lkml.org 
[lkml]   [2018]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Question about ->head field of rcu_segcblist
On Sun, Sep 23, 2018 at 07:31:37PM -0400, Joel Fernandes wrote:
> On Sun, Sep 23, 2018 at 7:30 PM Joel Fernandes <joel@joelfernandes.org> wrote:
> >
> > Hi Paul,
> >
> > I was parsing the Data-Structures document and had a question about
> > the following "Important note" text.
> >
> > Could it be clarified in the below text better why "remaining
> > callbacks are placed back on the RCU_DONE_TAIL segment", is a reason
> > for not depending on ->head for determining if no callbacks are
> > associated with the rcu_segcblist? If callbacks are added back to the
> > DONE_TAIL segment, then I would think rcu_head should be != NULL.
> > Infact the "rsclp->head = *rsclp->tails[RCU_DONE_TAIL];" in
> > rcu_segcblist_extract_done_cbs should set the ->head to NULL if I
> > understand correctly.
>
> Just to clarify, I meant set to NULL assuming all cbs were done
> waiting and ready to be invoked.

Ah, good, then that is correct. But even then, being NULL doesn't mean
no callbacks because they might be temporarily held by rcu_do_batch().

Thanx, Paul

\
 
 \ /
  Last update: 2018-09-24 01:55    [W:0.056 / U:0.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site