From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 37C382C85 for ; Thu, 14 Oct 2021 15:09:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=W5pw2CE/uzyiW+aTpQ3ZuIwrhdvcki06u9/0gkIPEBc=; b=euISmwXBiaLKhCbaEMBPqxPsdq daMFJJNgNxPMA2U/OltF7Z7QpwfpX/6jKE/UFAnCglhWVvLz/v+hPrrrp/xHXLhoubB++R1vqnJDs 42Epm8kGWy3IhFfZDF5nvMyr+aR1Vq7Fx/8vTRbPh5gPh42KWhuyzPeor/0eWUzbtkYFvGvOsg5w9 RId0pNOPM2bOMSuZTls9taTomwj0w44piVkXROyETnV5yrALMq6y0i35+yRtGoiUGgYmYGYifTdd6 TaJ6AA2A4x3Wp+bpbl7++RNu/VcGXLiXxn+14v6VoGNLynnC68DA0SSxjkawPFQOoLTDBkgdhk4+6 bzAaazgg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mb2Ls-009qwq-Ls; Thu, 14 Oct 2021 15:09:00 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 7602F30030B; Thu, 14 Oct 2021 17:08:59 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6258C20A958AF; Thu, 14 Oct 2021 17:08:59 +0200 (CEST) Date: Thu, 14 Oct 2021 17:08:59 +0200 From: Peter Zijlstra To: Nathan Chancellor Cc: kernel test robot , Yafang Shao , 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 Message-ID: References: <202110121132.N2z9JrD0-lkp@intel.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: 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 > > 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'