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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B3B2C4332F for ; Fri, 11 Nov 2022 09:29:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233703AbiKKJ3z (ORCPT ); Fri, 11 Nov 2022 04:29:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233700AbiKKJ3d (ORCPT ); Fri, 11 Nov 2022 04:29:33 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 152A6116; Fri, 11 Nov 2022 01:29:32 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C95E222237; Fri, 11 Nov 2022 09:29:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1668158970; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=N1dVUIpFQi8O7Feo048ZZ65SBEEuoI/CXn0xkHOeIQ8=; b=LZdrByDsfEwPhehQVcHHbocAJpkj6zR2HNxwZf7CERcVw9IZNSpweoj2AjG27HK+t/ZCBX mZj4iULIoNXFmrloqCiJmx8LLzvB82fWehyAZyEqQKyXc8eCHrc5kNSipU7vdsNeEHkZ1k p7kw37TBqMli/YQkAQpbe/zmXj4HSLU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1668158970; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=N1dVUIpFQi8O7Feo048ZZ65SBEEuoI/CXn0xkHOeIQ8=; b=ntvSU9jJFb8JO/N/C45DbT7XTcQeW8VRLcv/T1eopJaPSfX3aijtLJ7dx94qOUCXaxZ0E5 0E9hnRihOKha/ECQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 6A04B13273; Fri, 11 Nov 2022 09:29:30 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id JCK3GPoVbmOQYgAAMHmgww (envelope-from ); Fri, 11 Nov 2022 09:29:30 +0000 Date: Fri, 11 Nov 2022 10:29:28 +0100 From: Petr Vorel To: Minchan Kim Cc: ltp@lists.linux.it, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Nitin Gupta , Sergey Senozhatsky , Jens Axboe , OGAWA Hirofumi , Martin Doucha , Yang Xu Subject: Re: [PATCH 0/1] Possible bug in zram on ppc64le on vfat Message-ID: Reply-To: Petr Vorel References: <20221107191136.18048-1-pvorel@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Mon, Nov 07, 2022 at 10:47:33PM +0100, Petr Vorel wrote: > > Hi Minchan, > > > On Mon, Nov 07, 2022 at 08:11:35PM +0100, Petr Vorel wrote: > > > > Hi all, > > > > following bug is trying to workaround an error on ppc64le, where > > > > zram01.sh LTP test (there is also kernel selftest > > > > tools/testing/selftests/zram/zram01.sh, but LTP test got further > > > > updates) has often mem_used_total 0 although zram is already filled. > > > Hi, Petr, > > > Is it happening on only ppc64le? > > I haven't seen it on other archs (x86_64, aarch64). > > > Is it a new regression? What kernel version did you use? > > Found on openSUSE kernel, which uses stable kernel releases 6.0.x. > > It's probably much older, first I've seen it some years ago (I'm not able to find kernel version), but it was random. Now it's much more common. > > Test runs on VM (I can give qemu command or whatever you need to know about it) > > I'll try to verify it on some bare metal ppc64le. > Hi Petr and Martin, > Thanks for testing and meaning information. > Could you tell how I could create VM to run ppc64le and run the test? > I'd like to reproduce in my local to debug it. I suppose you don't have ppc64le bare metal machine, thus you run on x86_64. One way would be to install on host qemu-system-ppc64, download iso image of any distro which supports ppc64le and install it with virt-manager (which would fill necessary qemu params). Other way, which I often use is to compile system with Buildroot distribution. You can clone my Buildroot distro fork, branch debug/zram [1]. I put there in 3 commits my configuration. I added 0001-zram-Debug-mm_stat_show.patch [2] on the top of 6.0.7 with little debugging. What is now only needed is to 1) install on host qemu-system-ppc64 (speedup build + Buildroot is configured not to compile qemu-system-ppc64), then: $ make # takes time $ ./output/images/start-qemu.sh serial-only When I have ppc64le host with enough space, I often use rapido [3], but that crashed stable kernel (another story which I'll report soon). Hope that helps. Kind regards, Petr [1] https://github.com/pevik/buildroot/commits/debug/zram [2] https://github.com/pevik/buildroot/blob/debug/zram/0001-zram-Debug-mm_stat_show.patch [3] https://github.com/rapido-linux/rapido