lkml.org 
[lkml]   [2019]   [Sep]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH 1/2] Fix: sched/membarrier: p->mm->membarrier_state racy load
with or without these changes...

Why do membarrier_register_*_expedited() check get_nr_threads() == 1?
This makes no sense to me, atomic_read(mm_users) == 1 should be enough.


And I am not sure I understand membarrier_mm_sync_core_before_usermode().
OK, membarrier_private_expedited() can race with user -> kernel -> user
transition, but we do not care unless both user's above have the same mm?
Shouldn't membarrier_mm_sync_core_before_usermode() do

if (current->mm != mm)
return;

at the start to make it more clear and avoid sync_core_before_usermode()
if possible?

Oleg.

\
 
 \ /
  Last update: 2019-09-04 13:12    [W:0.067 / U:0.588 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site