[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20150728204508.GG19282@twins.programming.kicks-ass.net>
Date: Tue, 28 Jul 2015 22:45:08 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: Thomas Gleixner <tglx@...utronix.de>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>,
Darren Hart <dvhart@...radead.org>,
Torvald Riegel <triegel@...hat.com>,
Carlos O'Donell <carlos@...hat.com>,
Ingo Molnar <mingo@...e.hu>, Jakub Jelinek <jakub@...hat.com>,
linux-man <linux-man@...r.kernel.org>,
lkml <linux-kernel@...r.kernel.org>,
Davidlohr Bueso <dave@...olabs.net>,
Arnd Bergmann <arnd@...db.de>,
Steven Rostedt <rostedt@...dmis.org>,
Linux API <linux-api@...r.kernel.org>,
Roland McGrath <roland@...k.frob.com>,
Anton Blanchard <anton@...ba.org>,
Eric Dumazet <edumazet@...gle.com>,
bill o gallmeister <bgallmeister@...il.com>,
Jan Kiszka <jan.kiszka@...mens.com>,
Daniel Wagner <wagi@...om.org>, Rich Felker <dalias@...c.org>,
Andy Lutomirski <luto@...capital.net>,
bert hubert <bert.hubert@...herlabs.nl>,
Rusty Russell <rusty@...tcorp.com.au>,
Heinrich Schuchardt <xypron.glpk@....de>
Subject: Re: Next round: revised futex(2) man page for review
On Tue, Jul 28, 2015 at 10:23:51PM +0200, Thomas Gleixner wrote:
> > FUTEX_WAKE (since Linux 2.6.0)
> > This operation wakes at most val of the waiters that are
> > waiting (e.g., inside FUTEX_WAIT) on the futex word at the
> > address uaddr. Most commonly, val is specified as either
> > 1 (wake up a single waiter) or INT_MAX (wake up all wait‐
> > ers). No guarantee is provided about which waiters are
> > awoken (e.g., a waiter with a higher scheduling priority
> > is not guaranteed to be awoken in preference to a waiter
> > with a lower priority).
>
> That's only correct up to Linux 2.6.21.
>
> Since 2.6.22 we have a priority ordered wakeup. For SCHED_OTHER
> threads this takes the nice level into account. Threads with the same
> priority are woken in FIFO order.
Maybe don't mention the effects of SCHED_OTHER, order by nice value is
'wrong'.
Also, this code seems to use plist, which means it won't do the right
thing for SCHED_DEADLINE either.
Do we want to go fix that?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists