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=-17.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 807C9C433B4 for ; Mon, 10 May 2021 16:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64AA361465 for ; Mon, 10 May 2021 16:15:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231402AbhEJQQm (ORCPT ); Mon, 10 May 2021 12:16:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:57799 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231246AbhEJQQg (ORCPT ); Mon, 10 May 2021 12:16:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620663331; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=/I69q7HiZoit2OObK95SvLKEjN8YdPjb7FgV80ugf+k=; b=bF70TG42qsr9xMKcs/wmqQDdARB3JnceAMpZLowOLzeKkZrlAXeau/a15uPhKpTlg0ZHt/ a9jjoHGBJUBh0dDsldW85wh8GGxaSOf2qMP9egZh4+iRI3yPZe/d4hyf5Qs3mbTJnkwdXS IuyItBylb+kRe9KWL/xjsu4ePc5ReZI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-584-QTn26Y4xOfCBw73am4k6hw-1; Mon, 10 May 2021 12:15:26 -0400 X-MC-Unique: QTn26Y4xOfCBw73am4k6hw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D782C8049D6; Mon, 10 May 2021 16:15:24 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.40.196.4]) by smtp.corp.redhat.com (Postfix) with SMTP id B2BE960DBA; Mon, 10 May 2021 16:15:23 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 10 May 2021 18:15:24 +0200 (CEST) Date: Mon, 10 May 2021 18:15:22 +0200 From: Oleg Nesterov To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org Subject: [PATCH] remove the pointless BUG_ON(!task) from wake_up_q() Message-ID: <20210510161522.GA32644@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org because it looks very confusing (to me at least). It is equivalent to BUG_ON(node == offsetof(struct task_struct, wake_q)), unlikely this is what we actually want to check. Signed-off-by: Oleg Nesterov --- kernel/sched/core.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5226cc26a095..61d1d85bb93d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -585,7 +585,6 @@ void wake_up_q(struct wake_q_head *head) struct task_struct *task; task = container_of(node, struct task_struct, wake_q); - BUG_ON(!task); /* Task can safely be re-inserted now: */ node = node->next; task->wake_q.next = NULL; -- 2.25.1.362.g51ebf55