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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,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 808B9C4BA12 for ; Wed, 26 Feb 2020 14:45:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2DBB224692 for ; Wed, 26 Feb 2020 14:45:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=c-s.fr header.i=@c-s.fr header.b="kZ5bMkLJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DBB224692 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BE2816B0003; Wed, 26 Feb 2020 09:45:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B6B816B0005; Wed, 26 Feb 2020 09:45:56 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A34706B0006; Wed, 26 Feb 2020 09:45:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0027.hostedemail.com [216.40.44.27]) by kanga.kvack.org (Postfix) with ESMTP id 875CE6B0003 for ; Wed, 26 Feb 2020 09:45:56 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 565E0824556B for ; Wed, 26 Feb 2020 14:45:56 +0000 (UTC) X-FDA: 76532552712.23.hand33_33b98cfd07221 X-HE-Tag: hand33_33b98cfd07221 X-Filterd-Recvd-Size: 5957 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Wed, 26 Feb 2020 14:45:55 +0000 (UTC) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 48SJWh2b55z9tyg4; Wed, 26 Feb 2020 15:45:52 +0100 (CET) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=kZ5bMkLJ; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id piYm9Kq-bip3; Wed, 26 Feb 2020 15:45:52 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 48SJWh1L1mz9tyg0; Wed, 26 Feb 2020 15:45:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1582728352; bh=BEQC+OIkud+eji3D9C1xajaOV2PnlEzJtZsCBcvukA0=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=kZ5bMkLJJRmtE/zBn7tAG22RVlZ+eB59QhJ/5515+FA1qAhZsJh2OjTNrixj9vTDj g9hhT1i5/9dal9tTCQtAXzKPCb1/TtYD/lHCsid2jxvbbY8kYL0AVDIy3f2yCgUqIz SvUkhU4c68nXEu7I9g1qKkvWUZk1WgTaY/zVbTdo= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 93C978B858; Wed, 26 Feb 2020 15:45:53 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id AccKIxhc_qaM; Wed, 26 Feb 2020 15:45:53 +0100 (CET) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 75D1B8B776; Wed, 26 Feb 2020 15:45:51 +0100 (CET) Subject: Re: [PATCH V14] mm/debug: Add tests validating architecture page table helpers To: Qian Cai , Anshuman Khandual , linux-mm@kvack.org Cc: Andrew Morton , Mike Rapoport , Vineet Gupta , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "Kirill A . Shutemov" , Paul Walmsley , Palmer Dabbelt , linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org References: <1581909460-19148-1-git-send-email-anshuman.khandual@arm.com> <1582726182.7365.123.camel@lca.pw> From: Christophe Leroy Message-ID: <7c707b7f-ce3d-993b-8042-44fdc1ed28bf@c-s.fr> Date: Wed, 26 Feb 2020 15:45:44 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <1582726182.7365.123.camel@lca.pw> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: quoted-printable 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: Le 26/02/2020 =C3=A0 15:09, Qian Cai a =C3=A9crit=C2=A0: > On Mon, 2020-02-17 at 08:47 +0530, Anshuman Khandual wrote: >> This adds tests which will validate architecture page table helpers an= d >> 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. >> >> This test covers basic page table entry transformations including but = not >> limited to old, young, dirty, clean, write, write protect etc at vario= us >> level along with populating intermediate entries with next page table = page >> and validating them. >> >> Test page table pages are allocated from system memory with required s= ize >> and alignments. The mapped pfns at page table levels are derived from = a >> real pfn representing a valid kernel text symbol. This test gets calle= d >> inside kernel_init() right after async_synchronize_full(). >> >> This test gets built and run when CONFIG_DEBUG_VM_PGTABLE is selected.= Any >> architecture, which is willing to subscribe this test will need to sel= ect >> ARCH_HAS_DEBUG_VM_PGTABLE. For now this is limited to arc, arm64, x86,= s390 >> and ppc32 platforms where the test is known to build and run successfu= lly. >> Going forward, other architectures too can subscribe the test after fi= xing >> any build or runtime problems with their page table helpers. Meanwhile= for >> better platform coverage, the test can also be enabled with CONFIG_EXP= ERT >> even without ARCH_HAS_DEBUG_VM_PGTABLE. >> >> Folks interested in making sure that a given platform's page table hel= pers >> conform to expected generic MM semantics should enable the above confi= g >> which will just trigger this test during boot. Any non conformity here= will >> be reported as an warning which would need to be fixed. This test will= help >> catch any changes to the agreed upon semantics expected from generic M= M and >> enable platforms to accommodate it thereafter. >=20 > How useful is this that straightly crash the powerpc? >=20 > [=C2=A0=C2=A0=C2=A023.263425][=C2=A0=C2=A0=C2=A0=C2=A0T1] debug_vm_pgta= ble: debug_vm_pgtable: Validating > architecture page table helpers > [=C2=A0=C2=A0=C2=A023.263625][=C2=A0=C2=A0=C2=A0=C2=A0T1] ------------[= cut here ]------------ > [=C2=A0=C2=A0=C2=A023.263649][=C2=A0=C2=A0=C2=A0=C2=A0T1] kernel BUG at= arch/powerpc/mm/pgtable.c:274! The problem on PPC64 is known and has to be investigated and fixed. Christophe