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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 915EEC6377D for ; Thu, 22 Jul 2021 06:37:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ECC596024A for ; Thu, 22 Jul 2021 06:37:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECC596024A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C3086B0036; Thu, 22 Jul 2021 02:37:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 04B056B005D; Thu, 22 Jul 2021 02:37:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E39D46B006C; Thu, 22 Jul 2021 02:37:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0068.hostedemail.com [216.40.44.68]) by kanga.kvack.org (Postfix) with ESMTP id C4BC56B0036 for ; Thu, 22 Jul 2021 02:37:18 -0400 (EDT) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 728F12030F for ; Thu, 22 Jul 2021 06:37:18 +0000 (UTC) X-FDA: 78389266956.30.F567F41 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf12.hostedemail.com (Postfix) with ESMTP id 12E591006650 for ; Thu, 22 Jul 2021 06:37:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1626935837; h=from:from:reply-to: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=T5yJXoswrtbBl372z9LAdEWN+q1EKTxAfgwD664hR5E=; b=SKDkPUPjKk2rrWt8P2f40VkiKt5yiuEcXAE/cUqu0ui/nwDqdO9ipplkx/HkKCFxCzGPaL f0nY8jxPI5y5N5HaUut0VxVhbnsH2ksXZGoUrCRnlQ8KCaDYoy6EMl+8tHnCA9XYTUIhjS /FzvAh0kqLGhUdKJ6cnrP2M8q+RHACY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-454-LpOZS3vyP86UpbiWH7jigA-1; Thu, 22 Jul 2021 02:37:15 -0400 X-MC-Unique: LpOZS3vyP86UpbiWH7jigA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 96B1A802575; Thu, 22 Jul 2021 06:37:14 +0000 (UTC) Received: from [10.64.54.195] (vpn2-54-195.bne.redhat.com [10.64.54.195]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A989E5D6D1; Thu, 22 Jul 2021 06:37:10 +0000 (UTC) Reply-To: Gavin Shan Subject: Re: [PATCH v3 07/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PTE modifying tests To: Anshuman Khandual , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210719130613.334901-1-gshan@redhat.com> <20210719130613.334901-8-gshan@redhat.com> From: Gavin Shan Message-ID: <99c73652-7294-17ff-0c4f-986b588ab022@redhat.com> Date: Thu, 22 Jul 2021 16:37:26 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 12E591006650 X-Stat-Signature: uu6pjqghtzisbxn5os6nrxue6zm3czh7 Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=SKDkPUPj; spf=none (imf12.hostedemail.com: domain of gshan@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=gshan@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-HE-Tag: 1626935837-633239 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: Hi Anshuman, On 7/22/21 3:56 PM, Anshuman Khandual wrote: > On 7/19/21 6:36 PM, Gavin Shan wrote: >> This uses struct pgtable_debug_args in PTE modifying tests. The allocated >> page is used as set_pte_at() is used there. The tests are skipped if >> the allocated page doesn't exist. Besides, the unused variable @ptep >> and @pte_aligned in debug_vm_pgtable() are dropped. > > Please dont drop @ptep and @pte_aligned just yet. > We need to do so. Otherwise, there are build warning raised to complain something like 'unused variable'. >> >> Signed-off-by: Gavin Shan >> --- >> mm/debug_vm_pgtable.c | 75 ++++++++++++++++++++++--------------------- >> 1 file changed, 39 insertions(+), 36 deletions(-) >> >> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c >> index d32e55a95c55..eb6dda88e0d9 100644 >> --- a/mm/debug_vm_pgtable.c >> +++ b/mm/debug_vm_pgtable.c >> @@ -116,10 +116,7 @@ static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx) >> WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte)))); >> } >> >> -static void __init pte_advanced_tests(struct mm_struct *mm, >> - struct vm_area_struct *vma, pte_t *ptep, >> - unsigned long pfn, unsigned long vaddr, >> - pgprot_t prot) >> +static void __init pte_advanced_tests(struct pgtable_debug_args *args) >> { >> pte_t pte; >> >> @@ -130,33 +127,38 @@ static void __init pte_advanced_tests(struct mm_struct *mm, >> */ >> >> pr_debug("Validating PTE advanced\n"); >> - pte = pfn_pte(pfn, prot); >> - set_pte_at(mm, vaddr, ptep, pte); >> - ptep_set_wrprotect(mm, vaddr, ptep); >> - pte = ptep_get(ptep); >> + if (args->pte_pfn == ULONG_MAX) { >> + pr_debug("%s: Skipped\n", __func__); >> + return; >> + } > > Just return. Please dont call out "Skipped". Also this check should be > performed before printing pr_debug("Validating PTE advanced\n"). The > print indicates that the test has started. > Sure. >> + >> + pte = pfn_pte(args->pte_pfn, args->page_prot); >> + set_pte_at(args->mm, args->vaddr, args->ptep, pte); >> + ptep_set_wrprotect(args->mm, args->vaddr, args->ptep); >> + pte = ptep_get(args->ptep); >> WARN_ON(pte_write(pte)); >> - ptep_get_and_clear(mm, vaddr, ptep); >> - pte = ptep_get(ptep); >> + ptep_get_and_clear(args->mm, args->vaddr, args->ptep); >> + pte = ptep_get(args->ptep); >> WARN_ON(!pte_none(pte)); >> >> - pte = pfn_pte(pfn, prot); >> + pte = pfn_pte(args->pte_pfn, args->page_prot); >> pte = pte_wrprotect(pte); >> pte = pte_mkclean(pte); >> - set_pte_at(mm, vaddr, ptep, pte); >> + set_pte_at(args->mm, args->vaddr, args->ptep, pte); >> pte = pte_mkwrite(pte); >> pte = pte_mkdirty(pte); >> - ptep_set_access_flags(vma, vaddr, ptep, pte, 1); >> - pte = ptep_get(ptep); >> + ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); >> + pte = ptep_get(args->ptep); >> WARN_ON(!(pte_write(pte) && pte_dirty(pte))); >> - ptep_get_and_clear_full(mm, vaddr, ptep, 1); >> - pte = ptep_get(ptep); >> + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); >> + pte = ptep_get(args->ptep); >> WARN_ON(!pte_none(pte)); >> >> - pte = pfn_pte(pfn, prot); >> + pte = pfn_pte(args->pte_pfn, args->page_prot); >> pte = pte_mkyoung(pte); >> - set_pte_at(mm, vaddr, ptep, pte); >> - ptep_test_and_clear_young(vma, vaddr, ptep); >> - pte = ptep_get(ptep); >> + set_pte_at(args->mm, args->vaddr, args->ptep, pte); >> + ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); >> + pte = ptep_get(args->ptep); >> WARN_ON(pte_young(pte)); >> } >> >> @@ -617,20 +619,24 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, >> } >> #endif /* PAGETABLE_P4D_FOLDED */ >> >> -static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, >> - unsigned long pfn, unsigned long vaddr, >> - pgprot_t prot) >> +static void __init pte_clear_tests(struct pgtable_debug_args *args) >> { >> - pte_t pte = pfn_pte(pfn, prot); >> + pte_t pte; >> >> pr_debug("Validating PTE clear\n"); >> + if (args->pte_pfn == ULONG_MAX) { >> + pr_debug("%s: Skipped\n", __func__); >> + return; >> + } > > Just return. Please dont call out "Skipped". Also this check should be > performed before printing pr_debug("Validating PTE clear\n"). The print > indicates that the test has started. > Sure. >> + >> + pte = pfn_pte(args->pte_pfn, args->page_prot); > > Please keep this unchanged and move to its original position. > Ok. >> #ifndef CONFIG_RISCV >> pte = __pte(pte_val(pte) | RANDOM_ORVALUE); >> #endif >> - set_pte_at(mm, vaddr, ptep, pte); >> + set_pte_at(args->mm, args->vaddr, args->ptep, pte); >> barrier(); >> - pte_clear(mm, vaddr, ptep); >> - pte = ptep_get(ptep); >> + pte_clear(args->mm, args->vaddr, args->ptep); >> + pte = ptep_get(args->ptep); >> WARN_ON(!pte_none(pte)); >> } >> >> @@ -1150,11 +1156,10 @@ static int __init debug_vm_pgtable(void) >> p4d_t *p4dp, *saved_p4dp; >> pud_t *pudp, *saved_pudp; >> pmd_t *pmdp, *saved_pmdp, pmd; >> - pte_t *ptep; >> pgtable_t saved_ptep; >> pgprot_t prot; >> phys_addr_t paddr; >> - unsigned long vaddr, pte_aligned, pmd_aligned; >> + unsigned long vaddr, pmd_aligned; >> unsigned long pud_aligned; >> spinlock_t *ptl = NULL; >> int idx, ret; >> @@ -1189,10 +1194,8 @@ static int __init debug_vm_pgtable(void) >> */ >> paddr = __pa_symbol(&start_kernel); >> >> - pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT; > > Please dont drop pte_aligned just yet. > We need to drop the variable. Otherwise, there is build warning to complain: 'unused variable'. >> pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT; >> pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; >> - WARN_ON(!pfn_valid(pte_aligned)); > > This should go into init_args() at the right place as the following, > after evaluating it from 'start_kernel' symbol - just to be sure. > > WARN_ON(!pfn_valid(args->fixed_pte_pfn)) > Yes. >> >> pgdp = pgd_offset(mm, vaddr); >> p4dp = p4d_alloc(mm, pgdp, vaddr); >> @@ -1272,11 +1275,11 @@ static int __init debug_vm_pgtable(void) >> * Page table modifying tests. They need to hold >> * proper page table lock. >> */ >> - >> - ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl); >> - pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); >> - pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); >> - pte_unmap_unlock(ptep, ptl); >> + ptl = pte_lockptr(args.mm, args.pmdp); >> + spin_lock(ptl); >> + pte_clear_tests(&args); >> + pte_advanced_tests(&args); >> + spin_unlock(ptl); > > Why pte_offset_map_lock()/pte_unmap_unlock() has been dropped and > spin_lock()/spin_unlock() sequence has been added ? Please dont > change the tests in these patches. > The semantics of pte_offset_map_lock() is to grab and take the lock and return the PTE entry, which is mapped if needed. We already had the PTE entry tracked by args->ptep in init_args(). So some of the operations covered by pte_offset_map_lock() isn't needed any more. >> >> ptl = pmd_lock(mm, pmdp); >> pmd_clear_tests(mm, pmdp); >> > Thanks, Gavin