int show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
+static asmlinkage int
+show_trace_unwind(struct unwind_frame_info *info, void *log_lvl)
{
int n = 0;
- int printed = 0; /* nr of entries already printed on current line */
while (unwind(info) == 0 && UNW_PC(info)) {
- ++n;
- printed = print_addr_and_symbol(UNW_PC(info), log_lvl, printed);
+ n++;
+ print_addr_and_symbol(UNW_PC(info), log_lvl);
if (arch_unw_user_mode(info))
break;
}
- if (printed)
- printk("\n");
return n;
}
