Re: [PATCH v3 1/4] printk/nmi: Generic solution for safe printk in NMI

2015-12-10 Thread Petr Mladek
On Wed 2015-12-09 15:50:07, Andrew Morton wrote: > On Wed, 9 Dec 2015 14:21:02 +0100 Petr Mladek wrote: > > > printk() takes some locks and could not be used a safe way in NMI > > context. > > > > The chance of a deadlock is real especially when printing > > stacks from all CPUs. This particula

Re: [PATCH v3 1/4] printk/nmi: Generic solution for safe printk in NMI

2015-12-09 Thread Andrew Morton
On Wed, 9 Dec 2015 14:21:02 +0100 Petr Mladek wrote: > printk() takes some locks and could not be used a safe way in NMI > context. > > The chance of a deadlock is real especially when printing > stacks from all CPUs. This particular problem has been addressed > on x86 by the commit a9edc880932

[PATCH v3 1/4] printk/nmi: Generic solution for safe printk in NMI

2015-12-09 Thread Petr Mladek
printk() takes some locks and could not be used a safe way in NMI context. The chance of a deadlock is real especially when printing stacks from all CPUs. This particular problem has been addressed on x86 by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). This pat