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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9E1CEC43141 for ; Thu, 14 Nov 2019 17:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 703BF206F4 for ; Thu, 14 Nov 2019 17:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726952AbfKNROq (ORCPT ); Thu, 14 Nov 2019 12:14:46 -0500 Received: from mx2.suse.de ([195.135.220.15]:55218 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726482AbfKNROq (ORCPT ); Thu, 14 Nov 2019 12:14:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id B100CACF1; Thu, 14 Nov 2019 17:14:44 +0000 (UTC) Date: Thu, 14 Nov 2019 18:14:43 +0100 From: Joerg Roedel To: Shile Zhang Cc: Michal Hocko , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmalloc: Fix regression caused by needless vmalloc_sync_all() Message-ID: <20191114171443.GB21753@suse.de> References: <20191113095530.228959-1-shile.zhang@linux.alibaba.com> <20191114135641.GA1356@dhcp22.suse.cz> <83a39694-373b-da16-3be1-22108ace0107@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <83a39694-373b-da16-3be1-22108ace0107@linux.alibaba.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 14, 2019 at 10:40:22PM +0800, Shile Zhang wrote: > Could you please help to recall the original issue you encountered before? The original issue was data corruption because old mappings did not get removed from the vmalloc area, and thus also new mappings did not get faulted in. So depending on the page-table currently loaded one vmalloc/ioremap area pointed to different (often already freed or re-used) memory and caused the corruption. Regards, Joerg