lkml.org 
[lkml]   [2015]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Documentation: Remove misleading examples of the barriers in wake_*()
On Thu, Sep 24, 2015 at 09:21:22PM +0800, Boqun Feng wrote:
> > Included in it are some of the details on this subject, because a wakeup
> > has two prior states that are of importance, the tasks own prior state
> > and the wakeup state, both should be considered in the 'program order'
> > flow.
> >
>
> Great and very helpful ;-)
>
> > So maybe we can reduce the description in memory-barriers to this
> > 'split' program order guarantee, where a woken task must observe both
> > its own prior state and its wakee state.
> ^^^^^
> I think you mean "waker" here, right?

Yes.

> And the waker is not necessarily the same task who set the @cond to
> true, right?

It should be.

> If so, I feel like it's really hard to *use* this 'split'
> program order guarantee in other places than sleep/wakeup itself. Could
> you give an example? Thank you.

It was not meant to be used in any other scenario; the 'split' PO really
is part of the whole sleep/wakeup. It does not apply to anything else.


\
 
 \ /
  Last update: 2015-10-06 18:21    [W:0.841 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site