lkml.org 
[lkml]   [2022]   [Aug]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC] ftrace: Add support to keep some functions out of ftrace
On Mon, Aug 15, 2022 at 05:48:44PM +0200, Peter Zijlstra wrote:
> On Mon, Aug 15, 2022 at 08:35:53AM -0700, Alexei Starovoitov wrote:
> > On Mon, Aug 15, 2022 at 8:28 AM Peter Zijlstra <peterz@infradead.org> wrote:
> > >
> > > On Mon, Aug 15, 2022 at 08:17:42AM -0700, Alexei Starovoitov wrote:
> > > > It's hiding a fake function from ftrace, since it's not a function
> > > > and ftrace infra shouldn't show it tracing logs.
> > > > In other words it's a _notrace_ function with nop5.
> > >
> > > Then make it a notrace function with a nop5 in it. That isn't hard.
> >
> > That's exactly what we're trying to do.
>
> All the while claiming ftrace is broken while it is not.
>
> > Jiri's patch is one way to achieve that.
>
> Fairly horrible way.
>
> > What is your suggestion?
>
> Mailed it already.
>
> > Move it from C to asm ?
>
> Would be much better than proposed IMO.

nice, that would be independent of the compiler atributes
and config checking.. will check on this one ;-)

thanks,
jirka

>
> > Make it naked function with explicit inline asm?
>
> Can be made to work but is iffy because the compiler can do horrible
> things with placing the asm().

\
 
 \ /
  Last update: 2022-08-16 10:53    [W:0.022 / U:0.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site