From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753426AbdC2GnV (ORCPT ); Wed, 29 Mar 2017 02:43:21 -0400 Received: from mail-pg0-f67.google.com ([74.125.83.67]:34464 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751601AbdC2GnT (ORCPT ); Wed, 29 Mar 2017 02:43:19 -0400 Date: Wed, 29 Mar 2017 15:42:06 +0900 From: Sergey Senozhatsky To: Minchan Kim , Yisheng Xie Cc: ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, linux-mm@kvack.org, Linux Kernel Mailing List , Xishi Qiu , Hanjun Guo Subject: Re: [RFC]mm/zsmalloc,: trigger BUG_ON in function zs_map_object. Message-ID: <20170329064206.GA512@tigerII.localdomain> References: <20170329002029.GA18979@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170329002029.GA18979@bbox> User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (03/29/17 09:20), Minchan Kim wrote: > Hello, > > On Tue, Mar 28, 2017 at 03:20:22PM +0800, Yisheng Xie wrote: > > Hi, all, > > > > We had backport the no-lru migration to linux-4.1, meanwhile change the > > ZS_MAX_ZSPAGE_ORDER to 3. Then we met a BUG_ON(!page[1]). > > Hmm, I don't know how you backported. > > There isn't any problem with default ZS_MAX_ZSPAGE_ORDER. Right? > So, it happens only if you changed it to 3? I agree with Minchan. too much things could have gone wrong during the backport. > Could you tell me what is your base kernel? and what zram/zsmalloc > version(ie, from what kernel version) you backported to your > base kernel? agree again. Yisheng, do you have this commit applied? commit c102f07ca0b04f2cb49cfc161c83f6239d17f491 Author: Junil Lee Date: Wed Jan 20 14:58:18 2016 -0800 zsmalloc: fix migrate_zspage-zs_free race condition -ss