lkml.org 
[lkml]   [2017]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3] KVM: async_pf: rcu irq exit if not triggered from idle task
From
Date
On 27/07/2017 11:05, Wanpeng Li wrote:
> Commit 9b132fbe5419 (Add rcu user eqs exception hooks for async page fault)
> adds rcu_irq_enter/exit() to kvm_async_pf_task_wait() to exit cpu idle eqs
> when needed, to protect the code that needs use rcu. There is no need to call
> this pairs if async page fault is not triggered from idle task.

This is true, but I think the patch is making things more complex where
it could be simplifying them. Right now, the "native_safe_halt" branch
is calling rcu_irq_exit/enter but the "schedule" branch is not. Could
you just pull rcu_irq_exit/enter outside the "if", so that you inform
the RCU subsystem even in the !n.halted case?

Paolo

\
 
 \ /
  Last update: 2017-08-01 12:38    [W:0.046 / U:10.580 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site