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=BAYES_00,DKIM_SIGNED, DKIM_VALID,FSL_HELO_FAKE,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 C495BC433FE for ; Thu, 10 Dec 2020 17:55:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8814F23D57 for ; Thu, 10 Dec 2020 17:55:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392935AbgLJRy3 (ORCPT ); Thu, 10 Dec 2020 12:54:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392178AbgLJRyZ (ORCPT ); Thu, 10 Dec 2020 12:54:25 -0500 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64BC6C0613CF for ; Thu, 10 Dec 2020 09:53:45 -0800 (PST) Received: by mail-pf1-x443.google.com with SMTP id q22so4798256pfk.12 for ; Thu, 10 Dec 2020 09:53:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=G4hUloSQ1uQEQVeNiYcMiD6uCkefrUn6s2yR1vrm4IA=; b=KFa74gTQMPUdpakVO9A2B2hGnYzp+hXxTrHtYe94CVkOwC4T0gmeZYB4fh2sqFv5cz YWb17tIXVdnG9mgYyTjW8Tgru9PxmFBJFtIIslm65MvOSHAMfH2BKRQUYmYat9UWMAgF Akwj1wVUmZMzJYEj+s1x8IcUvXdb3UcJsoYrCefAENvO6Bmp6P7COsHb+pz28CVyYnPR cZmeDkUCc/5t3dqYLCszMXjKQZbWbFM1BbvN9BSpJuZYjMmMoE2zYkmBrhDh/lNL14Uf rZPbJ1LLRpTgnUbr3saTa0hTzTniZcBeJDjsrE6soR/fNMpt7xLqBMumi+R5JcvAyLYi D6Nw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=G4hUloSQ1uQEQVeNiYcMiD6uCkefrUn6s2yR1vrm4IA=; b=U+UuNIWnJAGDns9xVBc565WaW44WLrUQUvRE3GL7MCfnczHxA5vx9oESQJLexQVnYv 6Lx72rOdo0pjCFiEy6fRPHvHHVLkqC/dSlwyLJrt9wUkmCg4yO3QvCjpAmjN6c88sZmD ok5SgVw25mvXjCeHHrzdxOGisDg0p94MLGdCYQsC4jKBdamMVGOTLecpQEpuyR8MV7NW bySnkaNISHZRWpH/AF+KSkJzxTY/JUHvO5knUWEOfjCPYLgSS0B1fAYVAByxUBXt+X9q oZ/dSJZQzka2rGsWTE4VoO1jAh9An+oEm9yG4BhqyfVrfMLrfLrXvEuT/r1S9D2qEuBz Emsg== X-Gm-Message-State: AOAM533i/AeRAmCbCv2dlU4+LZWXg40V3VSNukjb75k3+NLk6uCkvqFG bMyPYWAvvtSSAiMkCge9rQTBOz/6880= X-Google-Smtp-Source: ABdhPJw2PF3ijuQODLvCWMGgOSYZUGCgg7Noqn6XxaybthIIabaSokloTV6DGuMentaB/uJe1U9HMg== X-Received: by 2002:a17:90a:730b:: with SMTP id m11mr4480422pjk.76.1607622824942; Thu, 10 Dec 2020 09:53:44 -0800 (PST) Received: from google.com ([2620:15c:211:201:7220:84ff:fe09:5e58]) by smtp.gmail.com with ESMTPSA id b11sm7105138pjl.41.2020.12.10.09.53.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Dec 2020 09:53:44 -0800 (PST) Sender: Minchan Kim Date: Thu, 10 Dec 2020 09:53:42 -0800 From: Minchan Kim To: gregkh@linuxfoundation.org Cc: akpm@linux-foundation.org, harish@linux.ibm.com, hch@infradead.org, sergey.senozhatsky@gmail.com, stable@vger.kernel.org, tony@atomide.com, torvalds@linux-foundation.org, urezki@gmail.com Subject: Re: FAILED: patch "[PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING" failed to apply to 5.4-stable tree Message-ID: References: <160750482424034@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <160750482424034@kroah.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, Dec 09, 2020 at 10:07:04AM +0100, gregkh@linuxfoundation.org wrote: > > The patch below does not apply to the 5.4-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From e91d8d78237de8d7120c320b3645b7100848f24d Mon Sep 17 00:00:00 2001 > From: Minchan Kim > Date: Sat, 5 Dec 2020 22:14:51 -0800 > Subject: [PATCH] mm/zsmalloc.c: drop ZSMALLOC_PGTABLE_MAPPING > > While I was doing zram testing, I found sometimes decompression failed > since the compression buffer was corrupted. With investigation, I found > below commit calls cond_resched unconditionally so it could make a > problem in atomic context if the task is reschedule. > > BUG: sleeping function called from invalid context at mm/vmalloc.c:108 > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 946, name: memhog > 3 locks held by memhog/946: > #0: ffff9d01d4b193e8 (&mm->mmap_lock#2){++++}-{4:4}, at: __mm_populate+0x103/0x160 > #1: ffffffffa3d53de0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0xa98/0x1160 > #2: ffff9d01d56b8110 (&zspage->lock){.+.+}-{3:3}, at: zs_map_object+0x8e/0x1f0 > CPU: 0 PID: 946 Comm: memhog Not tainted 5.9.3-00011-gc5bfc0287345-dirty #316 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 > Call Trace: > unmap_kernel_range_noflush+0x2eb/0x350 > unmap_kernel_range+0x14/0x30 > zs_unmap_object+0xd5/0xe0 > zram_bvec_rw.isra.0+0x38c/0x8e0 > zram_rw_page+0x90/0x101 > bdev_write_page+0x92/0xe0 > __swap_writepage+0x94/0x4a0 > pageout+0xe3/0x3a0 > shrink_page_list+0xb94/0xd60 > shrink_inactive_list+0x158/0x460 > > We can fix this by removing the ZSMALLOC_PGTABLE_MAPPING feature (which > contains the offending calling code) from zsmalloc. > > Even though this option showed some amount improvement(e.g., 30%) in > some arm32 platforms, it has been headache to maintain since it have > abused APIs[1](e.g., unmap_kernel_range in atomic context). > > Since we are approaching to deprecate 32bit machines and already made > the config option available for only builtin build since v5.8, lastly it > has been not default option in zsmalloc, it's time to drop the option > for better maintenance. > > [1] http://lore.kernel.org/linux-mm/20201105170249.387069-1-minchan@kernel.org > > Fixes: e47110e90584 ("mm/vunmap: add cond_resched() in vunmap_pmd_range") This patch fixex e47110e90584 which merged at v5.9 so we could drop it for v5.4. Thanks.