lkml.org 
[lkml]   [2019]   [Jan]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 0/6] Static calls
On Fri, 11 Jan 2019, hpa@zytor.com wrote:

> I still don't see why can't simply spin in the #BP handler until the
> patch is complete.

I think this brings us to the already discussed possible deadlock, when
one CPU#0 is in the middle of text_poke_bp(), CPU#1 is spinning inside
spin_lock_irq*(&lock) and CPU#2 hits the breakpont while holding that very
'lock'.

Then we're stuck forever, because CPU#1 will never handle the pending
sync_core() IPI (it's not NMI).

Or have I misunderstood what you meant?

--
Jiri Kosina
SUSE Labs

\
 
 \ /
  Last update: 2019-01-11 20:39    [W:0.094 / U:2.020 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site