On Fri, 22 Feb 2008 19:44:05 +0100
Vegard Nossum <[EMAIL PROTECTED]> wrote:
> I find the following patch to make saved stack traces so much easier
> to decipher. There might be other uses of save_stack_trace() that I
> am not aware of, though. Also, I suggest changing the underlying
> struct stack_trace to include the reliable/unreliable information.
> This, however, requires all users of save_stack_trace() and all
> arches saving this information to change.
>
> Kind regards,
> Vegard Nossum
>
>
> From 5edfd896c5f0d728111df3d8cae729a375f29d3c Mon Sep 17 00:00:00
> 2001 From: Vegard Nossum <[EMAIL PROTECTED]>
> Date: Fri, 22 Feb 2008 19:23:58 +0100
> Subject: [PATCH] x86: don't save unreliable stack trace entries
>
> Currently, there is no way for print_stack_trace() to determine
> whether a given stack trace entry was deemed reliable or not, simply
> because save_stack_trace() does not record this information. (Perhaps
> needless to say, this makes the saved stack traces A LOT harder to
> read, and probably with no other benefits, since debugging features
> that use save_stack_trace() most likely also require frame pointers,
> etc.)
>
> This patch reverts to the old behaviour of only recording the
> reliable trace entries for saved stack traces.
>
> Signed-off-by: Vegard Nossum <[EMAIL PROTECTED]>
> ---
> arch/x86/kernel/stacktrace.c | 4 ++++
> 1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/stacktrace.c
> b/arch/x86/kernel/stacktrace.c index 02f0f61..c28c342 100644
> --- a/arch/x86/kernel/stacktrace.c
> +++ b/arch/x86/kernel/stacktrace.c
> @@ -25,6 +25,8 @@ static int save_stack_stack(void *data, char *name)
> static void save_stack_address(void *data, unsigned long addr, int
> reliable) {
> struct stack_trace *trace = data;
> + if (!reliable)
> + return;
> if (trace->skip > 0) {
> trace->skip--;
> return;
> @@ -37,6 +39,8 @@ static void
> save_stack_address_nosched(void *data, unsigned long addr, int
> reliable) {
> struct stack_trace *trace = (struct stack_trace *)data;
> + if (!reliable)
> + return;
> if (in_sched_functions(addr))
> return;
> if (trace->skip > 0) {
I was about to make a patch for this second chunk myself and submit it, so
for the second chunk a strong:
Acked-by: Arjan van de Ven <[EMAIL PROTECTED]>
Thanks for beating me to it ;-)
--
If you want to reach me at my work email, use [EMAIL PROTECTED]
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
