From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5E4F7C11F64 for ; Thu, 1 Jul 2021 13:20:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3748661416 for ; Thu, 1 Jul 2021 13:20:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236640AbhGANW6 (ORCPT ); Thu, 1 Jul 2021 09:22:58 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:64656 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236587AbhGANWu (ORCPT ); Thu, 1 Jul 2021 09:22:50 -0400 Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4GFytj08T5zB9np; Thu, 1 Jul 2021 14:58:05 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id F3Q4u9vNdjG6; Thu, 1 Jul 2021 14:58:04 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4GFytg6LvnzB9pC; Thu, 1 Jul 2021 14:58:03 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C88098B903; Thu, 1 Jul 2021 14:58:03 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id uOkqtDmpu2rb; Thu, 1 Jul 2021 14:58:03 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 62FDB8B961; Thu, 1 Jul 2021 14:58:03 +0200 (CEST) Subject: Re: [PATCH] sched: Use WARN_ON To: Jason Wang , jk@ozlabs.org Cc: arnd@arndb.de, linux-kernel@vger.kernel.org, paulus@samba.org, linuxppc-dev@lists.ozlabs.org References: <20210701125046.43018-1-wangborong@cdjrlc.com> From: Christophe Leroy Message-ID: Date: Thu, 1 Jul 2021 14:57:59 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210701125046.43018-1-wangborong@cdjrlc.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 01/07/2021 à 14:50, Jason Wang a écrit : > The BUG_ON macro simplifies the if condition followed by BUG, but it > will lead to the kernel crashing. Therefore, we can try using WARN_ON > instead of if condition followed by BUG. But are you sure it is ok to continue if spu_acquire(ctx) returned false ? Shouldn't there be at least for fallback handling ? Something like: if (WARN_ON(spu_acquire(ctx))) return; Christophe > > Signed-off-by: Jason Wang > --- > arch/powerpc/platforms/cell/spufs/sched.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c > index 369206489895..0f218d9e5733 100644 > --- a/arch/powerpc/platforms/cell/spufs/sched.c > +++ b/arch/powerpc/platforms/cell/spufs/sched.c > @@ -904,8 +904,8 @@ static noinline void spusched_tick(struct spu_context *ctx) > struct spu_context *new = NULL; > struct spu *spu = NULL; > > - if (spu_acquire(ctx)) > - BUG(); /* a kernel thread never has signals pending */ > + /* a kernel thread never has signals pending */ > + WARN_ON(spu_acquire(ctx)); > > if (ctx->state != SPU_STATE_RUNNABLE) > goto out; >