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=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED 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 67DD6C1B0F2 for ; Wed, 20 Jun 2018 09:18:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22888208A6 for ; Wed, 20 Jun 2018 09:18:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AEqU61ph" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22888208A6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754798AbeFTJSQ (ORCPT ); Wed, 20 Jun 2018 05:18:16 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:60474 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753594AbeFTJR7 (ORCPT ); Wed, 20 Jun 2018 05:17:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=eMR7ibTmNe3ELDK64esigCjsQC4vZ1gIcPqREVgCnZk=; b=AEqU61ph9g6gnWPKf+wdsQvn2 72+NWq3ih/NAd75Bpruke9Ker9fOHNJOgAoXn0pLTC1qEGMJEtNcrWGEJSRIeJITCCUenAwbucHpB Qs3OP4zA7KyXkHSdtsisJbGOt2Rew3WDjYKX/xd4oTpfngIIZka8ynpL7CvDsK85RZ11GSaOkfzxw q1INf38HksTau737ccrhVORjIJvXOHD/dP2t0jBAk3Lq+ww/kNi0qKWmL5bN4P5tDP8H8J/Yure+j UHEpqb0EQTEj0aw0+NcNVgfJar53RssQ4im5mYMz8sjBjofuMz+WuBeuiet9szkU9XodCZLNoUXb2 tMdsd7t1A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fVZFR-00007G-Tu; Wed, 20 Jun 2018 09:17:54 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 496122029F1DD; Wed, 20 Jun 2018 11:17:52 +0200 (CEST) Date: Wed, 20 Jun 2018 11:17:52 +0200 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, Davidlohr Bueso , Dan Williams , Arnd Bergmann , linux-nfs@vger.kernel.org Subject: Re: [PATCH] locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS Message-ID: <20180620091752.GL2476@hirez.programming.kicks-ass.net> References: <1527168398-4291-1-git-send-email-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1527168398-4291-1-git-send-email-longman@redhat.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 24, 2018 at 09:26:38AM -0400, Waiman Long wrote: > It was found that the use of up_read_non_owner() in NFS was causing > the following warning when DEBUG_RWSEMS was configured. > > DEBUG_LOCKS_WARN_ON(sem->owner != ((struct task_struct *)(1UL << 0))) > > Looking into the rwsem.c file, it was discovered that the corresponding > down_read_non_owner() function was not setting the owner field properly. > This is fixed now, and the warning should be gone. > > Signed-off-by: Waiman Long Acked-by: Peter Zijlstra (Intel) > --- > kernel/locking/rwsem.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c > index bc1e507..776308d 100644 > --- a/kernel/locking/rwsem.c > +++ b/kernel/locking/rwsem.c > @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem) > might_sleep(); > > __down_read(sem); > + rwsem_set_reader_owned(sem); > } > > EXPORT_SYMBOL(down_read_non_owner); > -- > 1.8.3.1 >