Do you think we should add the same change to dumpstack_64.c too.
Looks like you addressed Alan's comments already (i.e. use of unlikely not
needed, us %p, and use pr_warn instead of printk)
--mark
> -----Original Message-----
> From: Liu, Chuansheng
> Sent: Sunday, August 26, 2012 6:56 PM
> To: 'linux-kernel@vger.kernel.org' (linux-kernel@vger.kernel.org)
> Cc: h...@linux.intel.com; Gross, Mark; a...@linux.intel.com
> Subject: [PATCH RESEND] x86_dump_trace: avoiding endless " <IRQ> " is
> printed
>
> From: liu chuansheng <chuansheng....@intel.com>
> Subject: [PATCH] x86_dump_trace: avoiding endless " <IRQ> " is printed
>
> Found the case that endless " <IRQ> " printing in dump_trace, and no real
> meaningful stack traces are output, so there should be one rare case that
> possibly context->previous_esp = context or other cases.
>
> The endless " <IRQ> " is as below:
> ...
> [ 82.215244,0] <IRQ>
> [ 82.215399,0] <IRQ>
> [ 82.215554,0] <IRQ>
> [ 82.215710,0] <IRQ>
> [ 82.215865,0] <IRQ>
> [ 82.216022,0] <IRQ>
> [ 82.216178,0] <IRQ>
> [ 82.216333,0] <IRQ>
> [ 82.216488,0] <IRQ>
> [ 82.216643,0] <IRQ>
> [ 82.216798,0] <IRQ>
> [ 82.216953,0] <IRQ>
> ...
>
> This patch aim is:
> 1/ Limiting the " <IRQ> " outputing, currently the max IRQ contexts is
> 2(softirq+harirq combination); 2/ When the max IRQ contexts 2 is reached,
> print the context content to confirm;
>
> Change-Id: I6d72aa71c4c5ff8f9e6ae133b3f6bfec8887750d
> Signed-off-by: liu chuansheng <chuansheng....@intel.com>
> ---
> arch/x86/kernel/dumpstack_32.c | 11 +++++++++++
> 1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/dumpstack_32.c
> b/arch/x86/kernel/dumpstack_32.c index 1038a41..410fa38 100644
> --- a/arch/x86/kernel/dumpstack_32.c
> +++ b/arch/x86/kernel/dumpstack_32.c
> @@ -22,6 +22,7 @@ void dump_trace(struct task_struct *task, struct pt_regs
> *regs,
> const struct stacktrace_ops *ops, void *data) {
> int graph = 0;
> + int dump_irq_count = 0;
>
> if (!task)
> task = current;
> @@ -47,8 +48,18 @@ void dump_trace(struct task_struct *task, struct
> pt_regs *regs,
> stack = (unsigned long *)context->previous_esp;
> if (!stack)
> break;
> +
> + if (dump_irq_count > 2) {
> + pr_warn("break multi-IRQ print,"
> + "context=%p, stack=%p\n",
> + context,
> + stack);
> + break;
> + }
> +
> if (ops->stack(data, "IRQ") < 0)
> break;
> + dump_irq_count++;
> touch_nmi_watchdog();
> }
> }
> --
> 1.7.0.4
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