Re: Next round: revised futex(2) man page for review

["Michael Kerrisk (man-pages)" <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 07/28/2015 11:03 PM, Thomas Gleixner wrote:
> On Tue, 28 Jul 2015, Peter Zijlstra wrote:
> 
>> 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'.
> 
> Indeed.
>  
>> 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?
> 
> I think so.

So, no change to this piece of text then?

Cheers,

Michael


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/