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=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 D0737C433DF for ; Wed, 10 Jun 2020 06:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3EC520801 for ; Wed, 10 Jun 2020 06:25:48 +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="iom6R2+I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726090AbgFJGZr (ORCPT ); Wed, 10 Jun 2020 02:25:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725988AbgFJGZr (ORCPT ); Wed, 10 Jun 2020 02:25:47 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8609C03E96B; Tue, 9 Jun 2020 23:25:46 -0700 (PDT) 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; bh=yhUUkblZBtIukb8ZaU1o3no72vgZVuofYFqFK3m4UNw=; b=iom6R2+I5PdVq8+x/wIT8g6Yps niFdA5pa7du8cSCNo2jTBZC/6ucxC4ER1TSBm7chhc8Wq5BCJxxKNk51jYjeQ7Tm5LsX18T5gQDik mqjD/mKEqlCuSvttI4HMhXs1yuzXIC/IEokWBLce2V33R5tGYzI6jRO39LkT/x5i3R91TSVF3bEj1 rXgM4/moMEH2csodYQyhNIPsyQOY6p1nQcLFKgMeX+KpYyi3cfd1MtA3OMDzkWVamJU39bcJG3gQj xr01uOJ+hYNpbuhbNxVcP7/cE2t7XSuEqguD9NEyHMpy9650uuPLmepXDIvYFVXsMs+u3WC9MWLKs YZoGw4TQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jiuB8-0000hr-LI; Wed, 10 Jun 2020 06:25:38 +0000 Date: Tue, 9 Jun 2020 23:25:38 -0700 From: Christoph Hellwig To: Ritesh Harjani Cc: linux-ext4@vger.kernel.org, jack@suse.com, tytso@mit.edu, Hillf Danton , linux-fsdevel@vger.kernel.org, Borislav Petkov , Marek Szyprowski , syzbot+82f324bb69744c5f6969@syzkaller.appspotmail.com Subject: Re: [PATCHv2 1/1] ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr Message-ID: <20200610062538.GA24975@infradead.org> References: <534f275016296996f54ecf65168bb3392b6f653d.1591699601.git.riteshh@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <534f275016296996f54ecf65168bb3392b6f653d.1591699601.git.riteshh@linux.ibm.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Jun 09, 2020 at 04:23:10PM +0530, Ritesh Harjani wrote: > Simplify reading a seq variable by directly using this_cpu_read API > instead of doing this_cpu_ptr and then dereferencing it. > > This also avoid the below kernel BUG: which happens when > CONFIG_DEBUG_PREEMPT is enabled I see this warning all the time with ext4 using tests VMs, so lets get this fixed ASAP before -rc1: Reviewed-by: Christoph Hellwig