From: Peter Zijlstra <peterz@infradead.org>
To: Nathan Chancellor <nathan@kernel.org>
Cc: kernel test robot <lkp@intel.com>,
Yafang Shao <laoar.shao@gmail.com>,
llvm@lists.linux.dev, kbuild-all@lists.01.org,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [tip:sched/core 14/47] kernel/sched/fair.c:893:22: error: variable 'p' set but not used
Date: Thu, 14 Oct 2021 17:08:59 +0200 [thread overview]
Message-ID: <YWhIC30vBoOgXxie@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <YWew3ItdPC5QrL/w@archlinux-ax161>
On Wed, Oct 13, 2021 at 09:23:56PM -0700, Nathan Chancellor wrote:
> On Tue, Oct 12, 2021 at 03:35:42PM +0200, Peter Zijlstra wrote:
> > On Tue, Oct 12, 2021 at 01:26:54PM +0200, Peter Zijlstra wrote:
> >
> > > Again, I have absolutely no intention of fixing this. IMO this is the
> > > compiler being a total pain in the arse.
> > >
> > > Please stop reporting this.
> >
> > How's this then?
> >
> > diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
> > index 978fcfca5871..b0d9121c5dce 100644
> > --- a/kernel/sched/Makefile
> > +++ b/kernel/sched/Makefile
> > @@ -3,6 +3,10 @@ ifdef CONFIG_FUNCTION_TRACER
> > CFLAGS_REMOVE_clock.o = $(CC_FLAGS_FTRACE)
> > endif
> >
> > +# The compilers are complaining about unused variables inside an if(0) scope
> > +# block. This is daft, shut them up.
> > +ccflags-y += -Wno-unused-but-set-variable
>
> Please consider making this
>
> ccflags-y += $(call cc-disable-warning, unused-but-set-variable)
Ooh, shiny, will do.
> because -Wunused-but-set-variable was only added to clang in the 13
> release but we support back to 10, meaning this will cause errors for
> those older compilers.
>
> With that:
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
>
> Additionally, perhaps this could be restricted to just fair.c?
It triggers in a bunch of files, given the right config (defconfig -SCHEDSTATS +SCHED_DEBUG)
(and I have a pile of patches for most of the other warnings somewhere...)
---
# make O=defconfig-build/ kernel/sched/ -j8 -s W=1
../kernel/sched/deadline.c: In function ‘update_stats_wait_start_dl’:
../kernel/sched/deadline.c:1486:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
1486 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/deadline.c: In function ‘update_stats_wait_end_dl’:
../kernel/sched/deadline.c:1498:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
1498 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/deadline.c: In function ‘update_stats_enqueue_sleeper_dl’:
../kernel/sched/deadline.c:1510:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
1510 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c: In function ‘update_curr’:
../kernel/sched/fair.c:860:28: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
860 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c: In function ‘update_stats_wait_start_fair’:
../kernel/sched/fair.c:893:22: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
893 | struct task_struct *p = NULL;
| ^
../kernel/sched/fair.c:892:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
892 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c: In function ‘update_stats_wait_end_fair’:
../kernel/sched/fair.c:910:22: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
910 | struct task_struct *p = NULL;
| ^
../kernel/sched/fair.c:909:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
909 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c: In function ‘update_stats_enqueue_sleeper_fair’:
../kernel/sched/fair.c:936:22: warning: variable ‘tsk’ set but not used [-Wunused-but-set-variable]
936 | struct task_struct *tsk = NULL;
| ^~~
../kernel/sched/fair.c:935:27: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
935 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c: In function ‘set_next_entity’:
../kernel/sched/fair.c:4450:28: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
4450 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/rt.c:669:6: warning: no previous prototype for ‘sched_rt_bandwidth_account’ [-Wmissing-prototypes]
669 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
../kernel/sched/rt.c: In function ‘update_stats_wait_start_rt’:
../kernel/sched/rt.c:1292:22: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
1292 | struct task_struct *p = NULL;
| ^
../kernel/sched/rt.c: In function ‘update_stats_enqueue_sleeper_rt’:
../kernel/sched/rt.c:1311:22: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
1311 | struct task_struct *p = NULL;
| ^
../kernel/sched/rt.c: In function ‘update_stats_wait_end_rt’:
../kernel/sched/rt.c:1341:22: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
1341 | struct task_struct *p = NULL;
| ^
../kernel/sched/core.c:3420:6: warning: no previous prototype for ‘sched_set_stop_task’ [-Wmissing-prototypes]
3420 | void sched_set_stop_task(int cpu, struct task_struct *stop)
| ^~~~~~~~~~~~~~~~~~~
../kernel/sched/debug.c: In function ‘print_cfs_group_stats’:
../kernel/sched/debug.c:466:28: warning: variable ‘stats’ set but not used [-Wunused-but-set-variable]
466 | struct sched_statistics *stats;
| ^~~~~
../kernel/sched/fair.c:8673: warning: Function parameter or member 'sds' not described in 'update_sg_lb_stats'
next prev parent reply other threads:[~2021-10-14 15:09 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-12 3:57 [tip:sched/core 14/47] kernel/sched/fair.c:893:22: error: variable 'p' set but not used kernel test robot
2021-10-12 11:26 ` Peter Zijlstra
2021-10-12 13:35 ` Peter Zijlstra
2021-10-13 6:18 ` Yafang Shao
2021-10-14 4:23 ` Nathan Chancellor
2021-10-14 15:08 ` Peter Zijlstra [this message]
2021-10-12 14:31 ` [kbuild-all] " Chen, Rong A
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