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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0CE6C433EF for ; Fri, 15 Oct 2021 08:56:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 685A9610D1 for ; Fri, 15 Oct 2021 08:56:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 685A9610D1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id D4344900002; Fri, 15 Oct 2021 04:56:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CCB966B0080; Fri, 15 Oct 2021 04:56:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BBABC900002; Fri, 15 Oct 2021 04:56:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0195.hostedemail.com [216.40.44.195]) by kanga.kvack.org (Postfix) with ESMTP id A8CED6B007E for ; Fri, 15 Oct 2021 04:56:12 -0400 (EDT) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3AC44180260EB for ; Fri, 15 Oct 2021 08:56:12 +0000 (UTC) X-FDA: 78698064984.31.E8AC7FE Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf23.hostedemail.com (Postfix) with ESMTP id AC43F90000A7 for ; Fri, 15 Oct 2021 08:56:09 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id BAD2E61053; Fri, 15 Oct 2021 08:56:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634288170; bh=Q7ariDqv81ESrlC2dW0PuAyGJAandYcqDaiSNHfbxQQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uHWFxjgN0j6uy54kk+PuKWsQXZAravsfZY8pZKixqTo8/t9859egP1Fzz/r/UFP3j pKRuamEiuY/Dwc/+QpnfWTf/sWNNfhMwZbVWxVfub1kH4CRYdWRn5CQYjdbgLCac9o sh7ORqtEfm9q5AKGtzFZlP/kLNO/R2oFHLN3PRlxsXtO7/HYTzofgjq4C072XXT9lh KbGmTC7vqWacVxEn3eNhUgZ/EA7McQ1YvxSRGhlsTVouHPeADKh3UBp0IaceH36bIf Y9c+6PGwmjdmSCJ0ZadDxaYmKgTuJ65zPH3wNm8vQE6+zKn5B8ls+d97XXK85PZn9u zx39wdy59p99g== Date: Fri, 15 Oct 2021 11:55:58 +0300 From: Mike Rapoport To: Vlastimil Babka Cc: kernel test robot , 0day robot , Dmitry Vyukov , Marco Elver , Vijayanand Jitta , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Geert Uytterhoeven , Oliver Glitta , Imran Khan , LKML , lkp@lists.01.org, Andrew Morton , linux-mm@kvack.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kasan-dev@googlegroups.com Subject: Re: [lib/stackdepot] 1cd8ce52c5: BUG:unable_to_handle_page_fault_for_address Message-ID: References: <20211014085450.GC18719@xsang-OptiPlex-9020> <4d99add1-5cf7-c608-a131-18959b85e5dc@suse.cz> <137e4211-266f-bdb3-6830-e101c27c3be4@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <137e4211-266f-bdb3-6830-e101c27c3be4@suse.cz> X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: AC43F90000A7 X-Stat-Signature: esor388mugq43k3tehnd794ykpij93kz Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=uHWFxjgN; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf23.hostedemail.com: domain of rppt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=rppt@kernel.org X-HE-Tag: 1634288169-261159 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 Fri, Oct 15, 2021 at 10:27:17AM +0200, Vlastimil Babka wrote: > On 10/14/21 12:16, Mike Rapoport wrote: > > On Thu, Oct 14, 2021 at 11:33:03AM +0200, Vlastimil Babka wrote: > >> On 10/14/21 10:54, kernel test robot wrote: > >> > >> In my local testing of the patch, when stackdepot was initialized through > >> page owner init, it was using kvmalloc() so slab_is_available() was true. > >> Looks like the exact order of slab vs page_owner alloc is non-deterministic, > >> could be arch-dependent or just random ordering of init calls. A wrong order > >> will exploit the apparent fact that slab_is_available() is not a good > >> indicator of using memblock vs page allocator, and we would need a better one. > >> Thoughts? > > > > The order of slab vs page_owner is deterministic, but it is different for > > FLATMEM and SPARSEMEM. And page_ext_init_flatmem_late() that initializes > > page_ext for FLATMEM is called exactly between buddy and slab setup: > > Oh, so it was due to FLATMEM, thanks for figuring that out! > > > static void __init mm_init(void) > > { > > ... > > > > mem_init(); > > mem_init_print_info(); > > /* page_owner must be initialized after buddy is ready */ > > page_ext_init_flatmem_late(); > > kmem_cache_init(); > > > > ... > > } > > > > I've stared for a while at page_ext init and it seems that the > > page_ext_init_flatmem_late() can be simply dropped because there is anyway > > a call to invoke_init_callbacks() in page_ext_init() that is called much > > later in the boot process. > > Yeah, but page_ext_init() only does something for SPARSEMEM, and is empty on > FLATMEM. Otherwise it would be duplicating all the work. So I'll just move > page_ext_init_flatmem_late() below kmem_cache_init() in mm_init(). I hope at some point we'll have cleaner mm_init(), but for now simply moving page_ext_init_flatmem_late() should work. > Thanks again! Welcome :) -- Sincerely yours, Mike.