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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 1F496ECE588 for ; Tue, 15 Oct 2019 11:46:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8BC72064B for ; Tue, 15 Oct 2019 11:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571139977; bh=sNE9cceqp0gTpe9FqHpK+Ks+/viCQJhXqeZ7FmQWBd8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=OUfE59yQZclqizQN7Jx/c9/h6BgDtC0V2mLFryVNhFO0hkdlsLklg5tuYAUwaZPud Un+SbLT+goOfNIClVUlHQdKhEQB4NQ0mgO74G/KH+DYIOxzkoIZGZDJr/BIV3K8Mra Ag3Oa0sa8IYZmS7633rLYWGe8sztDpf11G4FE3UU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729150AbfJOLqP (ORCPT ); Tue, 15 Oct 2019 07:46:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:42162 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726208AbfJOLqP (ORCPT ); Tue, 15 Oct 2019 07:46:15 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 41B27AD79; Tue, 15 Oct 2019 11:46:12 +0000 (UTC) Date: Tue, 15 Oct 2019 13:46:11 +0200 From: Michal Hocko To: Anshuman Khandual Cc: linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Greg Kroah-Hartman , Thomas Gleixner , Mike Rapoport , Jason Gunthorpe , Dan Williams , Peter Zijlstra , Mark Rutland , Mark Brown , Steven Price , Ard Biesheuvel , Masahiro Yamada , Kees Cook , Tetsuo Handa , Matthew Wilcox , Sri Krishna chowdary , Dave Hansen , Russell King - ARM Linux , Michael Ellerman , Paul Mackerras , Martin Schwidefsky , Heiko Carstens , "David S. Miller" , Vineet Gupta , James Hogan , Paul Burton , Ralf Baechle , "Kirill A . Shutemov" , Gerald Schaefer , Christophe Leroy , linux-snps-arc@lists.infradead.org, linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V6 2/2] mm/debug: Add tests validating architecture page table helpers Message-ID: <20191015114611.GC317@dhcp22.suse.cz> References: <1571131302-32290-1-git-send-email-anshuman.khandual@arm.com> <1571131302-32290-3-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1571131302-32290-3-git-send-email-anshuman.khandual@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 15-10-19 14:51:42, Anshuman Khandual wrote: > This adds tests which will validate architecture page table helpers and > other accessors in their compliance with expected generic MM semantics. > This will help various architectures in validating changes to existing > page table helpers or addition of new ones. > > Test page table and memory pages creating it's entries at various level are > all allocated from system memory with required size and alignments. But if > memory pages with required size and alignment could not be allocated, then > all depending individual tests are just skipped afterwards. This test gets > called right after init_mm_internals() required for alloc_contig_range() to > work correctly. > > This gets build and run when CONFIG_DEBUG_VM_PGTABLE is selected along with > CONFIG_VM_DEBUG. Architectures willing to subscribe this test also need to > select CONFIG_ARCH_HAS_DEBUG_VM_PGTABLE which for now is limited to x86 and > arm64. Going forward, other architectures too can enable this after fixing > build or runtime problems (if any) with their page table helpers. A highlevel description of tests and what they are testing for would be really appreciated. Who wants to run these tests and why/when? What kind of bugs would get detected? In short why do we really need/want this code in the tree? -- Michal Hocko SUSE Labs