lkml.org 
[lkml]   [2018]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: objtool warnings for kernel/trace/trace_selftest_dynamic.o
On Mon, Dec 17, 2018 at 12:55:35PM -0800, Andi Kleen wrote:
> On Mon, Dec 17, 2018 at 08:29:38PM +0100, Peter Zijlstra wrote:
> > When/if we get the LTO trainwreck sorted -- which very much includes
> > getting that memory-order-consume fixed -- we can revisit all that.
>
> What do you mean? I'm not aware of any LTO problems with memory-order-consume?

The compiler is basically allowed to break RCU (and anything else that
depends on read-read dependencies). LTO makes it _far_ more likely this
happens.

We need guarantees (and possible switches) from the compiler folks that
this will not happen before I'll retract my NAK from any LTO enabling.

\
 
 \ /
  Last update: 2018-12-17 23:35    [W:0.109 / U:0.360 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site