Received: by 2002:a25:683:0:0:0:0:0 with SMTP id 125csp260946ybg; Tue, 9 Jun 2020 23:26:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyIQQxPjN+AXdzSH6zwEwiOs8x+st1H8OCxBTSjEGBMHDPcd9iiBcRJXl3omlSZCYJMq070 X-Received: by 2002:a50:d78f:: with SMTP id w15mr1198489edi.245.1591770390252; Tue, 09 Jun 2020 23:26:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1591770390; cv=none; d=google.com; s=arc-20160816; b=qeEMsfZYEe7zvgIoBDqOAIMit9a1izUoEgi4nE/SQMkXoXlNGX3W0FEXPTAnhOLuge RR+KUw/u7yJzTniHkmfkFkLacVExO5HCB2OW7DGJ5oN+gLtK4eeMIgMwwGr0jx54ZUos DDa396LfZXgnUUksf0HssYe1srC1OoBaWSidfkL6nQFcHfJJQoPT4F0hdxAu6dknFW9/ ge+QLoQFS+/EmgXXdLW82OOMXs60kOpb3n0TNDIbsNgt2DvaeKodCD5JUan2TpS3rTYr 4u8Vn1urW/Ka3M546kS9AlSIv3hXQApxJ5npokVZvfzZLpWQg45rSLZcCsUw/Y8cxPaL fmgQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :dkim-signature; bh=yhUUkblZBtIukb8ZaU1o3no72vgZVuofYFqFK3m4UNw=; b=OOsqsWZdDftGWFIXK0mqg3/2PKzVw1VjJMCWOPbblTlh8c+tPI1Xetr7zcJDmpmCmL 7nfAqrOS8pJwgCZvBskUdtymi6CjIVxNB4/g68WEmF2hNIFw9ZcEvXeGihUeEYt37ke7 gUasa9UU48S/7YCGKf0PWo+EfhxypjNpEftedE0Fll+QNoJFq+/G0jky2iEtgnLpJHud QS9j7UqAZ8QhJpLpNivKd/MjuOWV217bwf7DtS4kZAoQm42q6/Jd8iIbuj031I/c4vaf uLC2VUU2ltQgqg5U48X9D+ndrL/AFZDhsi0WFF/2Rs+92em0LHp0VGDVlUJvIC4LBndX aRBw== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=iom6R2+I; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id v25si4564772edq.70.2020.06.09.23.25.54; Tue, 09 Jun 2020 23:26:30 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=fail header.i=@infradead.org header.s=bombadil.20170209 header.b=iom6R2+I; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726076AbgFJGZr (ORCPT + 99 others); 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-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@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