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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 752EAECAAD5 for ; Sat, 27 Aug 2022 02:01:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D74DE94000A; Fri, 26 Aug 2022 22:01:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CFE24940007; Fri, 26 Aug 2022 22:01:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B75F094000A; Fri, 26 Aug 2022 22:01:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id A0BBD940007 for ; Fri, 26 Aug 2022 22:01:25 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 794BC80510 for ; Sat, 27 Aug 2022 02:01:25 +0000 (UTC) X-FDA: 79843720530.12.A3A8E48 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf13.hostedemail.com (Postfix) with ESMTP id 396FD2002D for ; Sat, 27 Aug 2022 02:01:23 +0000 (UTC) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MF0J72SNdzGpnw; Sat, 27 Aug 2022 09:59:35 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 10:01:18 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Sat, 27 Aug 2022 10:01:17 +0800 Message-ID: Date: Sat, 27 Aug 2022 10:01:16 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH -next 2/3] mm/zswap: delay the initializaton of zswap until the first enablement Content-Language: en-US To: Nathan Chancellor , Liu Shixin CC: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , , References: <20220825142037.3214152-1-liushixin2@huawei.com> <20220825142037.3214152-3-liushixin2@huawei.com> From: Kefeng Wang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf13.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661565684; a=rsa-sha256; cv=none; b=Yu1lMAco4unJsNKRxaV0iqc5ThAx9qljg0tPoJb+PYWrCU3RIhOk6CXCdYDwPOYCCbWBFC ekT/NwYdzm5j7qREgNO9Z04AV36nRg/OYmPdaukYnUyiToQjLaWgFkKPEi1m0rnPcrGLCG 8H6TZUisdllu8Hzs+GM7V2yDqskXxVc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661565684; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=489qx/oFxJ6QH90MLpHlV6QDxiNItoRtszvB49MYXNc=; b=D4DcdteZ9Xnb8IT54uw5ZMPlhoOeuzfw4OjiC4o/50ULf4H2EqhTg9FR1XR4hs81iWcktL xPXdqN0kSDcVHsMMV7p3r/GmfuFOb+BbXF904SeP7Uk7Ocp57tOEEfEWYMPiJpvV/liuSM ctQrpxZCGoUrxNYcgNtNieetRcUh2ro= X-Rspam-User: X-Rspamd-Queue-Id: 396FD2002D Authentication-Results: imf13.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf13.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Stat-Signature: mfby3ny8um4pssd5czncwkc17dwke3xm X-Rspamd-Server: rspam03 X-HE-Tag: 1661565683-565038 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2022/8/27 4:25, Nathan Chancellor wrote: > Hi Liu, > > On Thu, Aug 25, 2022 at 10:20:36PM +0800, Liu Shixin wrote: >> In the initialization of zswap, about 18MB memory will be allocated for >> zswap_pool in my machine. Since not all users use zswap, the memory may be >> wasted. Save the memory for these users by delaying the initialization of >> zswap to first enablement. >> >> Signed-off-by: Liu Shixin >> --- ... >> This change is in -next as commit 22100432cf14 ("mm/zswap: delay the >> initializaton of zswap until the first enablement"). I just bisected my >> arm64 test system running Fedora failing to boot due to that commit, >> with the following stack trace: >> >> Unable to handle kernel access to user memory outside uaccess routines at virtual address 0000000000000000 >> Mem abort info: >> ESR = 0x0000000096000004 >> EC = 0x25: DABT (current EL), IL = 32 bits >> SET = 0, FnV = 0 >> EA = 0, S1PTW = 0 >> FSC = 0x04: level 0 translation fault >> Data abort info: >> ISV = 0, ISS = 0x00000004 >> CM = 0, WnR = 0 >> user pgtable: 4k pages, 48-bit VAs, pgdp=00000020a4fab000 >> [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 >> Internal error: Oops: 96000004 [#1] SMP >> Modules linked in: zram fsl_dpaa2_eth pcs_lynx phylink ahci_qoriq crct10dif_ce ghash_ce sbsa_gwdt fsl_mc_dpio nvme lm90 nvme_core at803x xhci_plat_hcd rtc_fsl_ftm_alarm xgmac_mdio ahci_platform i2c_imx ip6_tables ip_tables fuse >> Unloaded tainted modules: cppc_cpufreq():1 >> CPU: 10 PID: 761 Comm: swapon Not tainted 6.0.0-rc2-00454-g22100432cf14 #1 >> Hardware name: SolidRun Ltd. SolidRun CEX7 Platform, BIOS EDK II Jun 21 2022 >> pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : frontswap_init+0x38/0x60 >> lr : __do_sys_swapon+0x8a8/0x9f4 >> sp : ffff80000969bcf0 >> x29: ffff80000969bcf0 x28: ffff37bee0d8fc00 x27: ffff80000a7f5000 >> x26: fffffcdefb971e80 x25: ffffaba797453b90 x24: 0000000000000064 >> x23: ffff37c1f209d1a8 x22: ffff37bee880e000 x21: ffffaba797748560 >> x20: ffff37bee0d8fce4 x19: ffffaba797748488 x18: 0000000000000014 >> x17: 0000000030ec029a x16: ffffaba795a479b0 x15: 0000000000000000 >> x14: 0000000000000000 x13: 0000000000000030 x12: 0000000000000001 >> x11: ffff37c63c0aba18 x10: 0000000000000000 x9 : ffffaba7956b8c88 >> x8 : ffff80000969bcd0 x7 : 0000000000000000 x6 : 0000000000000000 >> x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffffaba79730f000 >> x2 : ffff37bee0d8fc00 x1 : 0000000000000000 x0 : 0000000000000000 >> Call trace: >> frontswap_init+0x38/0x60 >> __do_sys_swapon+0x8a8/0x9f4 >> __arm64_sys_swapon+0x28/0x3c >> invoke_syscall+0x78/0x100 >> el0_svc_common.constprop.0+0xd4/0xf4 >> do_el0_svc+0x38/0x4c >> el0_svc+0x34/0x10c >> el0t_64_sync_handler+0x11c/0x150 >> el0t_64_sync+0x190/0x194 >> Code: d000e283 910003fd f9006c41 f946d461 (f9400021) >> ---[ end trace 0000000000000000 ]--- >> >> This is with Fedora's configuration: >> >> https://src.fedoraproject.org/rpms/kernel/raw/rawhide/f/kernel-aarch64-fedora.config >> >> If there is any more information I can provide or patches I can test, I >> am more than happy to do so! Thanks for your reporting，we will check it. > > Cheers, > Nathan > > .