lkml.org 
[lkml]   [2017]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] sched/deadline: Use bools for the state flags
On Tue, 21 Nov 2017, Jiri Kosina wrote:

> From: Jiri Kosina <jkosina@suse.cz>
>
> Commit
>
> 799ba82de01e ("sched/deadline: Use C bitfields for the state flags")
>
> converted state flags into one-bit signed int. Signed one-bit type can be
> either 0 or -1, which is going to cause a problem once 1 is assigned to it
> and then the value later tested against 1.
>
> The current code is okay, as all the checks are (non-)zero check, but I
> believe that we'd rather be safe than sorry here; remove the fragility by
> converting the state flags to bool.
>
> This also silences annoying sparse complaints about this very issue when
> compiling any code that includes sched.h.

What's wrong with making these bitfields 'unsigned int' ?

> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index a5dc7c98b0a2..b19fa1b96726 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -473,10 +473,10 @@ struct sched_dl_entity {
> * conditions between the inactive timer handler and the wakeup
> * code.
> */
> - int dl_throttled : 1;
> - int dl_boosted : 1;
> - int dl_yielded : 1;
> - int dl_non_contending : 1;
> + bool dl_throttled;
> + bool dl_boosted;
> + bool dl_yielded;
> + bool dl_non_contending;

Thanks,

tglx

\
 
 \ /
  Last update: 2017-11-21 11:54    [W:0.078 / U:10.628 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site