Re: [RFC PATCH 16/17] x86/nmi: Perform a safe NMI stack trace on all CPUs

2015-05-19 Thread long.wanglong
On 2015/5/18 22:17, Petr Mladek wrote: > On Thu 2015-05-14 11:35:03, Wang Long wrote: >> From: "Steven Rostedt (Red Hat)" >> >> commit a9edc88093287183ac934be44f295f183b2c62dd upstream. >> >> When trigger_all_cpu_backtrace() is called on x86, it will trigger an >> NMI on each CPU and call show_reg

Re: [RFC PATCH 16/17] x86/nmi: Perform a safe NMI stack trace on all CPUs

2015-05-18 Thread Petr Mladek
On Thu 2015-05-14 11:35:03, Wang Long wrote: > From: "Steven Rostedt (Red Hat)" > > commit a9edc88093287183ac934be44f295f183b2c62dd upstream. > > When trigger_all_cpu_backtrace() is called on x86, it will trigger an > NMI on each CPU and call show_regs(). But this can lead to a hard lock > up if

[RFC PATCH 16/17] x86/nmi: Perform a safe NMI stack trace on all CPUs

2015-05-14 Thread Wang Long
From: "Steven Rostedt (Red Hat)" commit a9edc88093287183ac934be44f295f183b2c62dd upstream. When trigger_all_cpu_backtrace() is called on x86, it will trigger an NMI on each CPU and call show_regs(). But this can lead to a hard lock up if the NMI comes in on another printk(). In order to avoid t