lkml.org 
[lkml]   [2018]   [Sep]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] printk/tracing: Do not trace printk_nmi_enter()
On (09/07/18 16:03), Peter Zijlstra wrote:
> >
> > I would even argue that placing printk_nmi_enter() between
> > lockdep_off() and ftrace_nmi_enter() is wrong because if in the future
> > printk_nmi_enter() were to do any ftrace tracing, it wont be caught, as
> > it was by having it before lockdep_off().
> >
> > printk_nmi_enter() should not muck with IRQ state, nor should it do any
> > ftrace tracing. Since ftrace mucks with IRQ state when it gets enabled
> > or disabled, it will screw up lockdep, and lockdep will complain. That
> > way we can use lockdep not being off to catch this bug.
>
> The very bestest solution is to rm -rf printk ;-)

Talented, capable and tremendously clever people had spent decades on
making printk what it is today. I feel responsible for respecting that
effort and, thus, my vote would be to keep printk around for a while.
... we also support !CONFIG_PRINTK builds ;)

-ss

\
 
 \ /
  Last update: 2018-09-07 16:53    [W:0.103 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site