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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 343E9C4338F for ; Wed, 28 Jul 2021 11:07:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17CDA60F45 for ; Wed, 28 Jul 2021 11:07:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235896AbhG1LHT (ORCPT ); Wed, 28 Jul 2021 07:07:19 -0400 Received: from foss.arm.com ([217.140.110.172]:55138 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231994AbhG1LHS (ORCPT ); Wed, 28 Jul 2021 07:07:18 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B56C631B; Wed, 28 Jul 2021 04:07:16 -0700 (PDT) Received: from [10.163.65.183] (unknown [10.163.65.183]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5B3773F66F; Wed, 28 Jul 2021 04:07:13 -0700 (PDT) Subject: Re: [PATCH v4 06/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in migration and thp tests To: Gavin Shan , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, gerald.schaefer@linux.ibm.com, aneesh.kumar@linux.ibm.com, christophe.leroy@csgroup.eu, cai@lca.pw, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210727061401.592616-1-gshan@redhat.com> <20210727061401.592616-7-gshan@redhat.com> From: Anshuman Khandual Message-ID: <39de75d2-744a-9194-cbc2-14926b60e68e@arm.com> Date: Wed, 28 Jul 2021 16:38:02 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210727061401.592616-7-gshan@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/27/21 11:43 AM, Gavin Shan wrote: > This uses struct pgtable_debug_args in the migration and thp test > functions. It's notable that the pre-allocated page is used in > swap_migration_tests() as set_pte_at() is used there. > > Signed-off-by: Gavin Shan > --- > mm/debug_vm_pgtable.c | 28 ++++++++++++++-------------- > 1 file changed, 14 insertions(+), 14 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index bc153cad9045..9136195efde3 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -845,7 +845,7 @@ static void __init pmd_swap_tests(struct pgtable_debug_args *args) > static void __init pmd_swap_tests(struct pgtable_debug_args *args) { } > #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ > > -static void __init swap_migration_tests(void) > +static void __init swap_migration_tests(struct pgtable_debug_args *args) > { > struct page *page; > swp_entry_t swp; > @@ -861,9 +861,10 @@ static void __init swap_migration_tests(void) > * problematic. Lets allocate a dedicated page explicitly for this > * purpose that will be freed subsequently. > */ > - page = alloc_page(GFP_KERNEL); > + page = (args->pte_pfn != ULONG_MAX) ? > + pfn_to_page(args->pte_pfn) : NULL; > if (!page) { > - pr_err("page allocation failed\n"); > + pr_err("no page available\n"); > return; > } Please check for a valid page earlier in the function and return. Otherwise this calls out the page unavailability (after starting the test), which is inconsistent with all other functions like pxx_advanced_tests(). [ 1.051633] debug_vm_pgtable: [pte_swap_tests ]: Validating PTE swap [ 1.052697] debug_vm_pgtable: [pmd_swap_tests ]: Validating PMD swap [ 1.053765] debug_vm_pgtable: [swap_migration_tests ]: Validating swap migration <===== [ 1.054900] debug_vm_pgtable: [swap_migration_tests ]: no page available <===== Should do this just before pr_info("Validating swap migration\n"). ...... page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL; if (!page) return; .....