Messages in this thread | | | Date | Tue, 21 Jul 2015 11:34:12 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 0/3] Shared NMI backtracing support for ARM/x86 |
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On Wed, 15 Jul 2015, Russell King - ARM Linux wrote: > Back in September, I stumbled across a single CPU IRQs-off lockup of an > ARM SMP system, and decided to hack something together based on a much > older hacky implementation used with StrongARM CPUs from early 2000s. > > This resulted in a copy of the x86 NMI backtrace code into ARM as it was > back then, and feedback indicated that it wasn't a good time to push > such an effort forward, as printk() in NMI context is dodgy. > > Over time, the x86 code has had this problem addressed, and last week > I updated the patch which I've been carrying in my tree to move the > shared code out of arch/x86 into lib/ rather than duplicating it, and > switch the ARM implementation to use it. > > Discussing this with Thomas Gliexner, he agreed to give it a test over > last weekend, and he has reported to me this evening "no explosion so > far". Since then, I've made a change to add the NOKPROBE_SYMBOL() to > the generic handler as per the x86 original code. > > I'm aware that there are other competing implementations out there - > Daniel has one based on my patch from September time, but I don't think > that goes far enough with code sharing. I'm also partially aware of > an implementation from Petr too.
I think we should just move ahead and apply this lot. Any improvements can be done on top of this.
Russell, please take it through your tree.
Thanks,
tglx
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