[lkml]   [2017]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC] futex: hashbucket as list of futex instead of waiters
On Fri, Sep 29, 2017 at 12:39:32AM +0200, Gerd Gerats wrote:
> >
> > So I suppose the purpose of that plist in futex is to enable waking up
> > the highest prio waiter, but with the advent of SCHED_DEADLINE that no
> > longer works.
> I do not understand, plist is the original data structure. I assume, it works
> together with SCHED_DEADLINE.

plist does not work well with DEADLINE, all deadline tasks will get
lumped together at prio -1; prio as a single integer doesn't really work

We've converted the RT-mutes over to RB-trees a fair while ago; see

fb00aca47440 ("rtmutex: Turn the plist into an rb-tree")

> Or is there something on the way not pressent in 4.13.

Thomas held off on converting futex to rb-trees because, as he said
elsewhere in this thread, he's worried about the performance impact on

 \ /
  Last update: 2017-09-29 10:37    [W:0.051 / U:0.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site